In patients with which preexisting condition can Trimethoprim-Sulfamethoxazole cause hemolytic anemia?

Trimethoprim-Sulfamethoxazole can cause hemolytic anemia in patients with G6PD deficiency due to the role of glucose-6-phosphate dehydrogenase in protecting red blood cells from oxidative stress. G6PD is an enzyme that helps maintain the levels of glutathione, a powerful antioxidant. In individuals with a deficiency of this enzyme, the red blood cells are more susceptible to oxidative damage.

Trimethoprim-Sulfamethoxazole, as a sulfonamide antibiotic, can induce oxidative stress which can lead to the destruction of red blood cells in patients with G6PD deficiency, resulting in hemolytic anemia. This reaction is an important consideration when prescribing this antibiotic, as understanding the patient's underlying conditions can help prevent adverse effects.

Other conditions such as renal failure, diabetes mellitus, and liver disease may affect the pharmacokinetics or efficacy of medications but are not directly related to the mechanism that leads to hemolytic anemia caused by oxidative stress from medications like Trimethoprim-Sulfamethoxazole.