What is the effect of sulindac when used with lithium?

Using sulindac in conjunction with lithium can lead to increased lithium levels in the bloodstream. This interaction occurs because sulindac, a nonsteroidal anti-inflammatory drug (NSAID), can reduce renal clearance of lithium. Normally, the kidneys filter and excrete lithium, but when sulindac is introduced, it can impair this process. As a result, lithium remains in the system for a longer duration, leading to higher serum levels.

It is important to monitor lithium levels closely when a patient is prescribed sulindac, as elevated lithium levels can increase the risk of toxicity, manifesting in symptoms such as tremors, confusion, and other neuropsychiatric effects. Therefore, the correct understanding of this drug interaction emphasizes the need for careful management of lithium therapy, especially in patients requiring anti-inflammatory treatment with sulindac.