Sodium Sulfacetamide

Each mL of Sodium Sulfacetamide Lotion, 10% contains 100 mg of Sodium Sulfacetamide in a vehicle consisting of edetic acid, hydroxyethyl cellulose, lauramide DEA, methylparaben, PEG-400 monolaurate, propylene glycol, purified water, silicone emulsion, sodium chloride, sodium metabisulfite, and xanthan gum.

Sodium Sulfacetamide is a sulfonamide with antibacterial activity. Chemically, Sodium Sulfacetamide is N' -[(4-amino phenyl) sulfonyl] - acetamide, monosodium salt, monohydrate. The structural formula is:

The most widely accepted mechanism of action of sulfonamides is the Woods-Fildes theory, based on sulfonamides acting as a competitive inhibitor of para-aminobenzoic acid (PABA) utilization, an essential component for bacterial growth. While absorption through intact skin in humans has not been determined, in vitro studies with human cadaver skin indicated a percutaneous absorption of about 4%. Sodium Sulfacetamide is readily absorbed from the gastrointestinal tract when taken orally and excreted in the urine largely unchanged. The biological half-life has been reported to be between 7 to 13 hours.

The pharmacokinetics of sulfacetamide and its major metabolite sulfaniliamide in Sodium Sulfacetamide Lotion was evaluated in adult subjects (N=14) with acne vulgaris. The subjects applied Sodium Sulfacetamide Lotion to their face, back, chest, and shoulders every 12 hours for 28 days. The percentage of the applied dose of Sodium Sulfacetamide Lotion excreted in the urine as sulfacetamide plus sulfanilamide ranged from 0.08 to 0.33%.

Sodium Sulfacetamide Lotion is contraindicated for use by patients having known hypersensitivity to sulfonamides or any other component of this preparation (see WARNINGS).

Fatalities have occurred, although rarely, due to severe reactions to sulfonamides including Stevens-Johnson syndrome, toxic epidermal necrolysis, fulminant hepatic necrosis, agranulocytosis, aplastic anemia, and other blood dyscrasias. Hypersensitivity reactions may occur when a sulfonamide is readministered, irrespective of the route of administration. Sensitivity reactions have been reported in individuals with no prior history of sulfonamide hypersensitivity. At the first sign of hypersensitivity, skin rash, or other reactions, discontinue use of this preparation (see ADVERSE REACTIONS).

Sodium Sulfacetamide Lotion contains sodium metabisulfite, a sulfite that may cause allergic-type reactions including anaphylactic symptoms and life-threatening or less severe asthmatic episodes in certain susceptible people. The overall prevalence of sulfite sensitivity in the general population is unknown and probably low. Sulfite sensitivity is seen more frequently in asthmatic than in non-asthmatic people (see CONTRAINDICATIONS).

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Skin irritation.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-FDA-1088. You may also report side effects at http://www.fda.gov/medwatch.

Some side effects of sulfacetamide sodium topical may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.