Sinus or supraventricular tachycardia Albuterol Amphetamines Antidepressants Antihistamines Caffeine Cocaine Ephedra Energy drinks Ephedrine, pseudoephedrine Hallucinogens (e.g., lysergic acid diethylamide [LSD] or phencyclidine [PCP]) Herbal stimulants Marijuana Methcathinones (bath salts) and khat (Catha edulis leaves, popular in Africa and the Middle East) Phenothiazines Synthetic cannabinoids (e.g., K2 or Spice) Tobacco Ventricular tachycardia or torsades de pointes Amphetamines Antiarrhythmic agents (e.g., quinidine, procainamide, mexiletine, flecainide, encainide) Arsenic Caffeine Chloral hydrate Chlorinated hydrocarbons Chloroquine Cocaine Digoxin Organophosphate pesticides Phenothiazines Tricyclic antidepressants