Capsaicin + Gabapentin + Ketoprofen + Methyl Salicylate

Usage

• Medical Conditions: This combination medication is prescribed for the topical relief of neuropathic pain, such as that caused by diabetic neuropathy, postherpetic neuralgia (shingles), and spinal cord injuries. It may also be used for musculoskeletal pain, such as joint, neck, back, and muscle pain.
• Pharmacological Classification: Analgesic, topical rubefacient, non-steroidal anti-inflammatory drug (NSAID), anticonvulsant.
• Mechanism of Action: This combination targets multiple pain pathways. Capsaicin depletes substance P, a neurotransmitter involved in pain transmission. Gabapentin modulates calcium channels in nerve cells and neurotransmitter release. Ketoprofen inhibits prostaglandin synthesis, reducing inflammation and pain. Methyl salicylate acts as a counterirritant, creating a warming sensation that distracts from pain.

Alternate Names

This medication is a combination of four generic drugs. It does not have a specific international nonproprietary name. It is known by various brand names depending on the manufacturer.

• Brand Names: Deep Senz, Femgesic Plus, Arigaba, Gabatrix, and others.

How It Works

• Pharmacodynamics: Capsaicin desensitizes nociceptors (pain receptors). Gabapentin modifies nerve signaling, likely via voltage-gated calcium channels. Ketoprofen inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin production. Methyl salicylate causes vasodilation, creating a sensation of warmth.

• Pharmacokinetics: This is a topical medication with limited systemic absorption. The extent of absorption depends on the specific formulation (cream, ointment, gel) and the application site. Metabolism and elimination information for each individual component are as follows:

  • Capsaicin: Metabolized in the liver, excreted in urine and feces.
  • Gabapentin: Primarily excreted unchanged in the urine.
  • Ketoprofen: Metabolized in the liver, excreted in urine.
  • Methyl Salicylate: Metabolized to salicylic acid, excreted in urine.

• Mode of Action: Capsaicin depletes substance P, a neurotransmitter involved in pain transmission. Gabapentin acts on the alpha-2-delta subunit of voltage-gated calcium channels, modulating neurotransmitter release. Ketoprofen inhibits COX-1 and COX-2 enzymes, reducing prostaglandin synthesis. Methyl salicylate activates TRPV1 receptors, creating a warming sensation.

• Elimination Pathways: See Pharmacokinetics above.

Dosage

This combination medication does not have standardized dosage guidelines across all clinical situations. The dosage depends on the specific product formulation and the patient’s condition. Always follow the prescribing doctor’s instructions.

Standard Dosage

Adults:

Apply a thin layer to the affected area as directed by the physician, typically 3-4 times daily.

Children:

Safety and efficacy in children have not been established. Use with caution under strict medical supervision, if necessary.

Special Cases:

Dosage adjustments may be required for elderly patients and those with renal or hepatic impairment. Consult the physician for individualized dosing recommendations.

Clinical Use Cases

The use of this combination in specific medical settings like intubation, surgical procedures, mechanical ventilation, ICU use, and emergency situations has not been established and is not recommended.

Dosage Adjustments

Dosage adjustments should be made on a case-by-case basis, considering the patient’s individual characteristics and comorbidities.

Side Effects

Common Side Effects

Application site reactions: burning, stinging, redness, itching, dryness, and irritation.

Rare but Serious Side Effects

Allergic reactions (rash, hives, itching, swelling, difficulty breathing), severe skin irritation.

Long-Term Effects

Potential for skin thinning with prolonged use of topical corticosteroids.

Adverse Drug Reactions (ADR)

Allergic reactions requiring urgent medical attention.

Contraindications

• Hypersensitivity to any component of the medication.
• Open wounds, broken skin, or infected areas.
• Severe hepatic or renal impairment.

Drug Interactions

• Topical medications: Avoid concomitant use of other topical analgesics, corticosteroids, or anesthetics on the same area.
• Oral NSAIDs: Concurrent use may increase the risk of gastrointestinal side effects.
• Anticoagulants/antiplatelets: Ketoprofen may increase the risk of bleeding.

Pregnancy and Breastfeeding

• Pregnancy: Consult a physician before use. Use only if the potential benefit outweighs the risk to the fetus.
• Breastfeeding: Consult a physician before use. It is unknown whether these drugs pass into breast milk.

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: Monitor for application site reactions and signs of systemic absorption.

Popular Combinations

This combination itself is a popular combination for topical pain relief.

Precautions

• Avoid contact with eyes, mucous membranes, and broken skin.
• Wash hands thoroughly before and after application.
• Monitor for allergic reactions.

FAQs (Frequently Asked Questions)

Q1: What is the recommended dosage for Capsaicin + Gabapentin + Ketoprofen + Methyl Salicylate?

A: The dosage varies depending on the product and patient. Follow the physician’s instructions. Typically, apply a thin layer to the affected area 3-4 times daily.

Q2: Can this combination be used in children?

A: Safety and efficacy in children have not been established. Use with caution under strict medical supervision, if necessary.

Q3: What are the common side effects?

A: Common side effects include application site reactions such as burning, stinging, redness, itching, and dryness.

Q4: Are there any drug interactions I should be aware of?

A: Avoid concomitant use of other topical analgesics, corticosteroids, or anesthetics. Inform your physician about all medications you are taking, including oral NSAIDs and anticoagulants.

Q5: Can I use this medication if I am pregnant or breastfeeding?

A: Consult your physician before use during pregnancy or breastfeeding.

Q6: What should I do if I accidentally get this medication in my eyes?

A: Rinse immediately with plenty of water and seek medical advice if irritation persists.

Q7: Can I apply this medication to open wounds?

A: No, do not apply to open wounds, broken skin, or infected areas.

Q8: How long can I use this medication?

A: Use as directed by your physician. They will determine the appropriate duration of treatment.

Q9: Can I use this medication with other pain relievers?

A: Inform your physician about all other pain medications you are taking, including over-the-counter medications, to avoid potential drug interactions. It is generally advisable to avoid concomitant use of oral NSAIDs.