Capsaicin, a vanillyl alkaloid found in hot peppers and related plants, is now available without a prescription as Zostrix-HP (GenDerm) for topical relief of pain due to diabetic neuropathy, herpes zoster, or arthritis. The new formulation contains 0.075% capsaicin; the drug was previously available in a 0.025% concentration as Zostrix.

The FDA has approved a topical 8% patch formulation of capsaicin (Qutenza – NeurogesX), available only by prescription, for local treatment of postherpetic neuralgia. Postherpetic neuralgia occurs after herpes zoster in about one third of patients ≥60 years old and can persist for months or even years.

A lidocaine 1.8% patch (ZTlido – Scilex) has been approved by the FDA for treatment of pain associated with postherpetic neuralgia (PHN). A lidocaine 5% patch (Lidoderm, and generics) was approved earlier for the same indication and has been used off-label for treatment of other types of localized pain. Both of these patches are available only by prescription. Lidocaine 4% patches (Aspercreme, IcyHot, and others) are available over the counter for back, neck, shoulder, and joint pain.

Duloxetine hydrochloride (Cymbalta - Lilly), a selective serotonin and norepinephrine reuptake inhibitor (SNRI) available for treatment of depression, has also been approved by the FDA for treatment of neuropathic pain associated with diabetic peripheral neuropathy (DPN). Duloxetine is one of two drugs approved specifically for management of neuropathic pain due to diabetes; the other, pregabalin (Lyrica - Pfizer), will be marketed soon and will be reviewed in the next issue of The Medical Letter.

The nonsteroidal anti-inflammatory drug (NSAID) diclofenac, has been approved by the FDA in a 1% topical gel formulation (Voltaren Gel - Endo) for treatment of osteoarthritis (OA). A 3% topical diclofenac gel (Solaraze) is currently approved for treatment of actinic keratoses, but not for topical use on joints. No other topical NSAIDs are approved by the FDA for OA. A diclofenac patch (Flector) was recently approved by the FDA for treatment of pain due to minor strains, sprains and contusions.

Pregabalin (Lyrica - Pfizer), a structural analog of gamma-aminobutyric acid (GABA) similar to gabapentin (Neurontin - Pfizer, and others), which recently became available generically, has been approved by the FDA for treatment of neuropathic pain associated with postherpetic neuralgia (PHN) and diabetic peripheral neuropathy (DPN), and for adjunctive treatment of partial onset seizures in adults with epilepsy.

Many different drugs are used for treatment of osteoarthritis pain, but none of them prevent progression of the disease. Nonpharmacologic approaches including weight management, exercise, tai chi, physical therapy, assistive devices, and total joint arthroplasty can also be used. The American College of Rheumatology (ACR) has published new guidelines for the management of osteoarthritis of the hip, hand, and knee.

Nonopioid drugs can be used in the treatment of many nociceptive and neuropathic pain conditions. For severe pain, especially severe chronic cancer pain, use of opioids may be necessary. Noninvasive nonpharmacologic treatments, including physical and psychological therapies, have been shown to improve pain and function in patients with some common chronic pain conditions and are unlikely to cause serious harms. A multimodal approach to analgesic therapy can increase pain control while reducing opioid use and adverse effects.

Cefprozil (Cefzil - Bristol-Myers Squibb), a new oral second-generation cephalosporin, was recently released in the USA for treatment of pharyngitis, bronchitis, otitis media, and skin and skin-structure infections.

The FDA has approved the subcutaneously injected interleukin (IL)-4 receptor alpha antagonist dupilumab (Dupixent – Sanofi/Regeneron) for treatment of eosinophilic esophagitis (EoE) in patients ≥12 years old who weigh ≥40 kg and treatment of prurigo nodularis in adults. Dupilumab is the first drug to be approved in the US for each of these indications. It is also FDA-approved for treatment of atopic dermatitis, asthma, and chronic rhinosinusitis with nasal polyposis.