Giles Simpson, M.D.

• Assistant Professor of Emergency Medicine
• Mount Sinai Hospital
• Chicago, IL

This theory suggests the possibility of overactive dopaminergic pathways in the basal nuclei (basal ganglia) antibiotic while pregnant buy cephalexin 250mg online, an area of the brain responsible for starting and stopping synchronized motor activity such as leg and arm motions during walking antimicrobial body wash purchase 250mg cephalexin amex. Symptoms of schizophrenia seem to be associated with dopamine type 2 (D2) receptors antibiotic 6 month old buy genuine cephalexin. The basal nuclei are particularly rich in D2 receptors treatment for dogs cataracts buy cephalexin 500 mg without a prescription, whereas the cerebrum contains very few antibiotic or antifungal cephalexin 500 mg generic. Most antipsychotic drugs act by entering dopaminergic synapses and competing with dopamine for receptors infection from pedicure buy cheap cephalexin 500 mg line. By blocking D2 receptors, antipsychotic drugs reduce the symptoms of schizophrenia. The majority of these children present with mental health disorders such as anxiety, depression, bipolar disorder, or attention deficit/hyperactivity disorder 2 years prior to the onset of psychotic symptoms (Kalapatapu, 2011). Many patients do not view their behavior as abnormal and have difficulty understanding the need for drug therapy. When a medication produces undesirable adverse effects, such as severe muscle twitching or sexual dysfunction, patients stop taking it and relapse to experience their former symptoms. Agitation, distrust, and extreme frustration are common because patients cannot comprehend why others are unable to think as they do or see the same things that they see. This includes obtaining and holding employment and maintaining satisfactory interpersonal relationships. This level of success in treatment requires setting many small, realistic benchmarks that the patient, caregiver, and health care provider can achieve. These subgoals nearly always involve pharmacotherapy as well as establishing effective psychological and social support. Initial treatment: the first psychotic episode may occur suddenly or it may be preceded by a long period of subacute symptoms such as depression or withdrawal from normal activities. If the patient is exhibiting agitation or aggressiveness or presenting a physical danger to others, the first doses of the antipsychotic drug may be higher than normal. High doses produce sedation, which is normally viewed as an adverse effect but which is therapeutic in combative patients. Lorazepam produces fewer serious adverse effects than antipsychotic agents and allows the dose of the antipsychotic drug to be reduced. Acute symptoms usually resolve in 3 to 7 days, at which time the patient is switched to maintenance therapy. Maintenance treatment: the pharmacotherapy of psychosis is a long-term process, with symptoms resolving gradually. Some symptoms resolve faster than others, depending on the patient and specific drug used. A patient or caregiver may notice improvement in acute symptoms after less than a week of therapy. After 2 to 4 weeks, there is usually improvement in mood, socialization, and the ability to provide self-care. Patients who have experienced untreated schizophrenia for many years are slower to respond than those experiencing their first episode. As long as symptoms continue to gradually improve, the patient is maintained on a stable dosage. If substantial improvement is not observed after 8 to 12 weeks of therapy, the health care provider must explore reasons for the lack of response. For example, the patient may not be taking the medication, or the original diagnosis may have been incorrect. If the patient has been taking the medication at average doses or higher, the health care provider will generally not increase the dose because doing so increases the potential for serious adverse effects. Instead of increasing the dosage, a different antipsychotic drug may be substituted. The nurse, patient, and caregivers must understand that drug therapy is not a cure; in some cases, medications simply are not able to eliminate all psychotic symptoms. The answer to this is highly individualized, but the most common answer is for the lifetime of the patient. In patients experiencing their first acute episode, health care providers may slowly taper the dose after a year of successful therapy. Abrupt cessation of some antipsychotics can cause serious withdrawal symptoms, including nightmares, nausea, vomiting, salivation, sweating, and nervousness. When discontinuation is attempted, the patient should be monitored carefully and the drug restarted at the first sign of relapse. Approximately 15% to 25% of patients with psychoses can successfully stop drug therapy without returning to their former symptoms. Discontinuation is not usually attempted in patients with long-standing chronic psychosis. Nonadherence: Patients with serious mental illness have a very high nonadherence rate. Unless they are deemed overtly dangerous to themselves or other people, patients cannot be held for long periods of hospitalization against their wishes. Once the patient returns to the community, he or she may discontinue taking the drug and not return for follow-up appointments. Lack of insight into their illness causes patients with psychosis to view their behavior as normal. Patients with paranoia may feel that drug therapy is a plot by others to poison them and keep them from thinking clearly. Even motivated patients who understand the need for continuous drug therapy may have difficulty tolerating the adverse effects. The nurse member of the treatment team must be diligent in teaching caregivers about means of maximizing adherence to the pharmacotherapeutic regimen and how to recognize signs of nonadherence. Another factor causing nonadherence with medications for schizophrenia is the desire to drink alcohol. Some patients use alcohol in an attempt to elevate their mood or to decrease symptoms of schizophrenia. However, alcohol can interact with some antipsychotic medications and cause a suboptimal response. Because studies have confirmed that alcohol worsens psychotic symptoms, patients should be instructed to avoid alcohol use. Nonpharmacologic therapies: Psychotherapy is an essential component of the total care of the patient with psychosis. Family and caregiver training are included in the plan of care for the treatment of patients with schizophrenia whenever feasible. Prognosis: Although there is no cure, schizophrenia can be successfully managed in a significant number of patients. Strong family and caregiver support, combined with pharmacotherapy, can decrease hospitalization and relapse rates and increase the potential for recovery. This essentially ended the era of placing all patients in insane asylums for their lifetimes. The second-generation or atypical antipsychotic agents were discovered in the 1970s and 1980s. The conventional group is further subdivided by chemical classes into phenothiazines and nonphenothiazines. This older classification scheme has flaws because there is not always a clear distinction between a drug that is "conventional" and one that is "atypical. This system divides these agents by potency levels: low potency (drugs that require higher doses), moderate potency (drugs that require middle range dosing), and high potency (drugs able to control symptoms of schizophrenia with low doses). This categorization was made based on the amount of medication necessary to produce an equivalent effect as compared to other drugs in the same category. As an example, 100 mg of chlorpromazine is approximately equivalent to 2 mg of haloperidol (Haldol). According to the categories, haloperidol is a high-potency drug, whereas chlorpromazine is a low-potency drug (although both are conventional antipsychotics). So for the antipsychotic drugs, which classification should the student learn and use Because the conventional and atypical and potency methods of drug classification are used in clinical practice, the student must be aware of both schemes. Drug selection: In terms of effectiveness, there is no single drug of choice for the long-term therapy of schizophrenia. Selection of a specific drug is based on clinician experience, the occurrence of adverse effects, and the therapeutic response of each individual patient. Men who are sexually active may adhere better to a regimen with a drug that does not cause sexual dysfunction. Clearly, the second-generation atypical antipsychotics result in a lower incidence of serious adverse effects and have become preferred drugs for psychosis. The experience and skills of the health care provider and mental health nurse are particularly valuable in achieving successful psychiatric pharmacotherapy. For example, risperidone (Risperdal Consta), paliperidone (Invega Sustenna), and fluphenazine decanoate last 2 to 6 weeks, depending on the dose and patient response. Major tranquilizer was the term used following the introduction of the first-generation agents because sedation is a prominent action of these agents. Neuroleptic is a term used to denote drugs that have effects on the nervous system, especially those that have Parkinson-like adverse effects on posture and body movement. Although the student will still encounter reference sources that refer to these drugs as tranquilizers or neuroleptics, antipsychotic is more accurate and is the preferred term. Although many symptoms of psychosis can be controlled with drugs, adverse effects are common and often serious. Whereas the pyramidal system controls visible, voluntary movements, the extrapyramidal system is associated with postural and automatic movements that are not usually noticeable. They generally occur during long-term therapy, and symptoms may persist for months or years after the drug is discontinued. Symptoms include high fever, diaphoresis, muscle rigidity, tachycardia, and blood pressure fluctuations. Although rare, without quick, aggressive treatment the condition can rapidly deteriorate to stupor or coma. Adverse effects on the reproductive system are a major cause of nonadherence to the drug regimen in some patients. Up to 50% to 60% of men taking antipsychotics may experience ejaculation and erectile dysfunction. Many antipsychotics increase serum levels of the hormone prolactin, which can cause secretion of breast milk (galactorrhea) and breast enlargement (gynecomastia). Most women will also experience menstrual dysfunction due to the high prolactin levels. They also have a wide safety margin between a therapeutic and a lethal dose; Acute dystonia occurs early in the course of pharmaco- therapy with antipsychotics and involves severe muscle spasms, particularly of the back, neck, tongue, and face. In rare cases, acute dystonia can be so severe as to dislocate joints and impair respiration due to laryngospasm. Administration of drugs with anticholinergic properties such as diphenhydramine (Benadryl) or benztropine (Cogentin) can reverse acute dystonia symptoms within minutes when administered parenterally. For dystonia refractory to anticholinergic drugs, diazepam (Valium) may be administered. The patient paces, has trouble sitting or remaining still, and has difficulty sleeping. Repetitive movements such as rocking while standing or sitting and crossing and uncrossing legs may be evident. Beta-adrenergic blockers such as propranolol (Inderal), anticholinergics, and benzodiazepines have been used to treat symptoms of akathisia. Parkinsonism induced by antipsychotic drugs may include tremor, loss of fine motor skills, muscle rigidity, stooped posture, and a shuffling gait. The treatment of antipsychotic drug-induced parkinsonism includes anticholinergic drugs and amantadine (Symmetrel) (see Chapter 25). Involuntary, unusual movements of the tongue and face and lip-smacking movements; may include involuntary movements of the arms and legs, fingers, toes, and trunk. Treatment should not need to be continued for more than a few months, because symptoms should resolve. For some patients, decreased doses of antipsychotics, administration of benzodiazepines, or gradual withdrawal of anticholinergics may help. The first-generation or conventional antipsychotics are classified as phenothiazines or nonphenothiazines. Phenothiazine is a chemical term that refers to compounds with three rings that are joined together by nitrogen and sulfur atoms. Originally developed as a yellow dye in the 1800s, phenothiazine became the starting molecule for a series of drugs, which are recognized by the "-zine" suffix. The student will encounter the term phenothiazine in other chapters because several drug classes produce "phenothiazine-like" adverse effects. At equivalent doses, all phenothiazines have the same effectiveness in treating psychoses, and all produce a similar spectrum of adverse effects. Selection of a specific phenothiazine is determined by the severity and extent of expected adverse effects. If the patient is driving or working, fluphenazine may be selected because it produces less sedation and fewer anticholinergic effects than other phenothiazines. Levodopa (Dopar, Larodopa) is usually avoided because its ability to increase dopamine function antagonizes the mechanism of action of the phenothiazines. Beta-adrenergic blockers and benzodiazepines are sometimes given to reduce signs of akathisia. The phenothiazines reduce nausea and vomiting by blocking dopamine receptors in the chemoreceptor trigger zone in the medulla. They are most often used for treating the severe nausea and vomiting associated with cancer chemotherapy. This condition is characterized by tics: sudden, loud vocalizations, often cursing, and muscle movements such as twitches, kicking, or hitting. The patient feels a premonitory urge, a type of warning, that a tic is forthcoming, and the tics may be consciously suppressed for limited periods. Drugs from a large number of classes have been used to suppress tics, including phenothiazines.

In 2010 an enzyme medication infection x ray discount cephalexin 500mg on-line, collagenase (Xiaflex) antibiotics sinus infection yeast infection purchase generic cephalexin on-line, was approved to treat this disorder virus living or non living order 250 mg cephalexin free shipping. This enzyme is injected multiple times into the affected cord treatment for dogs conjunctivitis order cephalexin discount, over a 4-week interval antibiotics for acne infection purchase cephalexin 250 mg otc. The most frequently reported adverse effects are swelling of the affected hand antibiotics for dogs after giving birth order 250mg cephalexin amex, contusion, injection-site reaction or hemorrhage, and localized pain. Effective therapies for spasticity include the administration of medications and the implementation of physical therapy. Routine and consistent physical therapy exercises provide the patient with increased muscle movement and decreased severity of symptoms. Effective physical therapy exercises include muscle stretching, which assists in the prevention of contractures. The implementation of muscle group strengthening and repetitive motion exercises improve accuracy. Baclofen (Lioresal) and tizanidine (Zanaflex) are centrally acting muscle relaxants that also are effective in treating spasticity. Dantrolene (Dantrium), botulinum toxin type A (Botox), and botulinum toxin type B (Myobloc) act directly on skeletal muscle to relieve spasticity. The mechanism of action of direct-acting antispasmodics is shown in Pharmacotherapy Illustrated 27. It can affect someone at any stage of the life span (American Dystonia Society, 2011). A patient with malignant hyperthermia will experience a sudden onset of tachycardia, ventricular dysrhythmia, and hypotension. This is due to the rapid release of calcium ions in muscle cells, which produces hypermetabolism and intense muscle rigidity. The muscle metabolic rate becomes so elevated that it quickly raises the body temperature to a dangerous level. It is important for the anesthesia provider and circulating nurse to have phentolamine (Regitine) available in the event of extravasation of dantrolene. There is a strong genetic predisposition to malignant hyperthermia, and patients with a family history of the disorder should not receive drugs that have the potential to cause this adverse effect. Classification: Therapeutic: Direct-acting skeletal muscle relaxant, antispasticity agent Pharmacologic: Calcium release blocker (muscle cells) Therapeutic Effects and Uses: Approved in 1974, dantrolene is a direct-acting skeletal muscle relaxant indicated for spasticity, especially for spasms of the head and neck muscles. Dantrolene produces a 50% decrease in the degree of contraction of skeletal muscle without producing effects on the cardiac or smooth muscle. When administered parenterally it relieves symptoms of malignant hyperthermia related to general anesthesia. Mechanism of Action: Dantrolene is a hydantoin derivative structurally related to phenytoin (Dilantin), an antiepileptic drug. Other adverse effects include xerostomia, dizziness, nausea, photosensitivity, diarrhea, tachycardia, erratic blood pressure, and urinary retention. Black Box Warning: Dantrolene is hepatotoxic and deaths due to liver failure have occurred in patients taking this drug. The lowest possible effective dose should be used to avoid hepatotoxicity and the drug should be discontinued if no therapeutic effect is noted after 45 days of treatment. Contraindications/Precautions: There are no contraindications to the use of dantrolene in treating malignant hyperthermia because this is a fatal condition if left untreated. For spasticity, dantrolene is contraindicated in patients with preexisting hepatic disease. Because it can cause muscle weakness, dantrolene should not be used when spasticity is necessary to sustain an upright position or balance when standing or walking. Dantrolene should be used cautiously in the presence of impaired cardiac or pulmonary function. The risk of dantrolene-induced hepatotoxicity is greatest in women over the age of 35; thus it should be administered cautiously in these patients. Lifespan and Diversity Considerations: Use special caution in administering this drug to the older adult who is at increased risk of falls, and provide assistance with ambulation as needed. Patient and Family Education: Be aware that the therapeutic effects of dantrolene may not be seen for 1 week. Drugs Similar to Dantrolene (Dantrium) Botulinum toxins are also direct-acting muscle relaxants. Botulinum toxin (Botox, Botox Cosmetic, Dysport, Myobloc, Xeomin): Botulinum toxin is an unusual drug obtained from Clostridium botulinum, the gram-positive bacterium responsible for botulism. The drug blocks neuromuscular transmission by binding to motor nerve terminals and inhibiting the release of acetylcholine. Without sufficient amounts of acetylcholine, the muscle is unable to contract and flaccid paralysis occurs. Each of the formulations differs in potency and they may not be interchanged or substituted for each other. For each of these indications, small doses are injected into the affected muscles. The most recent approval in 2010 was for the prophylaxis of chronic migraine headaches, when other therapies are ineffective. Because of the extreme weakness associated with botulinum, therapies may be needed to improve muscle strength. To circumvent major problems with mobility or posture, administration of botulinum toxin is often limited to the small muscle groups. In general, botulinum therapy is well tolerated and adverse effects are related to the dose injected in each muscle. Calcium channel blockers such as verapamil (Calan) place the patient at increased risk of ventricular fibrillation and cardiovascular collapse when dantrolene sodium is administered intravenously. Treatment of Overdose: Overdose with dantrolene results in muscle weakness, lethargy, and coma. General supportive measures are administered until the effects of the drug diminish. From what you learned in Chapter 17, what are the symptoms of this disorder and what is the primary pharmacotherapy During many surgical procedures it is necessary to produce total skeletal muscle relaxation in the patient. Skeletal muscle relaxants such as succinylcholine (Anectine) and tubocurarine are administered in combination with anesthetic agents to induce skeletal muscle relaxation, which aids in intubation and other invasive procedures. These agents are also administered to facilitate endoscopy, to enhance the management of mechanical ventilation, and to control the severity of muscle contractions resulting from electroshock therapy. The skeletal muscle relaxants used as surgical adjuncts have the ability to produce complete muscle paralysis; thus mechanical ventilation may be necessary. Most of these drugs have very rapid onsets of action and brief half-lives; drug effects rapidly diminish following the surgical procedure. The skeletal muscle relaxants used as surgical adjuncts are presented in Chapter 18. Prototype features for succinylcholine and tubocurarine are found in that chapter. Source: Jo Ann Snover/Shutterstock Another drawback is the pain experienced by patients when it is injected directly into the muscle. The severity of pain experienced can be blocked by the administration of a local anesthetic. The therapeutic effects of botulinum therapy are effective within 6 weeks and last for only 3 to 6 months. Assess the history of pain associated with muscle spasms and what has worked successfully or not for the patient in the past. Assessment throughout administration: Assess for desired therapeutic effects dependent on the reason for the drug. Potential Nursing Diagnoses Pain: Acute, Chronic Impaired Physical Mobility Self-Care Deficit: Bathing, Feeding, Dressing, Toileting Disturbed Body Image Fatigue Deficient Knowledge, (Drug Therapy) Risk for Injury, related to disease condition, adverse drug effects Planning: Patient Goals and Expected Outcomes the patient will: Experience therapeutic effects dependent on the reason the drug is being given. Support the patient in self-care activities as necessary until improvement is observed. Nonpharmacologic measures may be needed until the full medication effect is noted. Particular care with ambulation is required because pain, spasms, or rigidity may increase the risk of falls. Be particularly cautious with older adults who are at increased risk for hypotension. Notify the health care provider if the blood pressure decreases beyond established parameters, or if hypotension is accompanied by reflex tachycardia. Significantly diminished or absent bowels sounds are immediately reported to the health care provider. If other sedatives or antihypertensives are ordered, have the patient consult with the health care provider about dose and sequencing. Dose should be taken consistently and not prn for best results unless otherwise ordered. Encourage the patient to maintain a medication log, noting symptoms along with dose and timing of medications and bring the log to each health care visit. On arising today he stated that his back hurts and he cannot move from side to side. Rinse the mouth frequently with an alcohol-based mouthwash to relieve excess secretions. A client with spastic cerebral palsy is being treated with oral baclofen (Lioresal). A client has been treated for cervical dystonia with an injection of botulinum toxin type A (Botox). Continuous spasms and pain on the affected side A client has been taking cyclobenzaprine (Amrix, Flexeril) for muscle spasms. The client is admitted to the emergency department with severe central nervous system depression. Physostigmine (Antilirium) A female client, age 45, is receiving dantrolene sodium (Dantrium) for treatment of painful muscle spasms associated with multiple sclerosis. Create a list of adverse effects that this patient may experience due to botulinum therapy. Costeffectiveness of intrathecal baclofen therapy for the treatment of severe spasticity associated with cerebral palsy. Intrathecal baclofen in children with spastic cerebral palsy: A doubleblind, randomized, placebo-controlled, dosefinding study. Practice parameter: Pharmacologic treatment of spasticity in children and adolescents with cerebral palsy. Describe the general actions, and pharmacotherapeutic applications of central nervous system stimulants. Identify the signs and symptoms of attention deficit/hyperactivity disorder and narcolepsy. Compare and contrast the central nervous system stimulants and nonstimulants in treating attention deficit/hyperactivity disorder. Apply the nursing process to care for patients receiving central nervous system stimulants. The stimulants range from widely accessible agents (caffeine) to Schedule I controlled substances (ecstasy). Mood is often elevated, and the person may temporarily become unaware of physical fatigue. For some of the controlled substances, mood elevation may progress to euphoria, an intense sense of happiness and well-being. With continued use, physical and psychological dependence occur with these agents. Stimulants have the potential to cause adverse effects due to excessive excitation. Nervousness, dizziness, and irritability are common, and convulsions may occur at higher doses. Most of the stimulants also affect the cardiovascular system and can increase heart rate and cause dysrhythmias. Albuterol (Proventil) inhalers are used anorexiants, 416 for asthma but the drug may attention deficit/ cause nervousness, tremors, hyperactivity and anxiety. They produce many potentially serious adverse effects, including physical and psychological dependence. Six or more of the following symptoms of inattention have been present for at least 6 months to a point that is disruptive and inappropriate for developmental level: Inattention 1. Often does not give close attention to details or makes careless mistakes in schoolwork, work, or other activities. Often does not follow instructions and fails to finish schoolwork, chores, or duties in the workplace (not due to oppositional behavior or failure to understand instructions). Six or more of the following symptoms of hyperactivity-impulsivity have been present for at least 6 months to an extent that is disruptive and inappropriate for developmental level: Hyperactivity 1. Often runs about or climbs when and where it is not appropriate (adolescents or adults may feel very restless). There must be clear evidence of significant impairment in social, school, or work functioning. The symptoms do not happen only during the course of a pervasive developmental disorder, schizophrenia, or other psychotic disorder. It is characterized by symptoms of impulsive behavior, lack of attention, and hyperactivity. The symptoms of inattention and hyperactivity also contribute to difficulty with peer and family relationships. Hyperactive children usually have increased motor activity with impulsivity and a tendency to interrupt at inappropriate times. Some additional symptoms noted include difficulty remembering details and the placement of personal items, changing tasks without completing prior tasks, and disturbances in sleep.

Hyponatremia caused by excessive dilution is treated with loop diuretics antibiotic resistance correlates with transmission in plasmid evolution discount cephalexin 500 mg line, which will remove the fluid overload that caused the hyponatremia (see Chapter 35) bacteria are the simplest single cells that order cephalexin 250mg otc. In 2009 bacteria 7th grade buy 500mg cephalexin otc, tolvaptan (Samsca) was approved to quickly raise serum sodium levels in hospitalized patients experiencing symptoms of hyponatremia antibiotics for uti delay period order cephalexin 500mg overnight delivery. Tolvaptan is a vasopressin (antidiuretic hormone) antagonist that enhances renal sodium and water excretion antibiotic resistance wildlife discount cephalexin 500mg on line. The sodium ions in the drug are widely distributed and excreted by the kidneys in the same manner as endogenous sodium ions antibiotic for sinus infection starts with l cheap 500mg cephalexin mastercard. Adverse Effects: Patients receiving NaCl infusions must be monitored frequently to avoid symptoms of hypernatremia, which include lethargy, confusion, muscle tremor or rigidity, hypotension, and restlessness. Because some of these symptoms are also common to hyponatremia, periodic laboratory assessments must be taken to be certain that sodium values are moving toward the normal range. When infusing 3% NaCl solutions, the nurse should continuously check for signs of pulmonary edema. Contraindications/Precautions: this drug should not be administered to patients with hypernatremia, heart failure, or impaired renal function. Sodium Chloride (NaCl) Drug Interactions: There are no clinically significant drug interactions. Classification: Therapeutic: Agent for hyponatremia Pharmacologic: Electrolyte, sodium supplement Pregnancy: Category C. If excess fluid accumulation has occurred, diuretics may be administered to remove excess sodium ion and water to reduce pulmonary or peripheral edema. Therapeutic Effects and Uses: Sodium chloride is administered for hyponatremia when serum levels fall below 130 mEq/L. The drug is available in several concentrations; the decision on which NaCl concentration to administer is driven by the severity of the sodium deficiency. When serum sodium falls below 115 mEq/L, a highly concentrated 3% NaCl solution may be infused. In conjunction with oxytocin, 20% NaCl may be used as an abortifacient late in pregnancy when instilled into the amniotic sac. Drugs Similar to Sodium Chloride (NaCl) There is no other drug similar to sodium chloride. Potassium is the most abundant intracellular cation; 98% of the potassium present in the body is found inside cells, with the majority found in skeletal muscle. Potassium serves critical roles in muscular contraction and the conduction of nerve impulses. To prevent imbalances, adequate dietary intake of potassium must be carefully balanced to potassium excretion. Patients with normal diets consume plenty of potassium for bodily functions because the mineral is abundant in fruits, vegetables, and meats. As serum potassium levels rise, the pancreas secretes additional insulin, which causes the ion to move out of the plasma and into cells, thus preventing hyperkalemia. In a typical feedback loop, as serum potassium levels fall, insulin secretion is diminished. As the blood becomes acidic, the body attempts to raise plasma pH by pumping hydrogen ions (H) into cells. This can raise the serum Mechanism of Action: Sodium chloride is a replacement solution for lost sodium. Maintaining Fluid Balance During Exercise Hyponatremia from excessive fluid intake has been noted as a growing problem in athletes, particularly novice athletes who may have heard that they need to "keep drinking" to maintain hydration. Many sports drinks contain some electrolytes but are also high in fructose or other sugars. This creates a hypertonic solution that may paradoxically cause increased water loss. Unless exercise is extreme or prolonged, athletes, especially children, should be encouraged to drink when thirsty and maintain urine at a color of clear yellow, not dark yellow or colorless. This is sometimes called a false hyperkalemia because the total body potassium is not actually increased; it has just shifted from intracellular to extracellular spaces. Potassium ion is freely filtered at the glomerulus, but is entirely reabsorbed as it travels along the kidney tubule. In the distal tubule, however, potassium is secreted back into the renal tubule and exits in the urine. Like sodium, potassium excretion is influenced by the actions of aldosterone on the kidney. For every sodium ion that is reabsorbed, one potassium ion is secreted into the renal tubules. Both hyper- and hypokalemia are associated with fatal dysrhythmias and serious neuromuscular disorders. Because over 98% of potassium is intracellular, serum potassium may not be an accurate reflection of total body potassium. Hyperkalemia: Hyperkalemia occurs when the serum potassium level rises above 5 mEq/L. This condition may be caused by excessive consumption of potassium-rich foods or dietary supplements, particularly when patients are taking potassiumsparing diuretics such as spironolactone (see Chapter 35). In fact, overtreatment with potassium supplements is the most common cause of hyperkalemia. Excess potassium may also accumulate when renal excretion is diminished due to kidney pathology. The most serious consequences of hyperkalemia are related to cardiac function: dysrhythmias and heart block. Other symptoms are muscle twitching, fatigue, paresthesias, dyspnea, cramping, and diarrhea. In mild cases of hyperkalemia, potassium levels may be returned to normal by restricting primary dietary sources of potassium such as bananas, citrus and dried fruits, peanut butter, broccoli, and green leafy vegetables. All potassium supplements and the use of salt substitutes containing potassium should be discontinued. If the patient is taking a potassiumsparing diuretic, the dose must be lowered, or a thiazide or loop diuretic substituted. Administration of the diuretic furosemide (Lasix) can significantly increase the urinary excretion of potassium within 5 to 15 minutes. Administering glucose or dextrose concurrently with insulin temporarily lowers serum potassium levels by causing potassium to leave the extracellular fluid and enter cells. In all patients who are symptomatic, calcium gluconate or calcium chloride is administered to prevent or treat potassium-induced cardiotoxicity. Sodium bicarbonate is sometimes infused to correct any acidosis that may be concurrent with the hyperkalemia. Excess potassium may also be eliminated from the body by giving polystyrene sulfonate (Kayexalate) orally or rectally. This agent, which is not absorbed, exchanges sodium ion for potassium ion as it travels through the intestine. The onset of action is 1 hour, and the dose may be repeated every 4 hours as needed. The drug is given concurrently with a laxative such as sorbitol to promote rapid evacuation of the potassium. Hypokalemia: Hypokalemia is one of the most common electrolyte imbalances and occurs when the serum potassium level falls below 3. The most frequent cause of hypokalemia is pharmacotherapy with loop and thiazide diuretics. In addition, strenuous muscular activity and severe vomiting or diarrhea can lead to significant potassium loss. Because the body does not have large stores of potassium, adequate daily dietary intake is necessary. Neurons and muscle fibers are most sensitive to potassium loss, and muscle weakness, lethargy, anorexia, dysrhythmias, and cardiac arrest are possible consequences. Mild hypokalemia is treated by increasing the dietary intake of potassium-rich foods. The foods highest in potassium content include dried fruit, nuts, molasses, avocados, lima beans, and bran cereals. If increasing dietary intake is not possible, a large number of potassium products are available for oral supplementation. The most common supplements are the chloride salts, because these supply both potassium and chloride, which are lost during diuretic therapy. Liquid preparations are very effective, although many must be diluted with water or fruit juices prior to administration. Extended release (K-Dur 20, Slow-K, Micro-K) and powders (Klor-Con) are also available. Oral formulations of potassium chloride include tablets, powders, and liquids, usually heavily flavored due to its unpleasant taste. Because potassium supplements can cause peptic ulcers, the drug should be diluted with plenty of water. Mechanism of Action: Potassium chloride is a replacement solution for lost potassium. Pharmacokinetics: Because potassium chloride is a natural electrolyte, it is not possible to obtain accurate pharmacokinetic values. The potassium ions in the drug are widely distributed and excreted by the kidneys in the same manner as endogenous potassium ions. The most serious adverse effects of potassium chloride are related to the possible accumulation of excess potassium. Hyperkalemia may occur if the patient takes potassium supplements concurrently with potassium-sparing diuretics. Contraindications/Precautions: Potassium chloride is contraindicated in patients with hyperkalemia, systemic acidosis, severe dehydration, extensive tissue breakdown as in severe burns, or adrenal insufficiency. The drug should be used with extreme caution in patients with chronic or acute renal failure because the drug may accumulate to high levels. Avoid licorice because large amounts can cause potassium depletion and sodium retention. Avoid salt substitutes unless specifically ordered by the health care provider because these contain potassium. Potassium bicarbonate supplies bicarbonate ion, which is alkaline and may be useful in treating acidosis. Potassium citrate makes the urine less acidic and is primarily used to reduce the formation of kidney stones. Potassium gluconate is commonly available in tablet form and dissociates to potassium ion and gluconate ion, a form of glucose. Drug Interactions: Potassium supplements should not be administered to patients who are taking potassium-sparing diuretics because hyperkalemia may result. Treatment of Overdose: Potassium-sparing diuretics and all foods and medications containing potassium should be withheld. Magnesium is the second most abundant intracellular cation and, like potassium, it is essential for proper neuromuscular function. Magnesium also serves a metabolic role in activating certain enzymes in the breakdown of carbohydrates and proteins; it is a cofactor in over 300 biochemical reactions. Patients with disorders of magnesium homeostasis generally present with cardiovascular and neuromuscular symptoms. Because the majority of magnesium is found in bone, serum magnesium levels are not accurate indicators of total body magnesium. The ion is freely filtered and reabsorbed in the loop of Henle and loop diuretics such as furosemide can cause significant magnesium loss. Magnesium is absorbed by the small intestine and small amounts are secreted in intestinal fluid. Lifespan and Diversity Considerations: Use special caution in administering potassium to the older adult who is at increased risk of hyperkalemia due to age-related renal changes. Patient and Family Education: Swallow the tablet with a large glass of water or fruit juice (if allowed). Do not crush or chew potassium tablets, although the pills may be large and hard to swallow. Although the overall incidence for magnesium deficiency is 6% to 12%, the majority of critically ill patients present with this condition. Renal causes of hypomagnesemia include kidney failure and therapy with loop diuretics. Hypomagnesemia may also present in alcoholics and in those receiving prolonged parenteral feeding with magnesium-free solutions. Pharmacotherapy with magnesium sulfate can quickly reverse symptoms of hypomagnesemia. Hypermagnesemia: Advanced renal failure is the only major cause of hypermagnesemia, although overtreatment with magnesium supplements may also lead to excessive serum magnesium levels. Infusions of calcium salts will immediately reverse the neuromuscular and cardiovascular signs. If the magnesium elevation is minor, treatment with furosemide to increase urinary excretion may be sufficient to reverse the hypermagnesemia. Early signs of magnesium overdose include flushing of the skin, sedation, confusion, intense thirst, and muscle weakness. Extreme levels cause neuromuscular blockade with resultant respiratory paralysis, heart block, and circulatory collapse.

Purchase cephalexin 500 mg. C3SD Mariel Reyes Antiséptico Soluprep.

Syndromes

• Contracture deformities (for example, at the fingers, elbows, and knees) and other deformities
• Infection
• Familial dysbetalipoproteinemia
• Keep any appointments that you have made with your regular doctor and transplant team.
• Cough
• General anesthesia. You will be asleep and pain-free.
• Sometimes, CT scans are used as an alternative to a regular colonoscopy. This is called a virtual colonoscopy.
• Diarrhea (bloody)
• A family history of connective tissue disorders (such as Marfan syndrome)
• Fibrates (gemfibrozil, fenofibrate)

Extensively used in the treatment of thromboembolic disease antibiotic wash order 500 mg cephalexin with mastercard, anticoagulants lengthen clotting time and prevent thrombi from forming or growing larger antibiotic 800mg discount cephalexin online master card. Since thromboembolic disease can be life threatening bacteria resistant to antibiotics discount cephalexin line, therapy is often begun by administering anticoagulants parenterally to achieve the most rapid onset of action antibiotic treatment for mrsa discount 250mg cephalexin with amex. As the disease stabilizes and the desired degree of anticoagulation has been achieved infection knee joint buy cephalexin 500mg cheap, the patient is gradually switched to oral anticoagulants virus for kids best order for cephalexin, with careful monitoring of appropriate coagulation laboratory values. Traditionally, the most frequently prescribed parenteral anticoagulant has been heparin; warfarin is the most common oral anticoagulant (see Section 41. As a drug, heparin has been used for many decades and is one of the few agents still obtained from animal tissue, usually beef lung or pig intestine. This drug is also called unfractionated heparin because it contains a mixture of different molecular "fractions. As its name implies, antithrombin inactivates thrombin (as well as several other clotting factors). Because responses to heparin anticoagulation vary considerably among patients, regular monitoring of laboratory values during heparin therapy is essential to patient safety. Given subcutaneously, the mechanism of action of these agents is very similar to that of heparin, except the shorter heparin molecules are unable to bind thrombin, making them more selective for Factor Xa inhibition. They produce a more predictable anticoagulant response than heparin because there is less binding of the drug to proteins and macrophages; therefore, less frequent laboratory monitoring is required. They are about 10 times less likely to cause thrombocytopenia, a potentially serious adverse effect of heparin. They also exhibit a half-life that is two to four times longer than heparin that permits once-daily dosing, and family members or the patient can be trained to give the necessary subcutaneous injections at home. In highly unstable patients or those with renal impairment, measurement of antifactor Xa activity may be used to gauge therapeutic response. Subcutaneous heparin is injected into the deep fatty layers of the abdomen and may take up to 1 hour to achieve a therapeutic effect. Heparin is also used to maintain the patency of peripheral catheters (heparin locks) and arterial lines. Heparin prolongs coagulation time, thereby inhibiting excessive clotting within blood vessels. As a result, it prevents the enlargement of existing clots and the formation of new ones. Clotting time is prolonged, although bleeding time is only affected at high doses. Because these can result in long-term or permanent paralysis, frequent monitoring for neurologic impairment is essential. More severe symptoms usually appear after 5 to 10 days of therapy; thus, frequent blood laboratory testing should be conducted during this period. Although the half-life of heparin is brief, it may take a week after the drug is discontinued for platelets to recover. Because heparin is derived from animal sources, hypersensitivity reactions are possible. Osteoporosis has been reported in patients taking the drug longer than 30 days, and may be severe enough to cause bone fractures. Some heparin products may contain sulfites and should not be administered to patients with sulfite sensitivity. Although relatively safe during pregnancy, the drug should be used with caution during the peripartum period due to the risk of maternal hemorrhage. Caution must be used when administering heparin to patients with serious renal or hepatic impairment because the drug may rise to toxic levels. To a lesser extent, and by a separate mechanism, heparin also inactivates Factor Xa. Other clotting factors are affected by heparin, but these have little clinical significance. Drugs that inhibit platelet aggregation (such as aspirin, indomethacin, and ibuprofen) may induce bleeding. Herbal/Food: Herbal supplements that may affect coagulation such as ginger, garlic, green tea, feverfew, or ginkgo should be avoided because they may increase the risk of bleeding. Distribution Primary metabolism Primary excretion Onset of action Duration of action Pregnancy: Category C. Adverse Effects: Abnormal bleeding is common with heparin therapy, occurring in about 10% of patients, and is the most serious adverse effect. Lifespan and Diversity Considerations: Monitor hepatic function laboratory values more frequently in the older adult because normal physiological changes related to aging may affect the metabolism of the drug and result in prolonged coagulation. Following hip or lower extremity surgery, enoxaparin may be administered once daily for 7 to 10 days. Some orthopedic procedures such as repair of hip fractures require more prolonged therapy. Bleeding is the most serious adverse effect and the drug should not be administered to patients with active bleeding. The pentasaccharide unit is able to selectively inhibit Factor Xa without directly affecting thrombin. There is no specific antidote for overdose; administration of protamine is ineffective. Therapy is continued for 6 days, or until the patient has been switched to oral anticoagulation with warfarin. Two drugs in this class, ardeparin (Normiflo) and danaparoid (Orgaran), have been discontinued in the United States. Antithrombin (recombinant) and fondaparinux are parenteral anticoagulants that act by unique mechanisms. The drug is indicated for the prevention of perioperative and peripartum thromboembolic events in hereditary antithrombin-deficient patients. Levels of antithrombin activity in the blood must be monitored before, during, and immediately following therapy. The initial and subsequent drug doses are based on the level of antithrombin activity. It was reported that in at least one case, 1-mL heparin vials with 10,000 units/mL were placed in an automated dispensing unit where 10-unit/mL vials were usually kept. Warfarin (Coumadin) has been available as an anticoagulant for over 50 years and is the most frequently used drug in this class. Often, patients begin anticoagulation therapy with heparin and are switched to warfarin when their condition stabilizes. When transitioning, the two drugs must be administered concurrently for 2 to 3 days. Warfarin, on the other hand, takes 1 to 3 days of therapy to achieve optimum anticoagulation. Thus, concomitant pharmacotherapy is necessary to ensure continuous anticoagulation. During this transition, there is increased risk of bleeding, due to the additive anticoagulant action of the two drugs. The devices are expensive and the patient or their caregiver must be capable of understanding how to properly adjust the dosage. Ninety-nine percent of absorbed warfarin is bound to plasma proteins and is not immediately available to produce its effect. Dosage levels must be determined individually for each patient and carefully monitored. Patients stabilized on warfarin should not switch brands of the drug unless recommended by the health care provider, due to differences in bioavailability. Miscarriage Prevention and Low-Molecular-Weight Heparin Miscarriage in pregnancy is devastating, and recurrent miscarriage even more so. Recent research suggests that undiagnosed thrombophilia (a genetic hypercoagulability disorder) may play a role in some cases, but clots were also noted in the placenta after miscarriage in women without any confirmed genetic susceptibility for thrombophilia. Warfarin inhibits the synthesis of new clotting factors but does not affect clotting factors that are already circulating in the blood. It takes 3 to 4 days for the plasma levels of existing clotting factors to fall, and for the anticoagulant effect of warfarin to appear. Warfarin may release pieces of atheromatous plaque from vessel walls, resulting in systemic cholesterol microembolization that may occlude small vessels. For example, "purple-toe syndrome" is caused by cholesterol microembolization and severe cases may lead to gangrene or amputation. Long-term use of warfarin may increase the risk of osteoporosis and bone fractures. Patients should be instructed about prevention measures to minimize bleeding risk and to immediately notify health care providers of signs and symptoms of bleeding. A listing of selected drugs and supplements affecting warfarin therapy is given in Table 41. Herbal/Food: Herbal supplements such as green tea, ginkgo, feverfew, garlic, cranberry, chamomile, and ginger may increase the risk of bleeding. Lifespan and Diversity Considerations: Monitor older adults for bleeding more frequently because normal hepatic changes related to aging may prolong the action of the drug and increase the risk of bleeding. Patient and Family Education: Anticoagulants including warfarin carry a black box warning related to the increased risk of bleeding and hemorrhage. When possible, warfarin should be discontinued or the dosage lowered before dental or elective surgical procedures. Patients with heart failure may exhibit excessive anticoagulation with warfarin, which requires lower doses. Warfarin should not be taken during pregnancy because the drug has been shown to produce numerous fetal abnormalities, induce fatal bleeding, and can cause fetal death. Warfarin is believed to be safe for lactating women who are at risk for postpartum venous thrombus because very little of the drug enters breast milk. Because the therapeutic index of warfarin is very low, drugs that interact with warfarin have the potential to affect coagulation time and cause harm. Concurrent use with other drugs with anticoagulant activity, including aspirin, heparin, and antiplatelet drugs, may produce additive effects and excessive bleeding. The drug carries a black box warning that spinal or epidural hematomas may occur in anticoagulated patients receiving epidural or spinal anesthesia or who are undergoing spinal puncture. The direct thrombin inhibitors have an interesting history; they were originally derived from chemicals found in leeches. Leeches are wormlike animals that survive by sucking and digesting blood from mammals. Medical leeches are an ancient treatment that dates back to early Egyptian and Greek civilizations. They were applied to the skin as a type of bloodletting, which was thought to remove harmful substances from the body. Known as hirudotherapy, the use of leeches was largely discontinued with the advent of modern medicine in the early 1900s. However, leeches are still an approved therapy for relieving venous congestion in transplanted or reattached fingers or limbs. While studying leeches, scientists isolated a potent chemical called hirudin, which prevented blood from coagulating in the leech. The direct thrombin inhibitors bind reversibly to thrombin, preventing the formation of fibrin. Three drugs in the direct thrombin inhibitor class, lepirudin, bivalirudin, and desirudin, were derived from the hirudin molecule found in leeches and are structurally very similar. Argatroban and dabigatran inhibit thrombin but are not chemically related to the hirudin molecule. Patients with renal impairment should receive a dose reduction because the drug may accumulate and cause bleeding in these patients. Drug Interactions: Oral anticoagulants, including warfarin or heparin, may potentiate lepirudin activity. Drugs that inhibit platelet aggregation (such as aspirin, indomethacin, and ibuprofen) and thrombolytic drugs may induce bleeding. Herbal/Food: Herbal supplements that affect coagulation such as ginger, garlic, green tea, feverfew, or ginkgo may increase the risk of bleeding. Because of its relatively brief half-life, discontinuing the infusion results in an improvement in coagulation in a few hours. Lifespan and Diversity Considerations: Monitor older adults for bleeding more frequently because normal renal changes related to aging may prolong the action of the drug and increase the risk of bleeding. The same increased risk due to lessened renal clearance of the drug has also been noted in younger women. Patient and Family Education: Anticoagulants carry black box warnings related to the increased risk of bleeding and hemorrhage. Lepirudin (Refludan) Classification: Therapeutic: Anticoagulant Pharmacologic: Direct thrombin inhibitor Therapeutic Effects and Uses: Lepirudin is a protein that is nearly identical to hirudin, the natural substance isolated from leeches. Unlike lepirudin, which is excreted by the kidneys, argatroban is metabolized and eliminated by the liver and therefore may be used in patients with renal impairment. Caution must be observed, however, when administering the drug to patients with hepatic impairment.