Motusol (Diclofenac Sodium)

• Diclofenac sodium is used topically to manage inflammatory and painful conditions of the musculoskeletal system.
• Musculoskeletal pain: provides localized analgesia and reduces inflammation at the site of pain.
• Arthritis: alleviates joint swelling and stiffness, improving mobility.
• Soft‑tissue inflammation: diminishes swelling and erythema in tendons, bursae or bruised areas.

• Diclofenac sodium exerts its anti‑inflammatory effect by reversibly inhibiting cyclooxygenase‑1 (COX‑1) and cyclooxygenase‑2 (COX‑2) enzymes in peripheral tissues. This inhibition blocks the conversion of arachidonic acid to prostaglandins, which are mediators of pain, fever and inflammation. Topical delivery concentrates the drug in the dermal and subdermal layers, achieving therapeutic concentrations at the target site while limiting systemic exposure.

Topical diclofenac may cause local and systemic adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Skin irritation: redness, itching or burning at the application site.
• Dryness: mild peeling or flaking of the skin.
• Pruritus: localized itching.
• Mild headache: occasional transient headache.

Serious or Rare Side Effects

• Severe allergic reaction: angioedema, urticaria or anaphylaxis requiring immediate medical attention.
• Contact dermatitis: intense rash or blistering beyond mild irritation.
• Systemic toxicity: gastrointestinal ulceration or bleeding, though rare with topical use.

• When using Motusol, observe the following precautions to ensure safe and effective therapy.
• Avoid application on broken or infected skin: limit use to intact epidermis.
• Do not cover treated area with occlusive dressings unless directed by a healthcare professional.
• Limit exposure to sunlight: avoid prolonged UV radiation on treated skin.
• Monitor for signs of systemic NSAID effects: gastrointestinal discomfort, cardiovascular symptoms.
• Pregnancy and lactation: consult a physician before use, as safety data are limited.
• Store below 25°C: keep in original container, protect from moisture and light.

Diclofenac sodium can interact with other medicines, altering its safety or effectiveness.

Major Interactions (Avoid)

• Anticoagulants (e.g., warfarin): increased risk of bleeding.
• Lithium: diclofenac may raise lithium serum levels, risking toxicity.
• Methotrexate: reduced clearance leading to enhanced toxicity.

Moderate Interactions (Monitor Closely)

• ACE inhibitors or ARBs: may diminish renal function, especially in volume‑depleted patients.
• Diuretics: potential for reduced kidney perfusion.
• Selective serotonin reuptake inhibitors (SSRIs): modestly increased bleeding risk.