Bactrim, an antibacterial combination drug, is prescribed for the treatment of certain urinary tract infections, severe middle ear infections in children, long-lasting or frequently recurring bronchitis in adults that has increased in seriousness, inflammation of the intestine due to a severe bacterial infection, and travelers' diarrhea in adults. Bactrim is also prescribed for the treatment of Pneumocystis carinii pneumonia, and for prevention of this type of pneumonia in people with weakened immune systems.
Sulfamethoxazole, an ingredient in Bactrim, is one of a group of drugs called sulfonamides, which prevent the growth of bacteria in the body. Rare but sometimes fatal reactions have occurred with use of sulfonamides. These reactions include Stevens-Johnson syndrome (severe eruptions around the mouth, anus, or eyes), progressive disintegration of the outer layer of the skin, sudden and severe liver damage, a severe blood disorder (agranulocytosis), and a lack of red and white blood cells because of a bone marrow disorder.
Notify your doctor at the first sign of an adverse reaction such as skin rash, sore throat, fever, joint pain, cough, shortness of breath, abnormal skin paleness, reddish or purplish skin spots, or yellowing of the skin or whites of the eyes.
Frequent blood counts by a doctor are recommended for patients taking sulfonamide drugs.
- vomiting;
- skin rash;
- nausea;
- lack or loss of appetite;
- hives;
Recommended dosage
ADULTS
Urinary Tract Infections and Intestinal Inflammation
The usual adult dosage in the treatment of urinary tract infection is 1 Bactrim DS (double strength tablet) or 2 Bactrim tablets, or 4 teaspoonfuls (20 ml) of Bactrim Pediatric Suspension every 12 hours for 10 to 14 days. The dosage for inflammation of the intestine is the same but is taken for 5 days.
Worsening of Chronic Bronchitis
The usual recommended dosage is 1 Bactrim DS (double strength tablet), 2 Bactrim tablets, or 4 teaspoonfuls (20 ml) of Bactrim Pediatric Suspension every 12 hours for 14 days.
Treatment of Pneumocystis Carinii Pneumonia
The recommended dosage is 15 to 20 mg of trimethoprim and 75 to 100 mg of sulfamethoxazole per 2.2 pounds of body weight per 24 hours divided into equal doses every 6 hours for 14 to 21 days.
Prevention of Pneumocystis Carinii Pneumonia
The recommended dosage is 1 Bactrim DS (double strength tablet) once daily.
Travelers' Diarrhea
The usual recommended dosage is 1 Bactrim DS (double strength tablet), 2 Bactrim tablets, or 4 teaspoonfuls (20 ml) of Bactrim Pediatric Suspension every 12 hours for 5 days.
CHILDREN
Urinary Tract Infections or Middle Ear Infections
The recommended dosage for children 2 months of age or older, given every 12 hours for 10 days, is determined by weight. The following table is a guideline for this dosage:
22 pounds, 1 teaspoonful (5 ml)
44 pounds, 2 teaspoonfuls (10 ml) or 1 tablet
66 pounds, 3 teaspoonfuls (15 ml) or one-and-a-half tablets
88 pounds, 4 teaspoonfuls (20 ml) or 2 tablets or 1 DS tablet
Intestinal Inflammation
The recommended dosage is identical to the dosage recommended for urinary tract and middle ear infections; however, it should be taken for 5 days.
Treatment of Pneumocystis Carinii Pneumonia
The recommended dosage, taken every 6 hours for 14 to 21 days, is determined by weight. The following table is a guideline for this dosage:
18 pounds, 1 teaspoonful (5 ml)
35 pounds, 2 teaspoonfuls (10 ml) or 1 tablet
53 pounds, 3 teaspoonfuls (15 ml) or one-and-a-half tablets
70 pounds, 4 teaspoonfuls (20 ml) or 2 tablets or 1 DS tablet
Prevention of Pneumocystis Carinii Pneumonia
The recommended dosage, taken twice a day, on 3 consecutive days per week, is determined by body surface area. The total daily dose should not exceed 320 mg trimethoprim and 1600 mg sulfamethoxazole.
The safety of repeated use of Bactrim in children under 2 years of age has not been established.
OLDER ADULTS
There may be an increased risk of severe side effects when Bactrim is taken by older people, especially in those who have impaired kidney and/or liver function or who are taking other medication. Consult with your doctor before taking Bactrim.
