1. Clinical Overview
A fixed-dose combination topical analgesic and anti-inflammatory agent. Choline Salicylate is a non-steroidal anti-inflammatory drug (NSAID) derivative of salicylic acid, providing anti-inflammatory and analgesic effects. Lidocaine is a local anesthetic (amide type) that provides rapid pain relief by blocking sodium channels in nerve fibers. The combination offers a synergistic effect for topical pain management, with the anti-inflammatory action of choline salicylate complementing the anesthetic action of lidocaine.
| Onset | Duration | Bioavailability |
|---|---|---|
| Lidocaine: 3-5 minutes; Choline Salicylate: 15-30 minutes for anti-inflammatory effect. | Lidocaine: 1-2 hours; Choline Salicylate: 4-6 hours (topical). | Topical: Variable and low (<10% for choline salicylate, <3% for lidocaine through intact skin). Depends on site, skin condition, and application method. |
2. Mechanism of Action
The combination works via two distinct mechanisms. Lidocaine blocks voltage-gated sodium channels on neuronal membranes, inhibiting the initiation and conduction of nerve impulses, leading to reversible local anesthesia. Choline Salicylate, after conversion to salicylic acid, inhibits the cyclooxygenase (COX) enzymes, particularly COX-1 and COX-2, thereby reducing the synthesis of prostaglandins, which are mediators of pain, inflammation, and fever at the site of application.
3. Indications & Uses
- Topical relief of pain and inflammation in acute musculoskeletal conditions (e.g., sprains, strains, tendonitis)
- Symptomatic relief in osteoarthritis of superficial joints (e.g., knees, elbows)
- Localized pain relief in non-articular rheumatism (e.g., fibrositis, myalgia)
4. Dosage & Administration
Adult Dosage: Apply a thin layer to the affected area 3 to 4 times daily. Do not exceed 4 applications per day. The amount should be sufficient to cover the area without excessive rubbing.
Administration: Apply to clean, dry, intact skin. Gently rub in until absorbed. Wash hands immediately after application unless treating hands. Do not apply with occlusive dressings unless advised by a doctor. Do not use with heating pads. Avoid contact with eyes and mucous membranes.
5. Side Effects
Common side effects may include:
- Localized skin reactions: itching, burning, stinging, erythema (redness) at application site
- Dryness or scaling of skin
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Anticoagulants (Warfarin, Acenocoumarol) | Increased risk of bleeding due to antiplatelet effect of salicylate | Major |
| Other NSAIDs (Oral: Ibuprofen, Diclofenac) | Increased risk of GI toxicity and reduced anti-inflammatory effect | Moderate |
| Methotrexate | Salicylates can decrease renal clearance of methotrexate, increasing toxicity risk | Major |
| Sulfonylureas (Glibenclamide, Glimepiride) | Salicylates may potentiate hypoglycemic effect | Moderate |
| ACE Inhibitors (Enalapril, Ramipril) | Salicylates may reduce antihypertensive efficacy | Moderate |
| Antiarrhythmics (Mexiletine) | Additive cardiac effects with lidocaine; increased toxicity risk | Major |
| Beta-blockers (Propranolol) | May increase lidocaine levels by reducing hepatic blood flow | Moderate |
7. Patient Counselling
- DO apply only to clean, dry, intact skin.
- DO wash hands before and after application.
- DO use only as directed by the physician, 3-4 times daily.
- DON'T apply to open wounds, broken skin, eyes, nose, mouth, or genital areas.
- DON'T use with heating pads, bandages, or occlusive dressings unless advised.
- DON'T exceed the recommended dose or area of application.
- DON'T use in children under 16 without consulting a doctor.
8. Toxicology & Storage
Overdose: Topical Overuse: Systemic salicylate toxicity (tinnitus, vertigo, headache, confusion, hyperventilation, metabolic acidosis, hyperthermia, coma). Lidocaine toxicity (perioral numbness, metallic taste, dizziness, tinnitus, blurred vision, tremors, seizures, respiratory depression, bradycardia, cardiac arrest). Local: Severe skin irritation, blistering.
Storage: Store at room temperature (15-30°C). Protect from light and moisture. Keep the tube tightly closed. Keep out of reach of children and pets. Do not freeze.