Sulfamethoxazole-trimethoprim
InfectionsAlso known as Bactrim
This is two antibiotics in one pill, and the combo hits bacteria harder than either alone. It's a common pick for urinary tract infections, certain skin infections including MRSA, and some lung infections. It's a sulfa drug — so if you've ever had a sulfa allergy, do not take it and make sure your doctor knows. It's useless against viruses, so it won't help a cold.
How to take it
When
Space doses evenly and take each one with a full glass of water, exactly as prescribed.
Food
Works with or without food. Drink plenty of water throughout the day — it protects your kidneys.
Avoid
Never take it with a sulfa allergy. Tell your doctor if you take warfarin — this drug can make it dangerously stronger.
Good to know
It can raise potassium levels. Your doctor may check blood work if you take certain blood pressure medicines.
Missed a dose?
Take it as soon as you remember. If it's nearly time for your next dose, skip the missed one and get back on schedule. Never take two doses at once.
Common side effects
- Nausea or loss of appetite
- Mild rash or itching — but tell your doctor about any rash
- Sunburn more easily
- Headache
Call a doctor if
- Any spreading rash, blistering, peeling skin, or sores in your mouth — stop the drug and get help now. Sulfa drugs can cause rare but life-threatening skin reactions.
- Trouble breathing, swelling of the face or throat, or hives — serious allergic reaction. Get emergency help now.
- Fever, sore throat, unusual bruising, or paleness — this drug can rarely affect blood cells. Call your doctor right away.
- Severe watery or bloody diarrhea, during treatment or even weeks after — possible C. diff gut infection. Call your doctor; don't just take anti-diarrhea medicine.
- Unusual bleeding if you take warfarin — call your doctor now.