A-Fenac Plus

A. Approved Indications

• Musculoskeletal and Joint Disorders:
• Localized pain and inflammation in osteoarthritis, rheumatoid arthritis
• Periarticular inflammation (e.g., tendinitis, bursitis)
• Post-traumatic and Postoperative Pain:
• Sprains, strains, contusions
• Minor surgical and dental procedures (topical or injectable form)
• Localized Neuropathic or Nociceptive Pain:
• Myofascial pain, cervical and lumbar radiculopathy
• Post-herpetic neuralgia (topical)

B. Clinically Accepted Off-label Uses

• Local anesthesia during minor dermatologic procedures (injectable lidocaine + diclofenac formulation)
• Muscular trigger point pain relief (injections under trained supervision)

Route of Administration:

• Topical Gel/Cream (most common)
• Parenteral (Lidocaine + Diclofenac in some regional blocks)

Adults:

• Topical Gel/Cream:
• Apply 2–4 grams to affected area 3–4 times daily.
• Massage gently into the skin until absorbed.
• Do not apply to broken or irritated skin.
• Injection (Professional Use Only):
• Dose based on clinical indication and anatomical location.
• Lidocaine (usually 1–2%) is injected with a small volume of diclofenac sodium under expert supervision.
• Maximum safe dose of lidocaine should not exceed 4.5 mg/kg (without epinephrine).

Pediatrics:

• Not recommended for children under 12 years (topical).
• Parenteral use not recommended without pediatric pain specialist supervision.

Elderly:

• Start with lowest effective dose.
• Monitor for systemic side effects, especially in frail patients.

Renal/Hepatic Impairment:

• Use with caution.
• Avoid large area application or repeated injections due to risk of accumulation.

Diclofenac Sodium is a non-selective NSAID that inhibits cyclooxygenase (COX-1 and COX-2), reducing prostaglandin synthesis involved in inflammation and pain.
Lidocaine Hydrochloride is a local amide-type anesthetic that blocks voltage-gated sodium channels in neuronal membranes, preventing initiation and conduction of nerve impulses, resulting in localized numbness.
The combination provides dual-action relief—diclofenac reduces inflammation and deeper pain signaling, while lidocaine offers immediate surface and nerve-ending analgesia, making it particularly effective for localized musculoskeletal and neuropathic pain.

Topical Formulation:

• Absorption: Limited systemic absorption; varies with surface area and integrity of skin.
• Onset: Lidocaine acts within minutes; diclofenac within 30–60 minutes.
• Distribution: Lidocaine binds ~65% to plasma proteins; diclofenac >99%.
• Metabolism:
• Lidocaine: Metabolized in liver by CYP1A2 and CYP3A4 to active and inactive metabolites.
• Diclofenac: Metabolized by CYP2C9 in the liver.
• Excretion:
• Lidocaine: Renal (~90% as metabolites)
• Diclofenac: Renal and biliary
• Half-life:
• Lidocaine: ~1.5–2 hours (systemic)
• Diclofenac: ~1–2 hours

• Pregnancy:
• Diclofenac: Avoid during 3rd trimester (Category D) due to risk of premature ductus arteriosus closure.
• Lidocaine: Category B; crosses placenta but generally safe in small doses when used topically or locally.
• Lactation:
• Lidocaine and diclofenac are excreted in small amounts in breast milk.
• Avoid applying near breast; use caution, especially for repeated or large-area use.
• Summary: Use during pregnancy/lactation only if clearly indicated and under medical supervision.

• Primary Class: Topical Analgesic and Anti-inflammatory
• Subclasses:
• NSAID (Diclofenac Sodium)
• Local Anesthetic (Lidocaine Hydrochloride)

• Hypersensitivity to diclofenac, lidocaine, or related compounds (NSAIDs or amide anesthetics)
• Broken, infected, or inflamed skin (for topical use)
• History of NSAID-induced asthma or urticaria
• Severe hepatic, renal, or cardiac impairment (for systemic use)
• Complete heart block or severe sinoatrial dysfunction (injectable lidocaine)

• Topical Overuse: Risk of systemic NSAID effects if used over large areas or long duration.
• Cardiovascular Caution: NSAIDs like diclofenac may increase cardiovascular risk in high doses or long-term use.
• CNS Effects: High systemic lidocaine levels may cause dizziness, confusion, or seizures.
• Methemoglobinemia: Rarely reported with lidocaine—monitor if high doses used.
• Avoid Occlusion: Do not use under occlusive dressings unless advised.

Common (Topical):

• Local burning, stinging, redness
• Mild skin irritation or itching
• Dryness or flaking

Less Common:

• Allergic contact dermatitis
• Dizziness or drowsiness (from systemic lidocaine absorption)
• Nausea or gastrointestinal discomfort (diclofenac-related)

Rare/Serious:

• Anaphylaxis
• Stevens-Johnson Syndrome (NSAID-related)
• Seizures, cardiac arrhythmias (lidocaine toxicity)
• GI bleeding (if systemic NSAID exposure occurs)

• Topical Use: Minimal interaction unless large systemic absorption occurs.
• NSAIDs or Anticoagulants: Additive GI bleeding risk with systemic diclofenac.
• Antiarrhythmics (e.g., amiodarone): May enhance lidocaine’s cardiodepressant effects.
• CYP Interactions:
• CYP2C9 (diclofenac): Inhibitors may increase diclofenac levels.
• CYP3A4/CYP1A2 (lidocaine): Inhibitors (e.g., erythromycin, cimetidine) may elevate lidocaine levels.

• FDA and EMA: Continue to emphasize limiting systemic NSAID exposure due to cardiovascular and GI risks—even with topical forms.
• Topical Diclofenac Guidelines (e.g., NICE): Recommended for localized osteoarthritis pain, especially in elderly to avoid systemic effects.
• Lidocaine Safety: EMA advises safe use of lidocaine within dosing limits; no recent restriction updates.

• Temperature: Store at 20°C to 25°C (68°F to 77°F)
• Humidity: Keep away from moisture; close cap tightly
• Light Protection: Store in original packaging away from direct light
• Handling:
• For external use only (topical)
• Keep out of reach of children
• Do not apply near eyes or mucous membranes
• Shelf-life: Use within expiry date on label. Discard if product becomes discolored or changes texture.