What are the recommended topical pain compounds for pain management?

Topical Pain Compounds for Pain Management

For neuropathic pain, capsaicin 8% patch is the strongest recommendation, providing pain relief for up to 12 weeks with a single 30-minute application, and should be your first-line topical agent. 1

Neuropathic Pain

First-Line: Capsaicin

• Capsaicin 8% dermal patch or cream is strongly recommended for chronic neuropathic pain (including HIV-associated peripheral neuropathy and postherpetic neuralgia) with high-quality evidence 1
• Apply for 30 minutes at the site of pain; provides relief for at least 12 weeks 1
• Pre-treat with 4% lidocaine for 60 minutes before capsaicin application, then wipe off the lidocaine - this prevents the common side effects of erythema and pain from capsaicin 1
• Lower concentration capsaicin (0.025-0.075%) can be applied 3-4 times daily for 6 weeks, though evidence is more limited 1
• Warn patients about initial burning/stinging sensations that typically subside with continued use 1, 2

Second-Line: Lidocaine

• Lidocaine patches (4-5%) are recommended for neuropathic pain, though evidence is limited compared to capsaicin 1, 2
• Can be cut to fit affected areas; up to 3 patches may be used simultaneously for broader coverage 2
• Provides effective pain relief with minimal systemic absorption 2

Musculoskeletal Pain (Osteoarthritis, Sprains, Strains)

First-Line: Topical NSAIDs

• Topical diclofenac is the most effective topical NSAID with the strongest evidence 1, 2
• Diclofenac Emulgel® formulation has an NNT of 1.8 (95% CI 1.5-2.1) for at least 50% pain reduction - the lowest NNT of any topical compound 3, 4
• Diclofenac gel/patch provides small to moderate benefits for osteoarthritis pain at 3-6 months, with intermediate-term evidence at 6-12 months 1
• For single or few joints near the skin surface (e.g., knee), topical NSAIDs are specifically recommended over systemic options 1

Alternative Topical NSAIDs

• Ketoprofen gel has an NNT of 2.5 (95% CI 2.0-3.4) for clinical success 3, 5
• Ibuprofen gel has an NNT of 3.9 (95% CI 2.7-6.7) 3
• Topical NSAIDs should be used at the lowest effective dosage and shortest duration 1

When to Use Topical vs. Systemic NSAIDs

• Use topical NSAIDs first when pain is localized to accessible joints 1, 2
• Switch to systemic NSAIDs or duloxetine when multiple joints are affected or topical NSAIDs provide incomplete relief 1
• Topical NSAIDs have a more favorable safety profile than oral NSAIDs due to low serum concentrations, making them particularly appropriate for older adults and those with cardiovascular, renal, or gastrointestinal comorbidities 1, 6

Fibromyalgia

• Topical diclofenac is associated with small to moderate improvements in pain, function, and quality of life in fibromyalgia 1
• Consider as part of multimodal therapy alongside systemic agents 1

Compounded Topical Formulations

Amitriptyline-Ketamine Compound

• Can be applied to affected areas up to 3 times daily 1, 2
• 75% of patients showed improvement in pain in some studies 2
• May add clonidine, gabapentin, or lidocaine to the compound (up to 5 ingredients total), though evidence is anecdotal 1

Other Compounded Options

• Gabapentin 6% ointment (limited evidence) 1
• Clonidine transdermal patches (0.1-0.3 mg daily) offer weekly applications and can be placed anywhere on the body 1

Safety Profile

Local Adverse Events

• Local skin reactions with topical NSAIDs are generally mild and transient, occurring in approximately 4-14% of users, and do not differ significantly from placebo 3, 5, 4
• Capsaicin commonly causes erythema and pain at application site, which can be mitigated with lidocaine pre-treatment 1

Systemic Adverse Events

• Systemic adverse events with topical NSAIDs are very rare and similar to placebo 3, 5
• All NSAID formulations (topical and oral) carry the same FDA boxed warnings regarding cardiovascular and renal toxicity, but topical formulations achieve much lower serum concentrations 6

Clinical Pitfalls

• Avoid ice and water immersion of extremities, or limit to 10 minutes at a time and 4 times daily maximum - prolonged cold exposure can cause tissue damage 1
• Acetaminophen has limited evidence for effectiveness in osteoarthritis and is no longer considered first-line 1
• Capsaicin patches 8% cannot be applied to open skin lesions - wait until herpetic lesions have healed before applying 7
• Evidence for topical NSAIDs in neck and low back pain is less established than for osteoarthritis 2, 7