Antihypertensive medications

Depending upon the location and severity of the stroke at admission, patients may have cardiac and/or respiratory instability at the time of presentation to the emergency department (ED). They may need to be stabilized hemodynamically or intubated for airway protection or respiratory distress. Blood pressure management is often a crucial management issue, and the use of vasopressor or antihypertensive medications is common. In stroke patients at risk for malignant cerebral... 

Signs Patient has previous blood pressure measurements indicating SBP greater than 130 or DBP greater than 80 mm Hg in clinic, or is currently taking antihypertensive medication(s). 

Disulfiram works by irreversibly blocking the enzyme aldehyde dehydrogenase, a step in the metabolism of alcohol, resulting in increased blood levels of the toxic metabolite acetaldehyde. As levels of acetaldehyde increase, the patient experiences decreased blood pressure, increased heart rate, chest pain, palpitations, dizziness, flushing, sweating, weakness, nausea and vomiting, headache, shortness of breath, blurred vision, and syncope. These effects are commonly referred to as the disulfiram-ethanol reaction. Their severity increases with the amount of alcohol that is consumed, and they may warrant emergency treatment. Disulfiram is contraindicated in patients who have cardiovascular or cerebrovascular disease, because the hypotensive effects of the disulfiram-alcohol reaction could be fatal in such patients or in combination with antihypertensive medications. Disulfiram is relatively contraindicated in patients with diabetes, hypothyroidism, epilepsy, liver disease, and kidney disease as well as impulsively suicidal patients. 

Although tacrolimus therapy is associated with increasing blood pressure, studies have found that tacrolimus has less dramatic effects on GFR and RBF than cyclosporine. In some clinical trials, tacrolimus caused less severe HTN and required significantly fewer antihypertensive medications at both 24 and 60 months after transplantation than cyclosporine.61-63 Thus conversion from cyclosporine-based immunosuppression to tacrolimus-based immunosuppression may be one way to minimize blood pressure increases in transplant recipients. Conversion to sirolimus also may be an alternative to the calcineurin inhibitors in patients with difficult-to-treat HTN because sirolimus therapy is less associated with increased blood pressure. Additionally, withdrawal or tapering of steroid therapy may be an effective strategy for lowering blood pressure. 

In order to achieve a goal blood pressure, lifestyle modifications, including diet, exercise, sodium restriction, and smoking cessation, are recommended.63 Unfortunately, lifestyle modifications alone often are inadequate to control HTN in this high-risk population, and antihypertensive medications usually are needed. 

Discontinue antihypertensive medications IV fluids to maintain systolic blood pressure greater than 80-90 mm Hg or vasopressor support with an a-agonist such as phenylephrine as indicated. 

The decrease in the ability of the aging body to respond to baroreflexive stimuli can result in very serious consequences for elderly patients [115-117]. Because of this decrease in sensitivity and the decreased cardiac output witnessed in elderly patients, they are predisposed to the effects of orthostatic hypotension that can occur when one is taking antihypertensive medication (e.g., prazosin). Indeed, the fact that elderly persons are prone to accidental falls may be due to this change in sensitivity [115-117]. 

Clonidine (Catapres). Clonidine, an antihypertensive medication that decreases serotonin availability through a mechanism distinct from cyproheptadine, has also been tested in the treatment of AN. Unfortunately, clonidine does not appear to promote weight gain in anorexia patients. In addition, clonidine may further exacerbate the low blood pressure that AN patients commonly experience. Consequently, clonidine has no role in the treatment of AN. 

To circumvent problems, encourage patient compliance, avoid excessive doses, avoid combining sympatholytics and -blockers, and maintain antihypertensive medication in surgical patients. When discontinuing medication, taper the dose slowly, one drug at a time use special caution in patients with coronary artery or cerebrovascular disease. 

Methylphenidate may decrease therapeutic effects of concomitantly administered antihypertensive medications and may potentiate effects of warfarin, phenytoin, phenylbutazone, and tricyclic antidepressants. When methylphenidate and MAOIs are coadministered, hypertensive crisis may result. 

Despite the large number of patients with chronic hypertension, hypertensive emergencies are relatively rare. Marked or sudden elevation of blood pressure may be a serious threat to life, however, and prompt control of blood pressure is indicated. Most frequently, hypertensive emergencies occur in patients whose hypertension is severe and poorly controlled and in those who suddenly discontinue antihypertensive medications. 

Melatonin appears to be well tolerated and is often used in preference to over-the-counter "sleep-aid" drugs. Although melatonin is associated with few adverse effects, some next-day drowsiness has been reported as well as fatigue, dizziness, headache, and irritability. Melatonin may affect blood pressure as both increases and decreases in blood pressure have been observed. Careful monitoring is recommended, particularly in patients initiating melatonin therapy while taking antihypertensive medications. 

Powers, R. L., K. A. Halbritter, J. G. Arbogast, J. L. Neely, and A. J. Williams. 1998. Do Interactions with Pharmaceutical Representatives Influence Antihypertensive Medication Prescribing Practices of Family Medicine and General Internal Medicine Physicians Journal of General Internal Medicine 13, Supplement 13. 

Dependence is a term that is not frequently used outside of psychopharmacology but in fact is a key feature of many antihypertensive medications, hormones, and other treatments throughout medicine. Thus, several antihypertensives can produce rebound hypertension, worse than the original blood pressure elevation, when sud-... 

Reserpine is a neuroleptic and an antihypertensive medication obtained from Rauwolfia... 

In alleviating symptoms, drugs may also induce adverse effects, which may or may not be acceptable to patients. For example, numerous agents with anticholinergic properties cause dry mouth, which is easily correctable and hence is acceptable to patients. Conversely, some antihypertensive medications cause impotence in male patients, which they may find unacceptable, and this side effect may thus lead to lack of compliance with the prescribed medication. 

Hypertension (>140/90 mm Hg on multiple measurements on several occasions), or currently taking antihypertensive medications... 

Beers MH, Passman LJ (1990) Antihypertensive medications and depression. Drugs 40 792-799. 

Cushman WC, Reda DJ, Perry HM, Williams D, Abdellatif M, Materson BJ. Regional and racial differences in response to antihypertensive medication use in a randomized controlled trial of men with hypertension in the United States. Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents. Arch Intern Med 2000 160 825-831. 

Next, the doctor began to address the patient s uncontrolled hypertension. Believing him to be reasonably dependable and compliant with his diuretic therapy, the doctor realized that the patient s current hypertension medication was not working. Instead of increasing the dose of hydrochlorothiazide, he felt that the patient would benefit from an additional antihypertensive medication in combination with his present therapy. 

Question A.31 Which additional antihypertensive medication will most benefit the patient ... 

Although variations have been identified in the antihypertensive effects (efficacy and duration of action) of different ARBs, the results are conflicting, and hence no definitive conclusion can be drawn on the superiority of one ARB over any other. Special features of the drug (e.g., the uricosuric effect of losartan) may be important in selected patients. Differences in safety and side-effect profile are nil or minimal among the different agents, with all ARBs being extremely well tolerated as compared to other classes of antihypertensive medications. 

Q9 Sodium nitroprusside can be used to rapidly reduce BP in hypertensive emergencies, but it is not suitable as a regular antihypertensive medication. Why is this ... 

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