Stabilization of high blood pressure with tricyclic antidepressants and lithium combinations in hypertensive patients.

Combinations of tricyclic antidepressant drugs and lithium have been used for certain types of depression. This combination of drugs has a tendency to stabilize or decrease high blood pressure among patients with hypertension, and we have observed such a phenomenon among five patients. In four patients, difficulty was encountered in withdrawing the tricyclic agent because of exacerbation of hypertension. The time required to stabilize blood pressure varied from a few days to a few weeks. Withdrawal of antihypertensive medication was possible after initiation of combination therapy with lithium and tricyclic agents in three patients. A hypothesis for the mechanism of this interesting observation is offered.