Drug-Induced Autonomic Dysfunction

Publisher Summary This chapter focuses on drug-induced autonomic dysfunction, providing examples of some offending medications, with extra attention given to nonantihypertensive agents. Although an identifiable secondary cause is present in ∼1–5% in the hypertensive population, drug-induced hypertension is often unrecognized or unreported. Patients rarely report recent cessation or intermittent use of a drug unless specifically asked, which becomes relevant due to withdrawal-related hypertension. Withdrawal from ethanol, opioids, benzodiazepines, or other drugs of abuse produces hyperadrenergic symptoms including tachycardia, sweating, and hypertension. Beta-blocker and clonidine withdrawal cause a syndrome with markedly elevated catecholamines and prominent hyperadrenergic symptoms, typically lasting for a few days. Drugs that cause hypertension via an off-target or unknown mechanism may be recognized after a medication has been marketed for many years. Although many drugs affect a single determinant of the blood pressure, a clinically evident change in blood pressure is normally blunted by compensatory responses. This is observed during treatment with vasodilator agents in the treatment of hypertension, which cause activation of sympathetic nervous system and the renin-angiotensin-aldosterone system.