Lithiuminteractions

Diuretic-, ACE-, and ARB-induced sodium loss may increase serum lithium concentrations. Start with lower doses of lithium or reduce dosage, while frequently monitoring serum lithium concentrations and signs of lithium toxicity. See WARNINGS for additional caution information. Concomitant administration of lithium with serotonergic drugs can precipitate serotonin syndrome. Monitor patients for signs and symptoms of serotonin syndrome, particularly during lithium initiation. If serotonin syndrome occurs, consider discontinuation of lithium and/or concomitant serotonergic drugs. Examples of serotonergic drugs include selective serotonin reuptake inhibitors (SSRI), serotonin and norepinephrine reuptake inhibitors (SNRI), and monoamine oxidase inhibitors (MAOI). Concomitant administration of methyldopa, phenytoin, or carbamazepine with lithium may increase the risk of adverse reactions with these drugs. The following drugs can lower serum lithium concentrations by increasing urinary lithium excretion: acetazolamide, urea, xanthine preparations, and alkalinizing agents such as sodium bicarbonate. Concomitant extended use of iodide preparations, especially potassium iodide, with lithium may produce hypothyroidism. Concurrent use of calcium channel blocking agents with lithium may increase the risk of neurotoxicity in the form of ataxia, tremors, nausea, vomiting, diarrhea and/or tinnitus. Concurrent use of metronidazole with lithium may provoke lithium toxicity due to reduced renal clearance. Patients receiving such combined therapy should be monitored closely. Concurrent use of fluoxetine with lithium has resulted in both increased and decreased serum lithium concentrations. Patients receiving such combined therapy should be monitored closely. Nonsteroidal Anti-Inflammatory Drugs (NSAIDS): Lithium levels should be closely monitored when patients initiate or discontinue NSAID use. In some cases, lithium toxicity has resulted from interactions between an NSAID and lithium. Indomethacin and piroxicam have been reported to increase significantly steady-state plasma lithium concentrations. There is also evidence that other nonsteroidal anti-inflammatory agents, including the selective cyclooxygenase-2 (COX-2) inhibitors, have the same effect. In a study conducted in healthy subjects, mean steady-state lithium plasma levels increased approximately 17% in subjects receiving lithium 450 mg BID with celecoxib 200 mg BID as compared to subjects receiving lithium alone. Concomitant use of lithium with a Sodium-Glucose Cotransporter 2 (SGLT2) inhibitor may decrease serum lithium concentrations. Monitor serum lithium concentration more frequently during SGLT2 inhibitor initiation and dosage changes. Lithium may impair mental and/or physical abilities. Patients should be cautioned about activities requiring alertness (e.g., operating vehicles or machinery).