MAO inhibitors are contraindicated since large quantities of catecholamines may be released, causing a sharp transient rise in blood pressure. MAO inhibitors should be withdrawn at least 14 days before treatment with reserpine. Likewise, reserpine must be withdrawn for a similar period of time prior to MAO inhibition. Reserpine should be used cautiously with digitalis and antiarrhythmic drugs as arrhythmias have occurred with rauwolfia preparations. Concurrent use of guanethidine and rauwolfia derivatives may cause bradycardia, mental depression and postural hypotension.
Reserpine diminishes the activity of levodopa.
Reserpine may potentiate the effect of adrenaline or other substances displaying sympathomimetic properties. Concurrent use of tricyclic antidepressants may increase the antihypertensive effects of reserpine. Impairment of consciousness may occur and may range from drowsiness to coma, depending upon the severity of overdosage. Lethargy, tiredness, apathy, confusion, agitation or depression may also ensue. Extrapyramidal disorders, headache, nausea, vomiting, increased intestinal motility and diarrhea, increased salivary and gastric secretion, and swelling of the nasal mucosa may also occur.