SULFAMETHOXAZOLE; TRIMETHOPRIM (suhl fuh meth OK suh zohl; trye METH oh prim) treats infections caused by bacteria. It belongs to a group of medications called sulfonamide antibiotics. It will not treat colds, the flu, or infections caused by viruses.
What should I tell my care team before I take this medication?
They need to know if you have any of these conditions:
HIV or AIDS
Low red blood cell counts
Stomach or intestine problems like colitis
An unusual or allergic reaction to sulfamethoxazole, trimethoprim, sulfa medications, other medications, foods, dyes, or preservatives
Pregnant or trying to get pregnant
How should I use this medication?
Take this medication by mouth with a glass of water. Follow the directions on the prescription label. Take your medication at regular intervals. Do not take it more often than directed. Take all of your medication as directed even if you think you are better. Do not skip doses or stop your medication early.
Talk to your care team about the use of this medication in children. While this medication may be prescribed for children as young as 2 months for selected conditions, precautions do apply.
What if I miss a dose?
If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.
What may interact with this medication?
Do not take this medication with any of the following:
This medication may also interact with the following:
Birth control pills
Certain medications for blood pressure, heart disease
Certain medications for depression, like amitriptyline
Certain medications for diabetes, like glipizide or glyburide
Certain medications that treat or prevent blood clots like warfarin
What side effects may I notice from receiving this medication?
Side effects that you should report to your care team as soon as possible:
Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
Aplastic anemia—unusual weakness or fatigue, dizziness, headache, trouble breathing, increased bleeding or bruising, fever, chills, cough, or sore throat
Dry cough, shortness of breath or trouble breathing
High potassium level—muscle weakness, fast or irregular heartbeat
Liver injury— right upper belly pain, loss of appetite, nausea, light-colored stool, dark yellow or brown urine, yellowing skin or eyes, unusual weakness or fatigue
Low blood sugar (hypoglycemia)—tremors or shaking, anxiety, sweating, cold or clammy skin, confusion, dizziness, rapid heartbeat
Low sodium level—muscle weakness, fatigue, dizziness, headache, confusion
Rash, fever, and swollen lymph nodes
Redness, blistering, peeling, or loosening of the skin, including inside the mouth
Severe diarrhea, fever
Small, pus-filled bumps on skin
Unusual vaginal discharge, itching, or odor
Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):
Loss of appetite
What should I watch for while using this medication?
Tell your care team if your symptoms do not start to get better or if they get worse.
Do not treat diarrhea with over the counter products. Contact your care team if you have diarrhea that lasts more than 2 days or if it is severe and watery.
This medication may cause serious skin reactions. They can happen weeks to months after starting the medication. Contact your care team right away if you notice fevers or flu-like symptoms with a rash. The rash may be red or purple and then turn into blisters or peeling of the skin. Or, you might notice a red rash with swelling of the face, lips or lymph nodes in your neck or under your arms.
This medication can make you more sensitive to the sun. Keep out of the sun. If you cannot avoid being in the sun, wear protective clothing and sunscreen. Do not use sun lamps or tanning beds/booths.
Be careful brushing or flossing your teeth or using a toothpick because you may get an infection or bleed more easily. If you have any dental work done, tell your dentist you are receiving this medication.
Where should I keep my medication?
Keep out of the reach of children.
Store between 15 and 25 degrees C (59 to 77 degrees F). Protect from light. Keep the container tightly closed. Throw away any unused medication after the expiration date.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.
This information is educational only and should not be construed as specific instructions for individual patients nor as a substitute for medical advice, diagnosis or treatment. Talk to your health care provider or pharmacist about the information and instructions. K Health assumes no liability for any use or reliance on this information.