Sulfamethoxazole-Trimethoprim Flashcards

Drug Information

• Sulfamethoxazole-Trimethoprim is classified as an antibacterial sulfonamide.
• It is categorized as Pregnancy Category D, indicating potential risks to the fetus.

Therapeutic Uses

• Effective in treating urinary tract infections (UTIs).
• Used for otitis media, bronchitis, and pneumonia.
• Treats Pneumocystis carinii infections and rheumatic fever.
• Can be applied in the management of burns.

Mode of Action

• Functions by inhibiting protein synthesis of nucleic acids.
• Exhibits a bactericidal effect, effectively killing bacteria.

Side Effects

• Common side effects include anorexia, nausea, vomiting, and diarrhea.
• May cause skin rash, stomatitis, fatigue, and depression.
• Neurological effects like headache, vertigo, and photosensitivity are also possible.

Adverse Reactions

• Life-threatening adverse reactions can occur, including leukopenia and thrombocytopenia.
• Risk of increased bone marrow depression, hemolytic anemia, aplastic anemia, and agranulocytosis.
• Severe skin reactions such as Stevens-Johnson syndrome and renal failure may arise.

Contraindications

• Not recommended for individuals with severe renal or hepatic disease.
• Contraindicated for patients with a known hypersensitivity to sulfonamides.

Drug Interactions

• Enhances the anticoagulant effect when used with warfarin.
• May amplify the hypoglycemic effect in conjunction with oral hypoglycemic drugs.

Lab Interactions

• Can lead to increased levels of BUN, serum creatinine, AST, ALT, and ALP in lab results.

Pharmacokinetics

• Well absorbed orally, with a protein binding range of 50-65%.
• Crosses the placenta, which is crucial for potential maternal-fetal risks.
• Half-life is approximately 8-12 hours, with excretion occurring in urine as metabolites.

Pharmacodynamics

• Oral administration onset occurs within 0.5-1 hour, reaching peak effect at 2-4 hours, while duration is undetermined.
• Intravenous administration has an immediate onset, with peak effect occurring within 0.5-1 hour, and duration remains undetermined.