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Bactrim Dosage

Generic name: SULFAMETHOXAZOLE 800mg, TRIMETHOPRIM 160mg
Dosage form: tablet
Drug class: Sulfonamides

Medically reviewed by Drugs.com. Last updated on Jul 2, 2024.

BACTRIM is contraindicated in pediatric patients less than 2 months of age.

Urinary Tract Infections and Shigellosis in Adults and Pediatric Patients, and Acute Otitis Media in Children

Adults:The usual adult dosage in the treatment of urinary tract infections is 1 BACTRIM DS (double strength) tablet or 2 BACTRIM tablets every 12 hours for 10 to 14 days. An identical daily dosage is used for 5 days in the treatment of shigellosis.

Children:The recommended dose for children with urinary tract infections or acute otitis media is 40 mg/kg sulfamethoxazole and 8 mg/kg trimethoprim per 24 hours, given in two divided doses every 12 hours for 10 days. An identical daily dosage is used for 5 days in the treatment of shigellosis. The following table is a guideline for the attainment of this dosage:

Children 2 months of age or older:
Weight Dose–every 12 hours
lb kg Tablets

22

10

44

20

1

66

30

88

40

2 or 1 DS tablet

For Patients with Impaired Renal Function

When renal function is impaired, a reduced dosage should be employed using the following table:

Creatinine
Clearance (mL/min)
Recommended
Dosage Regimen

Above 30

Usual standard regimen

15–30

½ the usual regimen

Below 15

Use not recommended

Acute Exacerbations of Chronic Bronchitis in Adults
The usual adult dosage in the treatment of acute exacerbations of chronic bronchitis is 1 BACTRIM DS (double strength) tablet or 2 BACTRIM tablets every 12 hours for 14 days.

Pneumocystis jiroveciiPneumonia
Treatment

Adults and Children:
The recommended dosage for treatment of patients with documented Pneumocystis jiroveciipneumonia is 75 to 100 mg/kg sulfamethoxazole and 15 to 20 mg/kg trimethoprim per 24 hours given in equally divided doses every 6 hours for 14 to 21 days. 12The following table is a guideline for the upper limit of this dosage:

Weight

Dose–every 6 hours

lb

kg

Tablets

18

8

35

16

1

53

24

70

32

2 or 1 DS tablet

88

40

106

48

3 or 1½ DS tablets

141

64

4 or 2 DS tablets

176

80

5 or 2½ DS tablets

For the lower limit dose (75 mg/kg sulfamethoxazole and 15 mg/kg trimethoprim per 24 hours) administer 75% of the dose in the above table.

Prophylaxis
Adults:

The recommended dosage for prophylaxis in adults is 1 BACTRIM DS (double strength) tablet daily. 13

Children:
For children, the recommended dose is 750 mg/m 2/day sulfamethoxazole with 150 mg/m 2/day trimethoprim given orally in equally divided doses twice a day, on 3 consecutive days per week. The total daily dose should not exceed 1600 mg sulfamethoxazole and 320 mg trimethoprim. 14The following table is a guideline for the attainment of this dosage in children:

Body Surface Area Dose–every 12 hours
(m 2) Tablets

0.26

0.53

½

1.06

1

Traveler’s Diarrhea in Adults
For the treatment of traveler’s diarrhea, the usual adult dosage is 1 BACTRIM DS (double strength) tablet or 2 BACTRIM tablets every 12 hours for 5 days.

Frequently asked questions

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.