Sulfamethoxazole and Trimethoprim



Bactrim™; Bactrim™ DS; Septra®; Septra® DS







Sulfamethoxazole and Trimethoprim

(sul fa meth OKS a zole & trye METH oh prim)

U.S. Brand Names
Bactrim™; Bactrim™ DS; Septra®; Septra® DS
Canadian Brand Names
Apo-Sulfatrim®; Novo-Trimel; Novo-Trimel D.S.; Nu-Cotrimox; Septra®; Septra® DS; Septra® Injection
Pharmacologic Category
Antibiotic, Sulfonamide Derivative; Antibiotic, Miscellaneous
Reasons not to take this medicine
  • Do not give this medicine to an infant younger than 2 months of age.
  • If you have an allergy to sulfamethoxazole, trimethoprim, or any other part of this medicine.
  • Tell healthcare provider if you are allergic to any medicine. Make sure to tell about the allergy and how it affected you. This includes telling about rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other symptoms involved.
  • If you have a sulfonamide (“sulfa”) allergy, talk with healthcare provider.
  • If you have any of the following conditions: Anemia because of lack of folic acid, liver disease, or porphyria.
  • If you are pregnant or may be pregnant.
  • If you are breast-feeding.
What is this medicine used for?
  • This medicine is used to treat a variety of bacterial infections.
How does it work?
  • Sulfamethoxazole and trimethoprim works to injure the bacteria and fight the infection.
How is it best taken?
  • To gain the most benefit, do not miss doses.
  • Use prescription as directed, even if feeling better.
  • Take this medicine with food.
  • Take this medicine with a full glass of water.
  • Drink plenty of noncaffeine-containing liquid unless told to drink less liquid by healthcare provider.
  • A liquid (suspension) is available if you cannot swallow pills. Shake well before use.
  • Those who have feeding tubes can also use the liquid. Flush the feeding tube before and after medicine is given.
What do I do if I miss a dose? (does not apply to patients in the hospital)
  • Take a missed dose as soon as possible.
  • If it is almost time for the next dose, skip the missed dose and return to your regular schedule.
  • Do not take a double dose or extra doses.
What are the precautions when taking this medicine?
  • If you are taking a blood thinner, you will require more frequent monitoring.
  • If you have kidney disease, talk with healthcare provider.
  • Check medicines with healthcare provider. This medicine may not mix well with other medicines.
  • Avoid alcohol (includes wine, beer, and liquor).
  • You can get sunburned more easily. Avoid sun, sunlamps, and tanning beds. Use sunscreen; wear protective clothing and eyewear.
  • Be careful if you have G6PD deficiency. Anemia may occur.
  • Use birth control that you can trust to prevent pregnancy while taking this medicine.
What are some possible side effects of this medicine?
  • Nausea or vomiting. Small frequent meals, frequent mouth care, sucking hard, sugar-free candy, or chewing sugar-free gum may help.
  • Not hungry.
  • Sunburn.
What should I monitor?
  • Change in condition being treated. Is it better, worse, or about the same?
  • If you are taking a blood thinner, check blood work (prothrombin time/INR). Talk with healthcare provider.
  • Take good care of your teeth. See a dentist regularly.
Reasons to call healthcare provider immediately
  • If you suspect an overdose, call your local poison control center immediately or dial 911.
  • Signs of a life-threatening reaction. These include wheezing; chest tightness; fever; itching; bad cough; blue skin color; fits; or swelling of face, lips, tongue, or throat.
  • Severe nausea or vomiting.
  • Yellow skin or eyes.
  • Any rash.
  • No improvement in condition or feeling worse.
How should I store this medicine?
  • Store at room temperature.
  • Protect from light.
  • Protect tablets from moisture. Do not store in a bathroom or kitchen.
General statements
  • If you have a life-threatening allergy, wear allergy identification at all times.
  • Do not share your medicine with others and do not take anyone else's medicine.
  • Keep all medicine out of the reach of children and pets.
  • Keep a list of all your medicines (prescription, natural products, supplements, vitamins, over-the-counter) with you. Give this list to healthcare provider (doctor, nurse, nurse practitioner, pharmacist, physician assistant).
  • Talk with healthcare provider before starting any new medicine, including over-the-counter, natural products, or vitamins.
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