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Sulfisoxazole (Oral)

Generic name: sulfisoxazole

Brand names: Gantrisin Pediatric, Truxazole

Last updated August 19, 2026 0 views
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Uses for sulfisoxazole

Sulfisoxazole is used to treat or prevent infections in various parts of the body. It is part of a group of medicines called sulfonamide antibiotics. It works by stopping the growth of bacteria. However, this medicine will not work for colds, flu, or other viral infections.

This medicine is available only with your doctor's prescription.

This section was rewritten for readability and reviewed for meaning.

Precautions while using sulfisoxazole

If your symptoms do not improve within a few days or if they get worse, contact your doctor.

Serious skin reactions can happen with this medicine. Stop using this medicine and contact your doctor immediately if you notice any of the following symptoms: a skin rash; blistering, peeling, or loosening of the skin; cough; diarrhea; itching; sores, ulcers, or white spots in the mouth or on the lips; or unusual tiredness or weakness.

Contact your doctor right away if you have fever; chills; joint or muscle pain; pale skin; pinpoint red or purple spots on the skin; shortness of breath; sore throat; pain in the upper stomach; or yellowing of the eyes or skin. These could be signs of a serious blood problem.

Sulfisoxazole may cause diarrhea, and in some cases, it can be severe. Do not take any medicine to treat diarrhea without first checking with your doctor. Diarrhea medicines may worsen the diarrhea or prolong it. If mild diarrhea continues or worsens, contact your doctor.

Do not take other medicines unless you have discussed them with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

This section was rewritten for readability and reviewed for meaning.

Before using sulfisoxazole

In deciding to use a medicine, you and your doctor must consider the risks of taking the medicine against the benefits it may provide. For this medicine, consider the following:

Allergies

Inform your doctor if you have ever had any unusual or allergic reactions to this medicine or any other medicines. Also, let your healthcare professional know if you have any other allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Due to the toxicity of sulfisoxazole, it is not recommended for infants younger than 2 months of age.

Geriatric

There is no information available on how age affects the use of sulfisoxazole in older patients. However, elderly patients are more likely to have kidney and liver issues related to age, which may require caution when taking sulfadiazine.

Breast Feeding

Studies suggest that this medication poses minimal risk to infants when used during breastfeeding.

Interactions with Medicines

Some medicines should not be used together, while others may be used together even if an interaction could happen. In these cases, your doctor may need to adjust the dose or take other precautions. When taking this medicine, it is very important that your healthcare professional knows if you are taking any of the following medicines. The interactions listed below are important but not all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may choose not to treat you with this medication or may change some of the other medicines you take.

  • Methenamine

Using this medicine with any of the following medicines is usually not recommended, but may be necessary in some cases. If both medicines are prescribed together, your doctor may adjust the dose or the frequency of one or both medicines.

  • Methotrexate
  • Porfimer
  • Warfarin

Using this medicine with any of the following medicines may increase the risk of certain side effects, but taking both medicines may be the best treatment for you. If both are prescribed together, your doctor may adjust the dose or frequency of one or both medicines.

  • Acetohexamide
  • Aminolevulinic Acid

Interactions with Food/Tobacco/Alcohol

Some medicines should not be taken around the time of eating food or certain types of food due to possible interactions. Using alcohol or tobacco with certain medicines may also lead to interactions. Discuss with your healthcare professional about using your medicine with food, alcohol, or tobacco.

Other Medical Problems

Having other medical conditions may affect the use of this medicine. Be sure to tell your doctor if you have any other medical issues, especially:

  • Asthma or
  • Blood problems (e.g., agranulocytosis, aplastic anemia) or
  • Glucose-6-phosphate dehydrogenase (G6PD) deficiency (an enzyme issue) or
  • Kidney disease or
  • Liver disease—Use with caution. This may increase the chance of side effects.

This section was rewritten for readability and reviewed for meaning.

Side Effects of sulfisoxazole

Along with its necessary effects, a medicine can also cause some unwanted effects. Not all of these side effects may happen, but if they do, they might need medical attention.

Check with your doctor right away if any of these side effects occur:

Rare

  • Anxiety
  • blurred vision
  • changes in menstrual periods
  • chills
  • cold sweats
  • coma
  • confusion
  • cool, pale skin
  • decreased sexual ability in males
  • depression
  • dizziness
  • dry, puffy skin
  • fast heartbeat
  • feeling cold
  • headache
  • increased hunger
  • nausea
  • nervousness
  • nightmares
  • seizures
  • shakiness
  • slurred speech
  • swelling of the front part of the neck
  • unusual tiredness or weakness
  • weight gain

Incidence not known

  • Abdominal or stomach pain, cramps, or tenderness
  • agitation
  • back, leg, or stomach pains
  • bleeding gums
  • bleeding under the skin
  • blindness or vision changes
  • blistering, peeling, or loosening of the skin
  • bloating
  • bloody or cloudy urine
  • bloody, black, or tarry stools
  • bluish color of the fingernails, lips, skin, palms, or nail beds
  • burning of the face or mouth
  • burning, crawling, itching, numbness, painful, prickling, "pins and needles", or tingling feelings
  • change in the ability to see colors, especially blue or yellow
  • chest pain
  • chills
  • clay-colored stools
  • clumsiness or unsteadiness
  • constipation
  • continuing ringing or buzzing or other unexplained noise in the ears
  • cough or hoarseness
  • cracks in the skin
  • dark urine
  • decrease in frequency of urination
  • decrease in the amount of urine
  • diarrhea
  • diarrhea, watery and severe, which may also be bloody
  • difficult or painful urination
  • difficulty in passing urine (dribbling)
  • difficulty with breathing
  • difficulty with swallowing
  • dizziness or lightheadedness
  • drowsiness
  • enlarged salivary glands
  • fainting
  • fast, pounding, or irregular heartbeat or pulse
  • feeling of discomfort
  • feeling unusually cold
  • fever with or without chills
  • general body swelling
  • general feeling of discomfort or illness
  • general feeling of tiredness or weakness
  • hair loss
  • headache
  • hearing loss
  • hives or welts
  • hostility
  • increased sensitivity of the skin to sunlight
  • increased thirst
  • indigestion
  • inflammation of the joints
  • irritability
  • itching
  • joint or muscle pain
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • lethargy
  • light-colored stools
  • loss of appetite and weight
  • loss of heat from the body
  • loss of strength or energy
  • lower back or side pain
  • muscle aches
  • muscle pain or weakness
  • muscle twitching
  • nosebleeds
  • not able to pass urine
  • pain
  • pain or burning while urinating
  • pains in the stomach, side, or abdomen, possibly radiating to the back
  • pale skin
  • pinpoint red or purple spots on the skin
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • rapid heart rate
  • rapid weight gain
  • rash
  • red skin lesions, often with a purple center
  • red, irritated eyes
  • red, swollen skin
  • redness of the white part of the eyes
  • redness, soreness or itching skin
  • scaly skin
  • severe sunburn
  • shakiness and unsteady walk
  • shivering
  • shortness of breath
  • skin rash
  • sore throat
  • soreness of the muscles
  • sores, ulcers, or white spots on the lips or in the mouth
  • sores, welting, or blisters
  • stupor
  • swelling around the eyes
  • swelling of face, ankles, hands, feet, or lower legs
  • swelling or inflammation of the mouth
  • swollen lymph glands
  • swollen or painful glands
  • thickening of bronchial secretions
  • tightness in the chest
  • troubled breathing
  • troubled breathing with exertion
  • unpleasant breath odor
  • unsteadiness, trembling, or other problems with muscle control or coordination
  • unusual bleeding or bruising
  • unusual weak feeling
  • unusual weight gain
  • unusual weight loss
  • upper right abdominal pain
  • vomiting
  • vomiting of blood or material that looks like coffee grounds
  • weakness in the hands or feet
  • weight loss
  • wheezing
  • yellow eyes or skin

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to provide ways to prevent or reduce some of these side effects. Check with your health care professional if any of these side effects continue or are bothersome, or if you have any questions about them:

Incidence not known

  • Confusion about identity, place, and time
  • difficulty with moving
  • excess air or gas in the stomach or intestines
  • fear
  • feeling of constant movement of self or surroundings
  • feeling that others are watching you or controlling your behavior
  • feeling that others can hear your thoughts
  • feeling, seeing, or hearing things that are not there
  • full feeling
  • lack of feeling or emotion
  • passing gas
  • redness, swelling, or soreness of the tongue
  • sensation of spinning
  • severe mood or mental changes
  • sleeplessness
  • trouble with sleeping
  • unable to sleep
  • uncaring
  • unusual behavior

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

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

In the U.S.

  • Gantrisin Pediatric
  • Truxazole

Chemical Class: Sulfonamide

This section was rewritten for readability and reviewed for meaning.

Proper use of sulfisoxazole

This medicine should not be given to infants younger than 2 months of age unless directed by your child's doctor. Sulfisoxazole may cause serious unwanted effects in this age group.

Take this medicine with a full glass (8 ounces) of water. Several additional glasses of water should be taken during the day, unless otherwise directed by your doctor. Drinking extra water will help to prevent some unwanted effects.

This medicine works best when there is a constant amount in the blood or urine. To help keep the amount constant, do not miss any doses. Also, it is best to take the doses at evenly spaced times during the day. If you need help in planning the best times to take your medicine, check with your doctor.

To help clear up your infection completely, keep using this medicine for the full treatment time, even if you feel better after the first few doses. If you stop taking this medicine too soon, your symptoms may return.

Shake the oral suspension well before each use. Measure the medicine with a marked measuring spoon, oral syringe, or medicine cup. The average household teaspoon may not hold the right amount of liquid.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (suspension, tablets):For treatment of infections: Adults—4000 to 8000 milligrams (mg) per day, divided and given in 4 to 6 doses per day. Children and infants 2 months of age and older—Dose is based on body weight and must be determined by your doctor. The starting dose is usually 75 milligrams (mg) per kilogram (kg) of body weight per day (mg/kg/day), divided and given in 4 to 6 doses per day. Your doctor may increase your dose to 150 mg/kg/day, but the total dose is usually not more than 6000 mg per day. Infants younger than 2 months of age—Use is not recommended.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Related medicines

Before you take this medicine: the information on this page is general and may not cover your personal circumstances. Read the label supplied with your medicine and ask a pharmacist or doctor if you are unsure, especially if you are pregnant, breastfeeding, taking other medicines or managing a long-term condition.
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Content is provided for education and is not medical advice. See our medical disclaimer.