Tca adversa effects

Blockade of muscarinic receptors leads to blurred vision, xerostomia (dry mouth), urinary retention, sinus tachycardia, constipation, and aggravation of narrow-angle glaucoma. These agents also affect cardiac conduction similarly to quinidine, which may precipitate life-threatening arrhythmias should an overdose of one of these drugs be taken. The TCAs also block α-adrenergic receptors, causing orthostatic hypotension, dizziness, and reflex tachycardia. In clinical practice, this is the most serious problem in elderly adults. Imipramine is the most likely, and nortriptyline the least likely, to cause orthostatic hypotension. Sedation may be prominent, especially during the first several weeks of treatment, and is related to the ability of these drugs to block histamine H1 receptors. Weight gain is a common adverse effect of the TCAs. Sexual dysfunction, as evidenced by erectile dysfunction in men and anorgasmia in women, occurs in a significant minority of patients, but the incidence is still considered to be lower than the incidence of sexual dysfunction associated with the SSRIs. excessive sedation, lassitude, fatigue, and, occasionally, confusion; electrocardiogram (ECG) abnormalities, and cardiomyopathies tremor and paresthesias; and weight gain. Overdosage with tricyclics is extremely hazardous, and the ingestion of as little as a 2-week supply has been lethal. Manifestations include (1) agitation, delirium, neuromuscular irritability, convulsions, and coma; (2) respiratory depression and circulatory collapse; (3) hyperpyrexia; and (4) cardiac conduction defects and severe arrhythmias. The “3 Cs”—coma, convulsions, and cardiotoxicity— are characteristic.