Qutenza - Drug Monograph

Introduction

Qutenza (capsaicin) 8% patch is a novel topical analgesic system approved for the management of neuropathic pain. Unlike conventional systemic analgesics, Qutenza delivers a high concentration of capsaicin directly to the skin, providing prolonged pain relief through a unique mechanism of action. This localized treatment represents a significant advancement in neuropathic pain management with a favorable systemic safety profile.

Mechanism of Action

Qutenza contains synthetic capsaicin, a transient receptor potential vanilloid 1 (TRPV1) agonist. Capsaicin selectively binds to and activates TRPV1 receptors on nociceptive nerve fibers in the skin. This activation initially causes excitation of nociceptors, followed by defunctionalization of these pain fibers. The defunctionalization occurs through multiple mechanisms:

• Reversible impairment of nociceptor function
• Reduction in TRPV1 expression
• Decreased density of epidermal nerve fibers
• Inhibition of nociceptive signal transduction

This results in a prolonged reduction in pain sensitivity without affecting other sensory modalities or motor function. The effect typically lasts for approximately 3 months following a single application.

Indications

Qutenza is FDA-approved for:

• Management of neuropathic pain associated with postherpetic neuralgia (PHN)
• Management of neuropathic pain associated with diabetic peripheral neuropathy (DPN) of the feet

Dosage and Administration

• Apply to intact, dry, non-irritated skin
• Treatment area should not exceed 1000 cm² (approximately 4 patches)
• Treatment duration: 60 minutes for PHN, 30 minutes for DPN
• Repeat treatment every 3 months or as needed based on pain return

1. Pre-treat pain area with topical anesthetic 2. Cleanse application site with mild soap and water 3. Apply patches to cover painful area 4. Leave in place for prescribed duration 5. Remove patches and gently cleanse area 6. Apply cleansing gel provided in kit to remove residual capsaicin

• Hepatic impairment: No dosage adjustment required
• Renal impairment: No dosage adjustment required
• Elderly: No dosage adjustment required
• Pediatrics: Safety and effectiveness not established

Pharmacokinetics

Contraindications

• Hypersensitivity to capsaicin or any component of the patch system
• Application to broken or irritated skin
• Recent cardiovascular events (within 90 days)
• Uncontrolled hypertension

Warnings and Precautions

• Transient increases in blood pressure may occur during and shortly after treatment
• Monitor blood pressure during and for at least 1 hour after application

• Severe burning, pain, erythema, pruritus, and papules may occur
• Pre-treatment with topical anesthetic is recommended
• Proper handling techniques required for healthcare providers

• Temporary increase in pain during and immediately after application
• Rare cases of syncope reported

• Pregnancy: Category C - use only if potential benefit justifies potential risk
• Lactation: Exercise caution - unknown if excreted in human milk

Drug Interactions

• Concomitant application of other topical products may enhance absorption or cause skin irritation

• No clinically significant interactions with systemic medications reported
• May be used concomitantly with other neuropathic pain treatments

• Theoretical potential for interaction, but clinical significance unknown due to minimal systemic exposure

Adverse Effects

• Application site erythema
• Application site pain
• Application site pruritus
• Application site papules

• Application site edema
• Application site dryness
• Application site dermatitis
• Hypertension during application
• Nausea
• Headache

• Severe application site reactions
• Syncope
• Acute hypertension
• Second-degree burns (if improperly applied)

Monitoring Parameters

• Blood pressure every 15-30 minutes
• Pain assessment
• Skin reaction assessment

• Pain control assessment at 1-2 weeks and monthly thereafter
• Skin integrity at application site
• Blood pressure in patients with cardiovascular risk factors
• Assessment of treatment effectiveness every 3 months

Patient Education

• Expect temporary pain increase during and after treatment
• Arrange for transportation home after procedure
• Inform healthcare provider of all medications and medical conditions

• Avoid touching application site for several hours
• Do not expose treated area to direct heat (hot showers, heating pads)
• Do not cover treated area with tight clothing
• Contact healthcare provider if severe skin reactions occur
• Use cool compresses for discomfort if needed

• Track pain levels between treatments
• Report any changes in skin condition
• Schedule follow-up appointments every 3 months
• Do not attempt self-application

References

1. FDA Prescribing Information: Qutenza (capsaicin) 8% patch 2. Webster LR, et al. A multicenter, randomized, double-blind, controlled study of NGX-4010 for the treatment of postherpetic neuralgia. Pain Med. 2011;12(1):99-109. 3. Simpson DM, et al. Capsaicin 8% patch in painful diabetic peripheral neuropathy: a randomized, double-blind, placebo-controlled study. J Pain. 2017;18(1):42-53. 4. Backonja M, et al. NGX-4010 C117 Study Group. Efficacy and safety of NGX-4010, a high-concentration capsaicin patch, for the treatment of postherpetic neuralgia: a randomised, double-blind study. Lancet Neurol. 2008;7(12):1106-1112. 5. Derry S, et al. Topical capsaicin (high concentration) for chronic neuropathic pain in adults. Cochrane Database Syst Rev. 2017;1:CD007393. 6. Mick G, et al. Safety and tolerability of capsaicin 8% patch for peripheral neuropathic pain: pooled analysis from 11 clinical studies. Clin J Pain. 2019;35(2):161-173.