Usage
This combination medication, available as a topical gel, is prescribed for the relief of pain and inflammation associated with musculoskeletal and joint disorders. These include:
- Mild to moderate muscle pain
- Sprains and strains
- Bruises
- Soft tissue rheumatism
- Arthritis
- Backaches
- Fibrositis
- Lumbago
- Sciatica
- Stiff neck
- Tennis elbow
- Rheumatic pain
Pharmacological Classification: This topical gel is classified as a non-steroidal anti-inflammatory drug (NSAID) combined with a local anesthetic, counterirritants, and penetration enhancers.
Mechanism of Action: This combination targets pain and inflammation through multiple pathways:
- Diclofenac diethylamine: Inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin synthesis. This, in turn, decreases pain and inflammation.
- Lidocaine: A local anesthetic, blocks nerve signals, providing additional pain relief.
- Linseed Oil: Facilitates diclofenac’s penetration through the skin. Its omega-3 fatty acids offer anti-inflammatory benefits.
- Methyl Salicylate: Acts as a counterirritant, producing a warming sensation that distracts from deeper pain. It also possesses anti-inflammatory properties.
- Menthol: Creates a cooling sensation, acting as another counterirritant, further enhancing pain relief by stimulating cold receptors and dilating blood vessels.
Alternate Names
Diclofenac diethylamine + Lidocaine + Linseed Oil + Menthol + Methyl Salicylate is sometimes referred to as Diclofenac Diethylamine/lidocaine/linseed oil/menthol/methyl salicylate topical. Various brand names exist depending on the manufacturer and region, including Rafdonac-Ultra Gel.
How It Works
Pharmacodynamics:
- Diclofenac, the primary analgesic and anti-inflammatory component, acts by inhibiting COX-1 and COX-2 enzymes, thereby suppressing prostaglandin synthesis.
- Lidocaine provides local anesthetic action by blocking voltage-gated sodium channels in neuronal membranes.
- Methyl salicylate and menthol exert their counterirritant effects through activation of TRP channels, leading to sensations of warmth and coolness, respectively. They also have mild anti-inflammatory properties.
Pharmacokinetics:
- Diclofenac is absorbed systemically through the skin, albeit in low amounts when applied topically.
- The liver primarily metabolizes it, and the kidneys excrete the metabolites. The metabolism and elimination pathways are similar to those of oral diclofenac.
- Lidocaine is also absorbed through the skin, but significant systemic absorption is uncommon with topical application.
- Methyl salicylate and menthol are minimally absorbed systemically.
Receptor Binding, Enzyme Inhibition, or Neurotransmitter Modulation:
- Diclofenac primarily inhibits COX-1 and COX-2 enzymes.
- Lidocaine interacts with voltage-gated sodium channels.
- Methyl salicylate and menthol modulate TRP channels.
Elimination Pathways:
- Diclofenac is primarily eliminated via hepatic metabolism followed by renal excretion.
- Lidocaine is metabolized in the liver and excreted by the kidneys.
Dosage
Standard Dosage
Adults:
Apply a thin layer to the affected area 3-4 times daily, rubbing gently until it disappears. The amount should correspond to a 2-4 gram dose or a 4-8cm band if the tube opening is fully open.
Children:
Use in children below 12 years of age is contraindicated. For adolescents over 12, consult a pediatrician. Some sources indicate it is safe for children above 2 years of age, but caution is advised, especially in children aged 2-12 years, particularly with conditions like viral flu, chickenpox, or viral fever due to the risk of Reye’s Syndrome associated with methyl salicylate.
Special Cases:
- Elderly Patients: The usual adult dosage may generally be used, but it’s essential to monitor for adverse effects carefully.
- Patients with Renal Impairment: Caution is advised; dosage adjustment might be necessary.
- Patients with Hepatic Dysfunction: Caution is advised; dosage adjustment might be necessary.
- Patients with Comorbid Conditions: Individualized assessment is crucial. Particular caution is warranted for patients with asthma, cardiovascular disease, or gastrointestinal issues.
Clinical Use Cases
This medication is not typically used in clinical settings such as intubation, surgical procedures, mechanical ventilation, ICU, or emergency situations. Its primary indication is localized musculoskeletal pain.
Dosage Adjustments
Dosage adjustments are generally not required except in specific cases mentioned above. Always adhere to the prescribing physician’s recommendations.
Side Effects
Common Side Effects:
- Itching
- Irritation
- Redness
- Burning sensation at the application site
- Dry skin
- Rash
Rare but Serious Side Effects:
- Allergic reactions (e.g., hives, difficulty breathing, swelling of the face, lips, tongue, or throat)
- Severe skin reactions (e.g., blistering, peeling)
Long-Term Effects:
Prolonged use can potentially lead to skin thinning or other skin changes.
Adverse Drug Reactions (ADR):
Severe allergic reactions or significant skin irritation necessitate immediate medical attention.
Contraindications
- Hypersensitivity to any component of the formulation.
- Aspirin-induced asthma or allergic reactions to other NSAIDs.
- Third trimester of pregnancy.
- Open wounds or broken skin.
Drug Interactions
- Topical salicylates may potentiate the anticoagulant effect of warfarin.
- Menthol may decrease the effectiveness of warfarin when taken orally.
- Potential interactions with other topical medications exist.
- May interact with oral painkillers (aspirin), anticoagulants (warfarin), anti-rheumatoid drugs (methotrexate), and immunosuppressants (cyclosporine).
Pregnancy and Breastfeeding
Use during pregnancy, especially the third trimester, is contraindicated. Use during breastfeeding should be approached with caution and only when the benefits clearly outweigh the potential risks. Consult a physician for guidance. Safety during pregnancy and lactation hasn’t been fully established.
Drug Profile Summary
- Mechanism of Action: See above.
- Side Effects: See above.
- Contraindications: See above.
- Drug Interactions: See above.
- Pregnancy & Breastfeeding: See above.
- Dosage: See above.
- Monitoring Parameters: Observe for local skin reactions and systemic effects.
Popular Combinations
This combination itself is a commonly used formulation, incorporating an analgesic, anesthetic, penetration enhancer, and two counterirritants to address pain via various mechanisms.
Precautions
- General Precautions: Pre-screening for allergies and assessing liver and kidney function is essential.
- Specific Populations: See sections on children, elderly, renal/hepatic impairment, pregnancy, and breastfeeding.
- Lifestyle Considerations: Limit sun exposure during treatment. Caution with alcohol due to the risk of increased gastrointestinal bleeding.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Diclofenac diethylamine + Lidocaine + Linseed Oil + Menthol + Methyl Salicylate?
A: Adults and children over 14: Apply a thin layer to the affected area 3-4 times daily, rubbing gently until absorbed. Consult a pediatrician for use in children over 12.
Q2: Can this gel be used during pregnancy?
A: It is contraindicated during the third trimester. Use during the first and second trimesters should be under strict medical supervision and only if the benefits outweigh the risks.
Q3: What are the common side effects?
A: Common side effects include itching, irritation, redness, burning sensation, dryness, and rash at the application site.
Q4: Are there any serious side effects I should be aware of?
A: Rarely, severe allergic reactions or severe skin reactions can occur. Seek immediate medical attention if these develop.
Q5: Can I use this gel on open wounds?
A: No, application to open wounds or broken skin is contraindicated.
Q6: What should I do if the gel gets in my eyes?
A: Rinse thoroughly with plenty of clean water.
Q7: Can I use a heating pad after applying the gel?
A: No, avoid applying heat to the treated area.
Q8: How long can I use this gel?
A: Do not use for more than 14 days unless advised by a doctor. If symptoms don’t improve or worsen within 7 days, consult a physician.
Q9: Can I use this gel if I am breastfeeding?
A: Consult a physician. Use with caution only if the benefits outweigh the potential risks to the infant.
Q10: What should I do if I accidentally ingest the gel?
A: Seek immediate medical attention.
