Some commonly used brand names are:

In the U.S.—

In Canada—

Another commonly used name for sulfisoxazole is sulfafurazole.

• Antibacterial, ophthalmic --Sulfacetamide; Sulfisoxazole

Sulfonamides (sul-FON-a-mides ) , or sulfa medicines, belong to the family of medicines called anti-infectives. Sulfonamide ophthalmic preparations are used to treat infections of the eye.

Sulfonamides are available only with your doctor's prescription, in the following dosage forms:

Ophthalmic
• Sulfacetamide
  • Ophthalmic ointment (U.S. and Canada)
  • Ophthalmic solution (eye drops) (U.S. and Canada)
• Sulfisoxazole
  • Ophthalmic ointment (U.S.)
  • Ophthalmic solution (eye drops) (U.S.)

In deciding to use a medicine, the risks of using the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For sulfonamide ophthalmic preparations, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to any of the sulfa medicines; furosemide (e.g., Lasix) or thiazide diuretics (water pills); oral antidiabetics (diabetes medicine you take by mouth); or glaucoma medicine you take by mouth (for example, acetazolamide [e.g., Diamox], dichlorphenamide [e.g., Daranide], or methazolamide [e.g., Neptazane]). Also tell your health care professional if you are allergic to any other substances, such as preservatives.

Pregnancy—Sulfonamide ophthalmic preparations have not been shown to cause birth defects or other problems in humans.

Breast-feeding—Sulfonamide ophthalmic preparations have not been reported to cause problems in nursing babies.

Children—Studies on sulfonamide ophthalmic preparations have been done only in adult patients, and there is no specific information comparing use in children with use in other age groups.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of sulfonamides in the elderly with use in other age groups.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking sulfonamide ophthalmic preparations, it is especially important that your health care professional know if you are using any of the following:

• Silver preparations, such as silver nitrate or mild silver protein for the eye—Sulfonamide ophthalmic preparations should not be used with silver ophthalmic preparations, since a chemical reaction may occur.

For patients using the eye drop form of sulfonamides:

• The bottle is only partially full to provide proper drop control.
• To use:
  • First, wash your hands. Then tilt the head back and pull the lower eyelid away from the eye to form a pouch. Drop the medicine into the pouch and gently close the eyes. Do not blink. Keep the eyes closed for 1 or 2 minutes to allow the medicine to come into contact with the infection.
  • If you think you did not get the drop of medicine into your eye properly, use another drop.
  • To keep the medicine as germ-free as possible, do not touch the applicator tip to any surface (including the eye). Also, keep the container tightly closed.

For patients using the eye ointment form of sulfonamides:

• To use:
  • First, wash your hands. Then pull the lower eyelid away from the eye to form a pouch. Squeeze a thin strip of ointment into the pouch. A 1.25- to 2.5-cm (approximately ½- to 1-inch) strip of ointment is usually enough unless otherwise directed by your doctor. Gently close the eyes and keep them closed for 1 or 2 minutes to allow the medicine to come into contact with the infection.
  • To keep the medicine as germ-free as possible, do not touch the applicator tip to any surface (including the eye). After using sulfonamides eye ointment, wipe the tip of the ointment tube with a clean tissue and keep the tube tightly closed.

To help clear up your infection completely, keep using this medicine for the full time of treatment, even if your symptoms have disappeared. Do not miss any doses.

Dosing—

The dose of ophthalmic sulfonamides 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 ophthalmic sulfonamides. If your dose is different, do not change it unless your doctor tells you to do so.

The number of doses you use each day, the time allowed between doses, and the length of time you use the medicine depend on the medical problem for which you are using ophthalmic sulfonamides.

For sulfacetamide
• For eye infections:
  • For ophthalmic dosage forms (ointment):
    • Adults and adolescents—Use four times a day and at bedtime.
    • Children—Use and dose must be determined by your doctor.
  • For ophthalmic dosage forms (solution):
    • Adults and adolescents—One drop every one to three hours during the day and less often during the night.
    • Children—Use and dose must be determined by your doctor.

For sulfisoxazole
• For eye infections:
  • For ophthalmic dosage forms (ointment):
    • Adults and children—Use one to three times a day and at bedtime.
  • For ophthalmic dosage forms (solution):
    • Adults and adolescents—One drop three or more times a day.
    • Children—
      • Infants up to 2 months of age: Use and dose must be determined by your doctor.
      • Infants and children 2 months of age and older: One drop three or more times a day.

Missed dose—

If you miss a dose of this medicine, apply 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.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Keep sulfacetamide eye drops in a cool place. Keep all dosage forms of these medicines from freezing.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

After application, eye ointments usually cause your vision to blur for a few minutes.

After application of this medicine to the eye, occasional stinging or burning may be expected.

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

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 as soon as possible if any of the following side effects occur:

• More common
  • Itching, redness, swelling, or other sign of irritation not present before use of this medicine 
  
  

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