Antihypertensive drugs adverse effects

Altered homeostasis in older persons can lead to important and common adverse drug effects the less robust homeostatic milieu may be stressed by drugs, causing adverse effects. Examples include orthostatic hypotension due to antihypertensives and other agents that cause a-adrenergic blockade (e.g. terazosin, doxazosin, tricyclic antidepressants and phenothiazines) in those with barorecep-tor dysfunction. Diuretics can cause hyponatraemia or hypokalaemia in older patients, whereas ACE inhibitors and NSAIDs can cause hyperkalaemia. 

Compared with previously available therapy, the adverse effects associated with cyclosporine are much less severe but still worthy of concern. Nephrotoxicity, which can occur in up to 75% of patients, ranges from severe tubular necrosis to chronic interstitial nephropathy. This effect is generally reversible with dosage reduction. Vasoconstriction appears to be an important aspect of cyclosporine-induced nephrotoxicity. Hypertension occurs in 25% of the patients and more frequently in patients with some degree of renal dysfunction the concomitant use of antihypertensive drugs may prove useful. Hyperglycemia, hyperlipidemia, transient liver dysfunction, and unwanted hair growth are also observed. 

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. 

Practolol (Fig. 7.79) is an antihypertensive drug, which had to be withdrawn from general use because of severe adverse effects that became apparent in 1974, about four years after the drug had been marketed. The toxicity of practolol was unexpected, and when it occurred, it was severe. Furthermore, it has never been reproduced in experimental animals, even with the benefit of hindsight. 

As might be expected, ganglionic blockers produce a multitude of side effects because of the inhibition of both sympathetic and parasympathetic responses. Some adverse effects include gastrointestinal discomfort (nausea, constipation), urinary retention, visual disturbances, and orthostatic hypotension. At higher doses, they may even exhibit some neuromuscular blocking activity. These and other side effects may be quite severe in some patients. Fortunately, ganglionic blockers are usually not used for extended periods because the patient is placed on other antihypertensive drugs when the hypertensive crisis is resolved. 

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. 

In the worst-case scenario, maximizing those lifestyle modifications and adding the blood pressure-lowering supplements would still have tremendous benefits even if I had to take one of those drugs. Simply enough, I would be able to minimize the dosage needed and thus limit the potential side effects and adverse reactions that universally accompany antihypertensive drugs. 

Anorectic drugs act mainly on the satiety centre in the hypothalamus (1). They also have metabohc effects involving fat and carbohydrate metaboUsm. Most of them are structurally related to amfetamine and increase physical activity. Their therapeutic effect tends to abate after some months, and part of this reduction in effect may be due to chemical alterations in the brain. Fenfluramine commonly produces drowsiness in normal doses, but has stimulaut effects in overdosage. Dexamfetamine, phenmetrazine, and benzfetamine all tend to cause euphoria, with a risk of addiction. Euphoria occasionally occurs with amfepramone (diethylpropion), phentermine, and chlorphentermine, but to a much lesser extent. Some adverse effects are due to sympathetic stimulation and gastrointestinal irritation these may necessitate withdrawal but are never serious. There are interactions with monoamine oxidase inhibitors and antihypertensive drugs. 

---