Sulfisoxazole and phenazopyridine (patient information)

# IMPORTANT WARNING:
Sulfisoxazole and phenazopyridine is no longer available in the U.S. If you are currently taking sulfisoxazole and phenazopyridine, you should call your doctor to discuss switching to another treatment.

# Why is this medication prescribed
Sulfisoxazole, a sulfa drug, eliminates bacteria that cause urinary tract infections. Phenazopyridine relieves the pain, burning, and the frequent urge to urinate caused by these infections. Antibiotics will not work for colds, flu, or other viral infections.
This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

# How should this medicine be used
The combination of sulfisoxazole and phenazopyridine comes as a tablet to take by mouth. It usually is taken four times a day. Take each dose with a full glass of water. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take sulfisoxazole and phenazopyridine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

# What special precautions should I follow
Before taking sulfisoxazole and phenazopyridine:
- tell your doctor and pharmacist if you are allergic to sulfisoxazole, phenazopyridine, any other sulfa drug, diuretics ('water pills'), oral diabetes medications, or any other drugs.
- tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially anticoagulants ('blood thinners') such as warfarin (Coumadin), cyclosporine (Neoral, Sandimmune), diabetes medications, methotrexate, phenytoin (Dilantin), and vitamins.
- tell your doctor if you have or have ever had liver or kidney disease, asthma, severe allergies, or glucose-6-phosphate dehydrogenase (G-6-PD) deficiency (an inherited blood disease).
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking sulfisoxazole and phenazopyridine, call your doctor.
- plan to avoid unnecessary or prolonged exposure to sunlight and to wear protective clothing, sunglasses, and sunscreen. *Sulfisoxazole and phenazopyridine may make your skin sensitive to sunlight.

# What special dietary instructions should I follow
Sulfisoxazole and phenazopyridine may cause an upset stomach. Take sulfisoxazole and phenazopyridine with food or milk.

# What should I do if I forget a dose
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

# Side effects

## Mild side effects
Sulfisoxazole and phenazopyridine may cause side effects. Your urine may turn red-orange or brown; this effect is harmless. Tell your doctor if any of these symptoms are severe or do not go away:
- diarrhea
- dizziness or loss of balance
- loss of appetite
- upset stomach

## Severe side effects
If you experience any of the following symptoms, call your doctor immediately:
- skin rash or skin changes
- sore throat
- fever
- headache
- joint or muscle aches
- yellowing of the skin or eyes
- swelling of the lips or tongue
- swallowing problems
- tiredness
- unusual bleeding or bruising
- weakness
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online  or by phone .

# What storage conditions are needed for this medicine
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

# In case of emergency/overdose
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

# What other information should I know
Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to sulfisoxazole and phenazopyridine.
Phenazopyridine interferes with laboratory tests, including urine tests for glucose (sugar) and ketones. If you have diabetes, you should use Clinitest rather than Tes-Tape or Clinistix to test your urine for sugar. Urine tests for ketones (Acetest and Ketostix) may give false results. Before you have any tests, tell the laboratory personnel and doctor that you take this medication.
Phenazopyridine stains clothing and contact lenses. Avoid wearing contact lenses while taking this medicine.
Do not let anyone else take your medication. Your prescription probably is not refillable. If you still have symptoms of infection after you finish the sulfisoxazole and phenazopyridine, call your doctor.

# Brand names
- Azo-Sulfisoxazole