Trimethoprime-sulfamethoxazole (TMP-SMX)
Identification
Brand Names
- Septra
- Bactrim (US)
- TMP-SMX
Dosing
Based on the trimethroprim component.
| Form
|
TMP
|
SMX
|
| Suspension
|
8 mg/ml
|
40 mg/ml
|
| Injection
|
16 mg/ml
|
80 mg/ml
|
| SS tab
|
80 mg
|
400 mg
|
| DS tab
|
160 mg
|
800 mg
|
Conversion: 2 SS tabs = 1 DS tab = 20 mL oral suspension = 10 mL IV
Oral Dosing
- Ranges from 1 SS tab BID (160 mg TMP TDD) to 3 DS tabs TID (1440 mg TMP TDD)
Intravenous Dosing
- 10 to 20 mg/kg TMP total daily dose, split TID to QID
TMP 10 mg/kg per day
| Weight (kg)
|
Dose (IV)
|
Total dose TMP (mg/day)
|
| 40-49
|
10 mL q8h
|
480
|
| 50-64
|
10 mL q6h
|
640
|
| 65-74
|
15 mL q8h
|
720
|
| 75-99
|
15 mL q6h
|
960
|
| 100-129
|
20 mL q6h
|
1280
|
TMP 15 mg/kg per day
| Weight (kg)
|
Dose (IV)
|
Total dose TMP (mg/day)
|
| 40-44
|
10 mL q6h
|
640
|
| 45-49
|
15 mL q8h
|
720
|
| 50-69
|
15 mL q6h
|
960
|
| 70-79
|
25 mL q8h
|
1200
|
| 80-89
|
20 mL q6h
|
1280
|
| 90-99
|
30 mL q8h
|
1440
|
| 100-109
|
25 mL q6h
|
1600
|
| 110-119
|
35 mL q8h
|
1680
|
| 120-129
|
30 mL q6h
|
1920
|
TMP 20 mg/kg per day
| Weight (kg)
|
Dose (IV)
|
Total dose TMP (mg/day)
|
| 40-54
|
15 mL q6h
|
960
|
| 55-69
|
20 mL q6h
|
1280
|
| 70-79
|
30 mL q8h
|
1440
|
| 80-89
|
25 mL q6h
|
1600
|
| 90-104
|
30 mL q6h
|
1920
|
| 105-119
|
35 mL q6h
|
2240
|
| 120-134
|
40 mL q6h
|
2560
|
Renal Dosing
| CrCl (mL/min)
|
Bacterial infection (TMP)
|
PJP (TMP)
|
| > 30
|
8-12 mg/kg/day in 2-4 divided doses
|
15-20 mg/kg/day in 2-4 divided doses
|
| 10 to 29
|
75% of usual dose
|
12-15 mg/kg/day in 2-4 divided doses
|
| < 10, including PD
|
Generally not recommended; use 50% of usual dose
|
Generally not recommended; use 7.5-10 mg/kg/day in 2-4 divided doses
|
| Hemodialysis
|
50% of usual dose, scheduled post-dialysis
|
50% of usual dose, scheduled post-dialysis
|
| CRRT
|
7.5 mg/kg/day in 2-4 divided doses
|
15 mg/kg/day in 2-4 divided doses
|
Notable Side Effects
- Allergic reactions, including anaphylaxis and a relatively high rate of SJS/TEN
- GI upset, including nausea at higher doses
- Interactions
- Increases warfarin levels
- Anemia, neutropenia and thrombocytopenia
- It is a mild folate antagonist
- Hepatotoxicity
- Hyperkalemia
- Hypoglycemia
- Acute kidney injury, though it also increases tubular creatinine reabsorption
- Renal tubular acidosis
Further Reading
