Sertraline Does Not Alter Steady-State Concentrations or Renal Clearance of Lithium in Healthy Volunteers

An open-label, placebo-controlled study was conducted to determine the effects of sertraline on the steady-state levels and renal clearance of lithium in 20 healthy volunteers. Subjects received 600 mg of lithium twice daily for 9 days. On the evening of day 8, subjects received orally either placebo or 100 mg of sertraline; these were administered twice, 8 hours apart, beginning 2 hours after the evening dose of lithium. In a comparison of day 8 with day 9 (before administration of the morning doses of lithium), sertraline was associated with only a 0.01 mEq/L (1.4%) decrease in steady-state levels and a 0.11 L/hour (6.9%) increase in the renal clearance of lithium. Neither change was statistically significant relative to placebo. Four subjects were excluded from analysis because of protocol violations or laboratory abnormalities unrelated to sertraline. Seven subjects who received lithium plus sertraline experienced side effects, mainly tremors, possibly related to treatment, whereas none of those administered lithium plus placebo experienced side effects. No sertraline-related laboratory abnormalities were observed.