Review of Clinically Important Drug Interactions with Lithium

Abstract

The therapeutic dosage of lithium is close to the toxic level, and drugs reducing the renal clearance of lithium can produce the most serious adverse effects. When used in combination with psychiatric drugs affecting mood, the therapeutic potential of lithium may be enhanced, and earlier concern regarding possible neurotoxic interactions with neuroleptics appear poorly substantiated. A number of specific interactions of low incidence have also been reported which should be borne in mind when new medications are introduced. The ready availability of lithium concentration monitoring in body fluids makes it possible to alter the effects of some potentially interactive drugs that may still need to be given in combination with lithium.

A new accurate method for predicting lithium clearance and daily dosage requirements in adult psychiatric patients

“…In addition, conditions that alter electrolyte balance may affect lithium levels in patients (11). Concomitant use of diuretics, angiotensinconverting enzyme inhibitors, calcium channel antagonists, or non-steroid anti-inflammatory drugs have been associated with lithium toxicity through pharmacokinetic interactions (14)(15)(16)(17). Concomitant medications with lithium may also contribute to the clinical manifestations of lithium toxicity since its clearance varies proportionally with glomerular filtration rate (GFR) and is usually 20-30% of GFR (12).…”

Drug‐Induced Lithium Toxicity in the Elderly: A Population‐Based Study

“…Elderly patients are at a particularly high risk of lithium toxicity because of altered pharmacokinetics, polypharmacy, renal impairment, and proneness to medication confusion 4,9–11 . Three major drug classes have been identified as potential precipitants of lithium toxicity 1,12 . Both diuretics, which promote renal sodium wasting, and angiotensin‐converting enzyme (ACE) inhibitors, which reduce glomerular perfusion pressure, can enhance the tubular reabsorption of lithium 13–20 .…”

Lithium Dosing Equations

“…Additionally, to increase applicability of the results, we included patients concomitantly taking drugs that could affect lithium clearance. [13][14][15] Supplemental analyses were conducted with patients on concomitant medications excluded from the sample. The findings of the relative accuracy of the equations were unchanged; however, medications with known lithium drug interactions were only used minimally by patients in the present sample.…”