Product Description.:
Keralyt? Gel (salicylic acid) 6% Rx only
FOR TOPICAL USE ONLY. NOT FOR OPHTHALMIC, ORAL OR INTRAVAGINAL USE.
DESCRIPTION: KERALYT? is a gel for topical administration containing 6% salicylic acid in a vehicle composed of propylene glycol, SD-40 alcohol (21%), hydroxypropylcellulose and purified water. Salicylic acid is the 2 hydroxy derivative of benzoic acid having the following structure:
CLINICAL PHARMACOLOGY: Salicylic acid has been shown to produce desquamation of the horny layer of skin while not effecting qualitative or quantitative changes in structure of the viable epidermis.1,2 The mechanism of action has been attributed to a dissolution of intercellular cement substance.3 In a study of the percutaneous absorption of salicylic acid from KERALYT GEL in four patients with extensive active psoriasis, Taylor and Halprin4 showed that peak serum salicylate levels never exceeded 5 mg/100 ml even though more than 60% of the applied salicylic acid was absorbed. Systemic toxic reactions are usually associated with much higher serum levels (30 to 40 mg/100 ml). Peak serum levels occurred within 5 hours of the topical application under occlusion. The sites were occluded for 10 hours over the entire body surface below the neck. Since salicylates are distributed in the extracellular space, patients with a contracted extracellular space due to dehydration or diuretics have higher salicylate levels than those with a normal extracellular space.5 (See PRECAUTIONS).
The major metabolites identified in the urine after topical administration are salicyluric acid (52%), salicylate glucuronides (42%), and free salicylic acid (6%).4 The urinary metabolites after percutaneous absorption differ from those after oral salicylate administration those derived from percutaneous absorption contain more glucuronides and less salicyluric and salicylic acid. Almost 95% of a single dose of salicylate is excreted within 24 hours of its entrance into the extracellular space.5
Fifty to eighty percent of salicylate is protein bound to albumin. Salicylates compete with the binding of several drugs and can modify the action of these drugs. By similar competitive mechanisms other drugs can influence the serum levels of salicylate.5 (See PRECAUTIONS).
INDICATIONS AND USAGE - For the removal of excess keratin in hyperkeratotic disorders, including scaling associated with psoriasis or thickened skin of palms and soles, corns and calluses.
CONTRAINDICATIONS: KERALYT GEL should not be used in any patient known to be sensitive to salicylic acid or any other listed ingredient. KERALYT should not be used in children under 2 years of age.
WARNINGS: Prolonged use over large areas, especially in children and those patients with significant renal or hepatic impairment, could result in salicylism. Concomitant use of other drugs which may contribute to elevated serum salicylate levels should be avoided where the potential for toxicity is present. In children under 12 years of age and those patients with renal or hepatic impairment, the area to be treated should be limited and the patient monitored closely for signs of salicylate toxicity: nausea, vomiting, dizziness, loss of hearing, tinnitus, lethargy, hyperpnoea, diarrhea, psychic disturbances. In the event of salicylic acid toxicity, the use of KERALYT GEL should be discontinued. Fluids should be administered to promote urinary excretion. Treatment with sodium bicarbonate (oral or intravenous) should be instituted as appropriate.
Considering the potential risk of developing Reye?s Syndrome, salicylate products should not be administered to children or teenagers with varicella or influenza, unless directed by a physician.
PRECAUTIONS: For external use only. Avoid contact with eyes and other mucous membranes. Mild burning or stinging may occur. Peeling of the skin may increase as the salicylic acid works to loosen excess keratin. If excessive burning, stinging or peeling occurs, discontinue use and consult your physician. Flammable. Keep away from heat and open flame. Keep this and all medications out of reach of children.
Drug Interactions. (The following interactions are from a published review5 and include reports concerning both oral and topical salicylate administration. The relationship of these interactions to the use of KERALYT GEL is not known.)
