Role of Capsaicin Cream in Managing Neuropathic Pain
Capsaicin is a third-line treatment for neuropathic pain, with high-concentration (8%) capsaicin patch showing better efficacy than low-concentration (0.075%) cream formulations for specific neuropathic pain conditions. 1, 2
Formulations and Efficacy
High-Concentration Capsaicin (8% Patch)
- The 8% capsaicin patch is applied for 30-60 minutes under medical supervision with pain relief lasting up to 90 days 2
- A single application can provide sustained pain reduction from the second week through 8-12 weeks 1
- Results from phase 3 trials in postherpetic neuralgia (PHN) showed efficacy with a single application compared to low-concentration control patches 1
- For HIV-associated neuropathic pain, high-concentration capsaicin (8%) demonstrated efficacy with 31% of patients experiencing >30% mean reduction in pain compared to 14% with control 2
- Application requires pretreatment with topical lidocaine (4%) for 60 minutes to reduce application-related discomfort 2
Low-Concentration Capsaicin (0.075% Cream)
- Low-concentration capsaicin cream is applied 3-4 times daily to affected areas for 6 weeks 2
- Evidence for low-concentration capsaicin is less robust, with Cochrane reviews suggesting limited efficacy beyond placebo 3
- A 1997 study showed that 0.075% capsaicin cream decreased postsurgical neuropathic pain with an average pain reduction of 53% versus 17% for placebo 4
Specific Neuropathic Pain Conditions
Postherpetic Neuralgia (PHN)
- High-concentration (8%) capsaicin patch showed about 10% more participants reporting significant improvement at 8 and 12 weeks compared to control 5
- Application was safe and well-tolerated with adverse events limited to transient increases in pain and application site reactions 1
HIV-Associated Neuropathy
- One of two RCTs showed significantly decreased pain continuing from the second week after treatment through 12 weeks 1
- About 10% more patients had average 2-12 week pain intensity reductions of at least 30% with capsaicin than control 5
Diabetic Peripheral Neuropathy
- The American Diabetes Association recommends topical treatments like capsaicin for localized pain in diabetic neuropathy 2
- Capsaicin is recommended when patients have contraindications to oral therapy or prefer topical treatments 2
Chemotherapy-Induced Peripheral Neuropathy
- Recent research suggests capsaicin 8% patch may not only provide pain relief but potentially lead to regeneration and restoration of sensory nerve fibers 6
Treatment Algorithm
- For localized neuropathic pain, consider high-concentration capsaicin (8% patch) applied for 30-60 minutes under medical supervision 2
- For areas not amenable to patch application or when high-concentration patch is unavailable, low-concentration (0.075%) capsaicin cream applied 3-4 times daily may be considered, though efficacy is less established 2, 3
- For inadequate response, consider combining with other neuropathic pain medications such as gabapentinoids, SNRIs, or tricyclic antidepressants 2, 7
- High-concentration patch can be reapplied after 90 days if pain returns 2
Adverse Effects and Precautions
- Most common adverse effect is local skin irritation, including burning sensation, erythema, and application site reactions 1
- Initial burning sensation typically resolves with continued use 2
- Skin biopsy studies have shown transient epidermal denervation by capsaicin paralleled by functional loss, particularly of heat pain sensation 1
- Long-term safety of repeated applications of high-concentration capsaicin requires careful evaluation 1
Clinical Pearls
- Warn patients about the initial burning sensation to improve adherence 2
- Consider pretreatment with topical lidocaine before high-concentration capsaicin application 2
- Patients may need additional pain management during application, such as short-term analgesics 2
- Avoid excessive cooling of affected areas after application 2
- Capsaicin works by binding to TRPV1 receptors, decreasing the release of pain neurotransmitters like substance P 2