Sulfamethoxazole (By mouth)

Sulfamethoxazole (sul-fa-meth-OX-a-zole)

Treats urinary tract infections, ear infections, and other general infections caused by bacteria. May also be given in combination with other medicines. Belongs to a class of drugs called sulfonamides (sulfa drugs).

Brand Name(s):

There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

You should not use this medicine if you have had an allergic reaction to sulfamethoxazole or to any other sulfa drug. You should not use this medicine if you will soon be having a baby or if you are breastfeeding.

How to Use This Medicine:

Tablet

Your doctor will tell you how much of this medicine to use and how often. Do not use more medicine or use it more often than your doctor tells you to.
Drink plenty of water while using this medicine.
Use this medicine for the full time of treatment, even if you begin to feel better. If you stop using this medicine too soon, your infection may come back.

If a dose is missed:

Use your medicine as soon as possible unless it is almost time for your next dose.
Skip the missed dose if it is almost time for your next regular dose.
Do not use two doses at the same time.

How to Store and Dispose of This Medicine:

Store at room temperature in a closed container, away from heat, moisture, and direct light.
Keep this and all medicine out of the reach of children.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

Make sure your doctor knows if you are also using Coumadin®, Dilantin®, or methotrexate.

Warnings While Using This Medicine:

If you are pregnant or breastfeeding, talk to your doctor before using this medicine.
Make sure your doctor knows if you have kidney or liver disease, asthma, or G6PD (glucose-6-phosphate dehydrogenase) deficiency.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

Fainting
Fast or irregular heartbeat
Fever
Muscles aches
Rash, blistering, or purple spots on the skin
Shortness of breath
Skin rash, hives, or itching
Sore throat or cough
Swelling in face, throat, or lips
Wheezing or trouble breathing
Yellow eyes or yellow or pale skin

If you notice these less serious side effects, talk with your doctor:

Headache
Nausea, vomiting, or diarrhea

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 1/27/2017