lithium and lisinopril

Lisinopril reduces aldosterone secretion, leading to increased renal sodium and water loss. This depletes extracellular volume, which increases proximal tubular reabsorption of lithium. The net effect is a reduction in lithium clearance and a rise in serum lithium concentrations. Additionally, ACE inhibitors can impair renal function, further decreasing lithium excretion.

Patients may develop signs of lithium toxicity, including nausea, vomiting, diarrhoea, fine tremor, ataxia, confusion, and in severe cases seizures and coma. The onset is usually gradual over days to weeks but can be more rapid if renal function deteriorates. Lithium levels should be monitored; toxicity can occur even with therapeutic doses if renal function is compromised.

Avoid co-prescription where possible. If an ACE inhibitor is necessary, consider an alternative antihypertensive. If combined, use the lowest effective doses, monitor serum lithium levels and renal function at baseline, after any dose change, and at least weekly for the first few weeks, then less frequently. Patients should be advised to seek immediate medical attention if symptoms of lithium toxicity occur.

Well established. The interaction is documented in multiple sources, including the British National Formulary and product monographs. Case reports and pharmacokinetic studies consistently show increased lithium levels with ACE inhibitors. Monitoring is recommended in clinical practice guidelines.