What is Cotrimoxazole?

• Cotrimoxazole is an antibiotic that treats different types of bacterial infections. It fights bacteria in your body.
• Cotrimoxazole is used to treat infections such as urinary tract infections, bronchitis, ear infections (otitis), traveler's diarrhea, and Pneumocystis carinii pneumonia.
• Cotrimoxazole may also be used for purposes other than those listed in this medication guide.

What should I discuss with my doctor before taking Cotrimoxazole?

• Before taking this medication, tell your doctor if you have
  • kidney or liver disease, or
  • a glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency).
• You may not be able to take Cotrimoxazole, or you may require a lower dose or special monitoring during treatment if you have any of the conditions listed above.
• Cotrimoxazole is in the FDA pregnancy category C. This means that it is not known whether sulfamethoxazole and trimethoprim will harm an unborn baby. Do not take the medication without first talking to your doctor if you are pregnant.
• Cotrimoxazole passes into breast milk and may harm a nursing baby. Do not take it without first talking to your doctor if you are breast-feeding a baby.
• Cotrimoxazole is not approved for use in children younger than 2 months of age.

How should I take sulfamethoxazole and trimethoprim?

• Take this drug exactly as directed by your physician. If you do not understand these instructions, ask your pharmacist, nurse, or doctor to explain them to you.
• Take each dose with a full glass of water.
• Take it with food or milk if it upsets your stomach.
• You may crush the tablets and put them in water or a soft food like applesauce or pudding if you cannot swallow them whole.
• Take all of the Cotrimoxazole that has been prescribed for you even if you begin to feel better. Your symptoms may start to improve before the infections is completely treated.
• Store the tablets at room temperature away from moisture and heat.

What happens if I miss a dose?

• Take the missed dose as soon as you remember. However, if it is almost time for your next dose, skip the dose you missed and take only your next regularly scheduled dose. Do not take a double dose of this medication unless otherwise directed by your doctor.
• If you have only missed one dose, you can take the rest of your scheduled doses for that day at evenly spaced intervals.

What happens if I overdose?

• Seek emergency medical attention.
• Symptoms of a sulfamethoxazole and trimethoprim overdose include nausea, vomiting, decreased appetite, diarrhea, headache, yellowing of the skin or eyes, decreased urine production, bloody urine, and coma.

What should I avoid while taking sulfamethoxazole and trimethoprim?

• Avoid prolonged exposure to sunlight. Cotrimoxazole may increase the sensitivity of your skin to sunlight. Use a sunscreen and wear protective clothing when exposure to the sun is unavoidable.

What are the possible side effects of Cotrimoxazole?

• Stop taking the drug and seek emergency medical attention if you experience any of the following serious side effects:
  • an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives);
  • unusual bleeding or bruising; or
  • yellow skin or eyes.
• Other, less serious side effects may be more likely to occur. Continue to take your medication and talk to your doctor if you experience
  • headache, fatigue, or dizziness;
  • nausea, vomiting, decreased appetite, or diarrhea;
  • weakness; or
  • increased sensitivity to the sun.
• Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

What drug(s) may interact with cotrimoxazole?

• amiloride
• cyclosporine
• dapsone
• digoxin
• divalproex
• dofetilide
• doxercalciferol
• medicines for diabetes
• methenamine
• methotrexate
• metronidazole
• phenytoin
• potassium salts (potassium chloride, potassium phosphate)
• procainamide
• pyrimethamine
• rifampin
• some medicines used to treat blood pressure and/or heart failure (ACE inhibitors such as benazepril, enalapril, lisinopril, moexipril, quinapril, ramipril, and others)
• spironolactone
• sulfinpyrazone
• triamterene
• trimetrexate
• valproic acid
• warfarin