Bactrim is the brand name of a combination medicine that contains the antibiotics sulfamethoxazole and trimethoprim.

It’s used to treat certain bacterial infections, including ear infections, bronchitis, pneumonia, urinary tract infections (UTIs), intestinal infections, and others. Bactrim is sometimes also given to treat traveler’s diarrhea.

This medicine is in a class of drugs called sulfonamides. It works by halting the growth of bacteria.

The U.S. Food and Drug Administration (FDA) first approved Bactrim in 1973.

warnings

What is the most important information I should know about Bactrim (Sulfamethoxazole and Trimethoprim Oral/Injection)?

You should not use this medicine if you are allergic to sulfamethoxazole or trimethoprim, or if you have:

May cause birth defects. Do not use if you are pregnant. Tell your doctor if you become pregnant.

Do not breastfeed.

This medicine should not be given to a child younger than 2 months old.

severe liver disease;
kidney disease that is not being treated or monitored;
anemia (low red blood cells) caused by folic acid deficiency;
a history of low blood platelets after taking trimethoprim or any sulfa drug; or
if you take dofetilide.

kidney or liver disease;
a folate (folic acid) deficiency;
asthma or severe allergies;
HIV or AIDS;
a thyroid disorder;
malnourishment;
alcoholism;
an electrolyte imbalance (such as low blood sodium or high potassium);
porphyria, or glucose-6-phosphate dehydrogenase (G6PD) deficiency; or
if you use a blood thinner (such as warfarin) and you have routine "INR" or prothrombin time tests.

Tell your doctor if you have ever had:

Side Effects

What are the side effects of Bactrim (Sulfamethoxazole and Trimethoprim Oral/Injection)?

Get emergency medical help if you have (hives, cough, chest pain, shortness of breath, swelling in your face or throat) (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling). signs of an allergic reactionor a severe skin reaction

Seek medical treatment if you have a serious drug reaction that can affect many parts of your body. Symptoms may include: skin rash, fever, swollen glands, joint pain, muscle aches, severe weakness, pale skin, unusual bruising, or yellowing of your skin or eyes.

Call your doctor at once if you have:

severe stomach pain, diarrhea that is watery or bloody (even if it occurs months after your last dose);
any skin rash, no matter how mild;
yellowing of your skin or eyes;
a seizure;
new or unusual joint pain;
increased or decreased urination;
swelling, bruising, or irritation around the IV needle;
increased thirst, dry mouth, fruity breath odor;
new or worsening cough, fever, trouble breathing;
high blood potassium--nausea, weakness, tingly feeling, chest pain, irregular heartbeats, loss of movement;
low blood sodium--headache, confusion, problems with thinking or memory, weakness, feeling unsteady; or
low blood cell counts--fever, chills, mouth sores, skin sores, easy bruising, unusual bleeding, pale skin, cold hands and feet, feeling light-headed or short of breath.

nausea, vomiting, loss of appetite; or
skin rash.

Common side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Interactions

What drugs and food should I avoid while taking Bactrim (Sulfamethoxazole and Trimethoprim Oral/Injection)?

If you use the injection form of this medicine, do not eat or drink anything that contains propylene glycol (an ingredient in many processed foods, soft drinks, and medicines). Dangerous effects could occur.

Sulfamethoxazole and trimethoprim could make you sunburn more easily. Avoid sunlight or tanning beds. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

Dosage Guidelines & Tips

How to take Bactrim (Sulfamethoxazole and Trimethoprim Oral/Injection)?

Use Bactrim (Sulfamethoxazole and Trimethoprim Oral/Injection) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Sulfamethoxazole and trimethoprim is taken by mouth. oral

Sulfamethoxazole and trimethoprim is given in a vein. Be sure you understand how to properly mix this medicine with a liquid (diluent) and how to store the mixture. Ask your doctor or pharmacist if you don't understand how to use an injection. injection

Prepare an injection only when you are ready to give it. Call your pharmacist if the medicine looks cloudy, has changed colors, or has particles in it.

Mixed medicine must be used within 2 to 6 hours depending on the amount of diluent in the mixture. Follow your doctor's instructions. Do not refrigerate mixed medicine.

Do not reuse a needle or syringe. Place them in a puncture-proof "sharps" container and dispose of it following state or local laws. Keep out of the reach of children and pets.

Antibiotic medicines can cause diarrhea. Tell your doctor if you have diarrhea that is watery or bloody.

Keep using this medicine even if your symptoms quickly improve. Skipping doses could make your infection resistant to medication. Sulfamethoxazole and trimethoprim will not treat a viral infection (flu or a common cold).

You may need blood and urine tests, and this medicine may be stopped based on the results.

Shake the (liquid). Measure a dose with the supplied measuring device (not a kitchen spoon). oral suspension

Drink plenty of fluids to prevent kidney stones.

Store at room temperature away from moisture, heat, and light. Do not refrigerate.

What should I do if I missed a dose of Bactrim (Sulfamethoxazole and Trimethoprim Oral/Injection)?

Use the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. use two doses at one time. Do not

Overdose Signs

What happens if I overdose on Bactrim (Sulfamethoxazole and Trimethoprim Oral/Injection)?

Overdose symptoms may include loss of appetite, vomiting, fever, blood in your urine, yellowing of your skin or eyes, confusion, or loss of consciousness.

If you think you or someone else may have overdosed on: Bactrim (Sulfamethoxazole and Trimethoprim Oral/Injection), call your doctor or the Poison Control center

(800) 222-1222

If someone collapses or isn't breathing after taking Bactrim (Sulfamethoxazole and Trimethoprim Oral/Injection), call 911

911