Bactrim
Bactrim (a combination of two antibiotics: sulfamethoxazole and trimethoprim) is a medication that’s used to treat an expansive list of bacterial infections, such as staph/MRSA. While Bactrim is safely prescribed for patients 2 months of age and older by dermatologists, the dosage needs to be carefully followed to ensure it’s long-term effectiveness for the patients. Below we’ve presented a helpful table for you to cross-reference dosage levels for your patients. Please note that administering Bactrim to newborns or infants younger than 2 months old is not advised due to the risk of serious side effects.
AVAILABLE AS: Trimethoprim/sulfamethoxazole Suspension (40/200 per 5mL)
(must be > 2 months old)
| WEIGHT | DOSE (for acute otitis media or UTI) | |
|---|---|---|
| (lbs) | (kg) | (10mg trimethoprim/kg/day) |
| 22 lbs | 10 kg | 5mL PO BID |
| 44 lbs | 20 kg | 10mL BID or 1 tab BID |
| 66 lbs | 30 kg | 15mL BID or 1.5 tab BID |
| 88 lbs | 40 kg | 20mL BID or 2 tab BID or 1 DS tab BID |
| Adult (skin infection; MRSA) | 1 DS tab PO BID ** (others will give 2 DS tab PO BID to obese patients) | |
**reference: personal communication with Dirk Elston, MD
1 tab = 80/400 (= 2 tsp of the suspension)
1 DS tab = 160/800 (= 4 tsp of the suspension)
High Dose Bactrim for treating PCP (as a point of reference)
| WEIGHT | DOSE – Every 6 Hours (= 20mg TMP/kg/day dose) | ||
|---|---|---|---|
| (lbs) | (kg) | Teaspoonfuls | Tablets |
| 18 lbs | 8 kg | 1 (5 mL) | |
| 35 lbs | 16 kg | 2 (10 mL) | 1 |
| 53 lbs | 24 kg | 3 (15 mL) | 1 1/2 |
| 70 lbs | 32 kg | 4 (20 mL) | 2 (or 1 DS Tablet) |
| 88 lbs | 40 kg | 5 (25 mL) | 2 1/2 |
| 106 lbs | 48 kg | 6 (30 mL) | 3 (or 1 1/2 DS Tablets) |
| 141 lbs | 64 kg | 8 (40 mL) | 4 (or 2 DS Tablets) |
| 176 lbs | 80 kg | 10 (50 mL) | 5 (or 2 1/2 DS Tablets) |
For the lower limit dose (15 mg/kg trimethoprim and 75 mg/kg sulfamethoxazole per 24 hours) administer 75% of the dose in the above table.
