Which medication interaction increases citalopram exposure?

Proton pump inhibitors (PPIs) are known to interact with various medications, including citalopram. The correct answer highlights that the use of PPIs can increase the exposure of citalopram in the body. This occurs due to the way these medications affect gastric pH levels and, consequently, the absorption and metabolism of citalopram.

Citalopram is primarily metabolized by the liver enzymes of the cytochrome P450 family, particularly CYP2C19, and to some extent, CYP3A4. When proton pump inhibitors are taken, they can raise the pH in the stomach, which may modify the solubility and absorption characteristics of some drugs, including citalopram, resulting in higher plasma concentrations.

Increased exposure to citalopram can elevate the risks of citalopram's side effects, such as QT interval prolongation, particularly in susceptible populations. Therefore, careful monitoring and adjustment of citalopram dosage may be necessary when a patient is concurrently taking a proton pump inhibitor to avoid potential adverse effects brought about by the interaction.

Other medications, like ranolazine, calcium channel blockers, and beta-blockers, do not have a significant impact on the levels of c