Septra (Bactrim)

Other Brand Names - Bactrim

  • Type of Drug: Anti-infective.
  • Prescribed for: A wide variety of infections caused by susceptible organisms in many parts of the body, including urinary tract infections, bronchitis, and ear infections in children. It is also used to treat traveler’s diarrhea, Pneumocystis carinii infections in AIDS and leukemia patients, and prostate infections. Septra may be used to prevent urinary tract infections in women by taking the medicine immediately after intercourse. It may also be prescribed for cholera, nocardiosis, and Salmonella infections.

Septra (Bactrim) General Information

Septra is one of many combination products used to treat infections. It is unique because it interferes with the infecting micro-organism’s normal use of folic acid in two ways, making it more efficient than other antibacterial drugs. It is effective in many situations where other drugs are not-. Bacterial resistance to Septra develops more slowly than to either Sulfamethoxazole or Trimethoprim used alone.

Cautions and Warnings

Do not take Septra if you have a folic acid deficiency or are allergic to either ingredient or to any sulfa drug, antidiabetes drug, or thiazide-type diuretic. Septra should be used with caution by people with liver or kidney disease. Be sure to drink at least 1 full glass of water with each dose of Septra. Infants under 2 months of age should not be given this combination product.

Symptoms such as unusual bleeding or bruising, extreme tiredness, rash, sbre throat, fever, pallor, or yellowing of the skin or eyes may be early indications of a serious blood disorder. If any of these effects occur, contact your doctor immediately, and stop taking the drug. People taking Septra for Pneumocystis carinii infection also have compromised immune function. They may not respond to Septra and are more likely to develop less common drug side effects. Side effects are less severe in those taking Septra to prevent PCP. Septra should not be used for strep throat, because of a greater chance of treatment failure than with Penicillin.

Septra (Bactrim) Possible Side Effects

  • Most common: nausea, vomiting, upset stomach, loss of appetite, and skin rash or itching.
  • Less common: reduced levels of blood cells (red and white) and blood platelets (for blood clotting); allergic reactions (breathing difficulty, hives, etc.); drug fever; swelling around the eyes; arthritis-like pains; diarrhea; costing of the tongue; headache; tingling in the arms or legs; depression; convulsions; hallucinations; ringing in the ears; dizziness; difficulty sleeping; and feelings of apathy, tiredness, weakness, and nervousness. Septra may also affect your kidneys and cause you to produce less urine.

Septra (Bactrim) Drug Interactions

  • Septra may prolong the effects of anticoagulant (blood-thinning) agents (such as Warfarin) and oral antidiabetes drugs.
  • The Trimethoprim in Septra may increase the kidney toxicity and reduce the effectiveness of Cyclosporine.
  • The Sulfamethoxazole in Septra can increase the amount of Phenytoin and Methotrexate in the bloodstream, increasing the chance of drug-related side effects. Dosage reduction of the Phenytoin or Methotrexate may be needed to adjust for the presence of Septra.
  • Older adults taking a thiazide diuretic and Septra are more likely to develop reduced levels of blood platelets and an increased chance of bleeding under the skin.
  • Taking Septra together with Dapsone can result in increased blood levels of both drugs. Septra can interfere with the elimination of Zidovudine (AZT) through the kidneys, increasing the amount of AZT in the blood.

Septra (Bactrim) Food Interactions

Take each dose with a full glass of water. Continue to drink plenty of fluids throughout the day to decrease the risk of kidney-stone formation.

Usual Dose

Adult: 2 regular tablets or 1 Septra DS tablet every 12 hours for 5 to 14 days, depending on the condition being treated.
Child (2 months and older):
up to 22 pounds: 1 teaspoonful every 12 hours
23 to 44 pounds: 2 teaspoonfuls (or 1 tablet) every 12 hours
45 to 66 pounds: 3 teaspoonfuls (or ½ tablets) every 12 hours
67 to 88 pounds: 4 teaspoonfuls (or 2 tablets) every 12 hours

Septra (Bactrim) Overdosage

Small overdoses are not likely to cause harm. Larger overdoses can cause exaggerated drug side effects. Call your local poison control center or hospital emergency room for more information. ALWAYS bring the medicine bottle with you if you go for treatment.

Special Information

Take Septra exactly as prescribed for the full length of the prescription. Do not stop taking it just because you are beginning to feel better. Take each dose with a full glass of water, and drink plenty of fluids all day to lower the risk of kidney-stone formation.

Call your doctor if you develop sore throat, skin rash, or unusual bleeding or bruising, or any other persistent or intolerable drug side effect.

You may develop unusual sensitivity to bright light, particularly sunlight. If you have a history of light sensitivity or if you have sensitive skin, avoid prolonged exposure to sunlight while using Septra.

If you miss a dose of Septra, take it as soon as possible, if you take the medicine twice a day and it is almost time for your next dose, take 1 dose as soon as you remember and another in 5 to 6 hours, then go back to your regular schedule. If you take the medicine 3 or more times a day and it is almost time for your next dose, take 1 dose as soon as you remember and another in 2 to 4 hours, then continue with your regular schedule. Do not take any double doses.

Septra (Bactrim) Special Populations

Septra may affect folic acid in the developing fetus throughout pregnancy and should be used with caution. It should never be taken near the time you are ready to deliver because of the direct effect of one of the ingredients, Sulfamethoxazole, on the newborn, including yellowing of the skin or eyes. Talk to your doctor about Septra’s risks versus its benefits if the drug is to be used during pregnancy.
Premature infants, infants with too much bilirubin in their blood, and those who are deficient in the enzyme known as G-6-PD are more likely to develop problems with Septra. Septra is not recommended for use if you are nursing because of possible effects on the newborn infant.

Older adults are more likely to be sensitive to the effects of this drug, especially if they have liver or kidney problems. Severe skin reactions and decreased levels of blood platelets and red and white blood cells are the most common, especially when a thiazide diuretic is also being taken. Your doctor will reduce your Septra dose if you have kidney disease.