藥劑部參考美國 Johns Hopkins 大學研究團隊所建立的 NxP (Nephrotoxic Potential) 專家共識分級清單，本品具「顯著以上腎毒性風險」，被認定具中度至高度腎損傷潛勢，特別是同時合併其他腎毒性藥物、脫水、高齡或既有腎功能異常的患者族群，應更加注意。

【藥品性質提示】 根據 2019 AGS Beers Criteria，本藥品為【潛在不適當用藥 (PIM)】，用於老年人時須謹慎使用；老年人 CrCl<15mL/min 時須避免使用。

Sulfonamides類抗生素 Treatment of urinary tract infections caused by susceptible strains of E. coli, Proteus, Klebsiella, Enterobacter, H. influenzae, S. pneumoniae, Shigella spp

Co-trimoxazole is a synergistic fixed combination of sulfamethoxazole (an intermediate-acting antibacterial sulfonamide), and trimethoprim; both sulfamethoxazole and trimethoprim are synthetic folate-antagonist anti-infectives.

1. Both trimethoprim and sulfamethoxazole are widely distributed into body tissues and and CSF; trimethoprim also distributes into bronchial secretions.
2. Trimethoprim and sulfamethoxazole have serum half-lives of approximately 8–11 and 10–13 hours, respectively (normal renal function). In adults with creatinine clearances of 10–30 and 0–10 mL/minute, serum half-life of trimethoprim may increase to 15 and greater than 26 hours, respectively.
3. In adults with chronic renal failure, sulfamethoxazole half-life may be 3 times that in patients with normal renal function. Trimethoprim serum half-lives of about 7.7 and 5.5 hours have been reported in children less than 1 year of age and between 1 and 10 years of age, respectively.

1. Pregnancy, infants younger than 2 months, lactation
2. Hypersensitivity to sulfonamides or trimethoprim, patients with impaired renal or hepatic function.

C

Probably safe, except in premature infant or infant with G6PD deficiency.

Agranulocytosis, aplastic and megaloblastic anemia, nausea, erythema multiforme, headache, mental depression

Dosage:
8-10 mg/kg/day of TMP and 40-50 mg/kg/day of SMZ, in 2-4 equally divided doses, every 6-12 hrs for 5 days for shigellosis and up to 14 day for severe UTI
Administration:
1. For all IV doses of cotrimoxazole, the drug in 100 ml of D5W per 5 ml vial over 30 minutes is recommended.
2. If fluid restriction is required, each 5ml ampule can be added to 75 ml D5W and should be administered within 2 hours.

1. CrCl> 30ml/min: 10-20mg/kg/day In 2-3 divided doses
2. CrCl 15-30ml/min: 5-10mg/kg/day In 2-3 divided doses
3. CrCl< 15ml/min Not recommended