DOSAGE AND ADMINISTRATION

Sulfamethoxazole and trimethoprim 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 sulfamethoxazole and trimethoprim double strength tablet or 2 sulfamethoxazole and trimethoprim 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	1½
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 to 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 sulfamethoxazole and trimethoprim double strength tablet, or 2 sulfamethoxazole and trimethoprim tablets every 12 hours for 14 days.

Pneumocystis jirovecii** Pneumonia**

Treatment

Adults and Children:

The recommended dosage for treatment of patients with documented Pneumocystis jirovecii pneumonia 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 days12. The 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	1 ½
70	32	2 or 1 DS tablet
88	40	2 ½
106	48	3 or 1 ½ DS tablets
141	64	4 or 2 DS tablets
176	80	5 or 2 ½ 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 sulfamethoxazole and trimethoprim double strength tablet daily13.

Children:

For children, the recommended dose is 750 mg/m2/day sulfamethoxazole with 150 mg/m2/day trimethoprim given orally in equally divided doses twice a day, on 3 consecutive days per week. The total daily dose should not exceed 1,600 mg sulfamethoxazole and 320 mg trimethoprim14. The following table is a guideline for the attainment of this dosage in children:

Body Surface Area	Dose – every 12 hours
(m2)	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 sulfamethoxazole and trimethoprim double strength tablet or 2 sulfamethoxazole and trimethoprim tablets every 12 hours for 5 days.