Brand Names:

• Bactrim
• Bactrim DS
• Septra
• Septra DS
• Sulfatrim
• Sulfatrim Pediatric
• Apo-Sulfatrim
• Novo-Trimel
• Nu-Cotrimox
• Septa Pediatric
• Septra Pediatric Suspension

Dosage Forms:

• Tablet
• Suspension
• Capsule
• Liquid

Uses of This Medicine:

Sulfonamide and trimethoprim combinations are used to prevent and treat infections. Sulfadiazine and trimethoprim combination is used to treat urinary tract infections. Sulfamethoxazole and trimethoprim combination is used to treat infections, such as bronchitis, middle ear infection, urinary tract infection, and traveler's diarrhea. It is also used for the prevention and treatment of Pneumocystis carinii pneumonia (PCP). These medicines will not work for colds, flu, or other virus infections. They may also be used for other conditions as determined by your doctor.

Sulfonamide and trimethoprim combinations are available only with your doctor's prescription.

Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although these uses are not included in product labeling, sulfamethoxazole and trimethoprim combination is used in certain patients for the following medical conditions:

• Bile infections
• Bone and joint infections
• HIV-related infections in Africa
• Sexually transmitted diseases, such as gonorrhea
• Sinus infections
• Toxoplasmosis (prevention of)
• Urinary tract infections (prevention of)
• Whipple's disease

Before Using This Medicine:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to medicines in this group or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Children

Sulfadiazine and trimethoprim combination should not be given to infants less than 3 months of age. Sulfamethoxazole and trimethoprim combination should not be given to infants less than 2 months of age unless directed by the child's doctor. These combinations may cause unwanted effects. In special situations, sulfamethoxazole and trimethoprim combination may be given to infants less than 2 months of age.

Older adults

Elderly people are especially sensitive to the effects of sulfonamide and trimethoprim combinations. Severe skin problems and blood problems may be more likely to occur in the elderly. These problems may also be more likely to occur in patients who are taking diuretics (water pills) along with this medicine.

Pregnancy

Sulfamethoxazole and trimethoprim combination has not been reported to cause birth defects or other problems in humans. However, studies in mice, rats, and rabbits have shown that some sulfonamides cause birth defects, including cleft palate and bone problems. Studies in rabbits have also shown that trimethoprim causes birth defects, as well as a decrease in the number of successful pregnancies. Sulfonamides are not recommended for use at the time of labor and delivery because these medicines may cause unwanted effects in the baby.

Breast-feeding

Sulfonamides and trimethoprim pass into the breast milk. These medicines are not recommended for use during breast-feeding. They may cause liver problems, anemia, and other unwanted effects in nursing babies, especially those with glucose-6-phosphate dehydrogenase (G6PD) deficiency.

Other medicines

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

• Bepridil
• Cisapride
• Dofetilide
• Levomethadyl
• Mesoridazine
• Pimozide
• Terfenadine
• Thioridazine

Using medicines in this class with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Acecainide
• Acenocoumarol
• Ajmaline
• Amiodarone
• Amisulpride
• Amitriptyline
• Amoxapine
• Aprindine
• Arsenic Trioxide
• Astemizole
• Azimilide
• Bretylium
• Chloral Hydrate
• Chloroquine
• Chlorpromazine
• Clarithromycin
• Desipramine
• Dibenzepin
• Disopyramide
• Dolasetron
• Doxepin
• Droperidol
• Enflurane
• Erythromycin
• Flecainide
• Fluconazole
• Fluoxetine
• Foscarnet
• Gemifloxacin
• Halofantrine
• Haloperidol
• Halothane
• Hydroquinidine
• Ibutilide
• Imipramine
• Isoflurane
• Isradipine
• Lidoflazine
• Lorcainide
• Mefloquine
• Methotrexate
• Nortriptyline
• Octreotide
• Pentamidine
• Pirmenol
• Prajmaline
• Probucol
• Procainamide
• Prochlorperazine
• Propafenone
• Pyrimethamine
• Quetiapine
• Quinidine
• Risperidone
• Sematilide
• Sertindole
• Sotalol
• Spiramycin
• Sultopride
• Tedisamil
• Telithromycin
• Trifluoperazine
• Trimipramine
• Vasopressin
• Warfarin
• Zolmitriptan
• Zotepine

Other interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using medicines in this class with any of the following is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use your medicine, or give you special instructions about the use of food, alcohol, or tobacco.

• Ethanol

Other medical problems

The presence of other medical problems may affect the use of medicines in this class. Make sure you tell your doctor if you have any other medical problems, especially:

• Anemia or other blood problems or
• Glucose-6-phosphate dehydrogenase (G6PD) deficiency Patients with these problems may have an increase in side effects affecting the blood.

• Kidney disease or
• Liver disease Patients with kidney and/or liver disease may have an increased chance of side effects.

• Porphyria This medicine may bring on an attack of porphyria.

Proper Use of This Medicine:

Sulfadiazine and trimethoprim combination should not be given to infants less than 3 months of age, and sulfamethoxazole and trimethoprim combination should not be given to infants less than 2 months of age unless directed by the child's doctor. These medicines may cause unwanted effects in the baby. In special situations, sulfamethoxazole and trimethoprim combination may be given to infants less than 2 months of age.

Sulfonamide and trimethoprim combinations are best taken with a full glass (8 ounces) of water. Several additional glasses of water should be taken every day, unless otherwise directed by your doctor. Drinking extra water will help to prevent some unwanted effects of sulfonamides.

For patients taking the oral liquid form of this medicine:

• Use a specially marked measuring spoon or other device to measure each dose accurately. The average household teaspoon may not hold the right amount of liquid.

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

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 day and night. If you need help in planning the best times to take your medicine, check with your health care professional.

Dosing

The dose medicines in this class 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 these medicines. 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 forms (suspension, tablets):
  • For bacterial infections:
    • Adults and teenagers 820 milligrams (mg) of sulfadiazine and 180 mg of trimethoprim once a day.
    • Infants 3 months of age and older and children up to 12 years of age Dose is based on body weight. The usual dose is 7 mg of sulfadiazine and 1.5 mg of trimethoprim per kilogram (kg) (3.2 mg of sulfadiazine and 0.7 mg of trimethoprim per pound) of body weight every twelve hours.
    • Infants less than 3 months of age Use is not recommended.

• For oral dosage forms (suspension, tablets):
  • For bacterial infections:
    • Adults and children 40 kilograms (kg) of body weight (88 pounds) and over 800 milligrams (mg) of sulfamethoxazole and 160 mg of trimethoprim every twelve hours.
    • Infants 2 months of age and older and children up to 40 kg of weight (88 pounds) Dose is based on body weight. The usual dose is 20 to 30 mg of sulfamethoxazole and 4 to 6 mg of trimethoprim per kg (9.1 to 13.6 mg of sulfamethoxazole and 1.8 to 2.7 mg of trimethoprim per pound) of body weight every twelve hours.
    • Infants less than 2 months of age Use is not recommended.
  • For the treatment of Pneumocystis carinii pneumonia (PCP):
    • Adults and children older than 2 months Dose is based on body weight. The usual dose is 18.75 to 25 mg of sulfamethoxazole and 3.75 to 5 mg of trimethoprim per kg (8.5 to 11.4 mg of sulfamethoxazole and 1.7 to 2.3 mg of trimethoprim per pound) of body weight every six hours.
  • For the prevention of Pneumocystis carinii pneumonia (PCP):
    • Adults and teenagers 800 mg of sulfamethoxazole and 160 mg of trimethoprim once a day.
    • Infants and children 4 weeks of age and older Dose is based on body size and must be determined by your doctor. There are several dosing regimens available that your doctor may choose from. One dosing regimen is 375 mg of sulfamethoxazole and 75 mg of trimethoprim per square meter of body surface two times a day, three times a week on consecutive days (e.g., Monday, Tuesday, Wednesday).
• For injection dosage form:
  • For bacterial infections:
    • Adults and children older than 2 months The usual total daily dose is 40 to 50 mg of sulfamethoxazole and 8 to 10 mg of trimethoprim per kg (18.2 to 22.7 mg of sulfamethoxazole and 3.6 to 4.5 mg of trimethoprim per pound) of body weight. This total daily dose may be divided up and injected into a vein every six, eight, or twelve hours.
    • Infants less than 2 months of age Use is not recommended.
  • For the treatment of Pneumocystis carinii pneumonia (PCP):
    • Adults and children older than 2 months The usual dose is 18.75 to 25 mg of sulfamethoxazole and 3.75 to 5 mg of trimethoprim per kg (8.5 to 11.4 mg of sulfamethoxazole and 1.7 to 2.3 mg of trimethoprim per pound) of body weight. This is injected into a vein every six hours.
    • Infants less 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

Keep out of the reach of children.

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

Do not keep outdated medicine or medicine no longer needed.

Precautions While Using This Medicine:

It is very important that your doctor check your progress at regular visits. This medicine may cause blood problems, especially if it is taken for a long time.

If your symptoms do not improve within a few days, or if they become worse, check with your doctor.

Sulfonamide and trimethoprim combinations may cause blood problems. These problems may result in a greater chance of certain infections, slow healing, and bleeding of the gums. Therefore, you should be careful when using regular toothbrushes, dental floss, and toothpicks. Dental work should be delayed until your blood counts have returned to normal. Check with your medical doctor or dentist if you have any questions about proper oral hygiene (mouth care) during treatment.

Sulfonamide and trimethoprim combinations may cause your skin to be more sensitive to sunlight than it is normally. Exposure to sunlight, even for brief periods of time, may cause a skin rash, itching, redness or other discoloration of the skin, or a severe sunburn. When you begin taking this medicine:

• Stay out of direct sunlight, especially between the hours of 10:00 a.m. and 3:00 p.m., if possible.
• Wear protective clothing, including a hat and sunglasses.
• Apply a sun block product that has a skin protection factor (SPF) of at least 15. Some patients may require a product with a higher SPF number, especially if they have a fair complexion. If you have any questions about this, check with your health care professional.
• Apply a sun block lipstick that has an SPF of at least 15 to protect your lips.
• Do not use a sunlamp or tanning bed or booth.

If you have a severe reaction from the sun, check with your doctor.

This medicine may also cause some people to become dizzy. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert. If this reaction is especially bothersome, check with your doctor.

Side Effects of This Medicine:

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

Itching

skin rash

Less common

Aching of joints and muscles

difficulty in swallowing

pale skin

redness, blistering, peeling, or loosening of skin

sore throat and fever

unusual bleeding or bruising

unusual tiredness or weakness

yellow eyes or skin

Rare

Abdominal or stomach cramps and pain (severe)

abdominal or stomach tenderness

anxiety

blood in urine

bluish fingernails, lips, or skin

confusion

diarrhea (watery and severe), which may also be bloody

difficult breathing

drowsiness

fever

general feeling of illness

greatly increased or decreased frequency of urination or amount of urine

hallucinations

headache, severe

increased thirst

lower back pain

mental depression

muscle pain or weakness

nausea

nervousness

pain at site of injection

pain or burning while urinating

seizures (convulsions)

stiff neck and/or back

swelling of front part of neck

Some of the above side effects (severe abdominal or stomach cramps and pain, and watery and severe diarrhea, which may also be bloody) may also occur up to several weeks after you stop using any of these medicines.

Check with your doctor as soon as possible if any of the following side effects occur:

More common

Increased sensitivity of skin to sunlight

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 tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Diarrhea

dizziness

headache

loss of appetite

mouth sores or swelling of the tongue

nausea or vomiting

tiredness

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