Substance abuse and hypertension are an important health concern, especially in adolescent and young adults presenting with elevated blood pressure and associated cardiovascular conditions. Illicit drugs including cocaine, marijuana, amphetamines, and methylenedioxymethamphetamine remain potential sources of acute or newly diagnosed hypertension. Cocaine is a powerful vasoconstrictor clearly related to hypertensive crises, myocardial infarction, arrhythmias, sudden death, strokes, and seizures, although not a definite cause of chronic hypertension. Potential therapies for cocaine induced hypertension and vasoconstriction include nitroglycerin, alpha-blockade combined alpha-à -blockade, and calcium channel blockers. The use of à -blockers alone should be avoided because of possible paradoxical rise in blood pressure including slight increases in systolic and diastolic blood pressure. Amphetamines and the newly abused 3,4-methylenedioxymethamphetamine are powerful sympathetic stimulants which may mimic the action of cocaine. Ecstasy, or 3,4-methylenedioxymethamphetamine, has additional severe psychiatric effects and should be considered in psychoses, panic disorders, and attempted suicide with new onset hypertension. The treatment approaches to 3,4-methylenedioxymethamphetamine toxicity needs further investigation. (c)2000 by Le Jacq Communications, Inc.