SALICYLIC ACID OINTMENT

Indications

• Acne vulgaris
• Psoriasis
• Warts
• Seborrheic dermatitis
• Dandruff
• Hyperkeratotic conditions

Dosage

Children: Refer to appropriate paediatric guidelines as per product formulation.

Adults: Topical application varies by formulation; follow specific product guidelines.

Mechanism of action

Salicylic acid exerts its effects by penetrating the skin and dissolving the bonds that hold skin cells together, which facilitates the removal of the outer layer of skin. It also has anti-inflammatory properties that help reduce the redness and swelling associated with acne and other skin disorders. Salicylic acid is known to inhibit the enzyme cyclooxygenase (COX), leading to decreased production of inflammatory mediators.

Pharmacodynamics

Salicylic acid demonstrates keratolytic effects by softening and loosening the outer layer of skin. Its ability to penetrate hair follicles allows it to address acne at its source by clearing plugged pores. The anti-inflammatory action reduces the inflammatory response in acne lesions, leading to a decrease in swelling and redness. The concentration of salicylic acid used affects its effectiveness; higher concentrations are typically utilized for more severe conditions.

Pharmacokinetics

Salicylic acid is absorbed through the skin, with systemic absorption being minimal when used topically. The onset of action can vary depending on the formulation and concentration used. The metabolic pathways primarily involve conjugation with glycine or glucuronic acid in the liver, leading to excretion via the kidneys. Its half-life can vary, but topical formulations are designed for localized effects, minimizing systemic exposure.

Contra-indications

• Hypersensitivity to salicylic acid or any of its components
• Active peptic ulcer disease
• Severe liver or kidney impairment
• Children and adolescents with viral infections (risk of Reye's syndrome)

Adverse effects

• Gastrointestinal disturbance (nausea, vomiting, dyspepsia)
• Tinnitus or hearing loss (especially at high doses)
• Allergic reactions (including rash or urticaria)
• Skin irritation or burning sensation (when used topically)
• Respiratory alkalosis (in cases of overdose)

Interactions

• Increased risk of bleeding when used with anticoagulants such as warfarin
• Potential interaction with methotrexate, leading to increased toxicity
• May decrease the efficacy of certain antihypertensive medications
• Use with caution in conjunction with other non-steroidal anti-inflammatory drugs (NSAIDs)

Precautions

• Caution in patients with asthma or a history of asthma
• Use with caution in patients with a history of gastrointestinal disorders
• Regular monitoring of renal function may be necessary in long-term use
• Avoid in patients with known salicylate intolerance

Pregnancy

Salicylic acid is generally avoided during pregnancy, especially in the third trimester, due to potential risks of fetal harm.

Breast-feeding

Salicylic acid is excreted in breast milk; caution is advised when using topically or systemically.

Storage

Store in a cool, dry place away from light. Keep out of reach of children.

Formulations

• Topical ointment or gel
• Liquid solution for topical use
• Tablets and capsules for systemic use