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.

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.

Use of nonopioid drugs for pain was reviewed in a previous issue. For many types of moderate to severe acute pain, acetaminophen and/or an NSAID may be as effective as an opioid. Immediate-release formulations of full opioid agonists should generally be used for acute pain that is severe enough to require treatment with an opioid. Use of extended-release or long-acting opioid formulations initially and treatment durations >1 week have been associated with an increased risk of unintended long-term use.

Nonopioid drugs can be used in the treatment of many nociceptive and neuropathic pain conditions. Use of opioids for pain will be reviewed in a future issue.

Many different drugs are used for treatment of osteoarthritis pain, but none of them prevent progression of the disease. Many nonpharmacologic approaches are available as well, including weight management, exercise, physical therapy, assistive devices, and total joint arthroplasty. New guidelines for the management of osteoarthritis have recently been published.

Pain can be acute or chronic. The two major types of chronic pain are nociceptive pain and neuropathic pain. Nociceptive pain can be treated with nonopioid analgesics or opioids. Neuropathic pain is less responsive to opioids and is often treated with adjuvant drugs such as antidepressants and antiepileptics. Combining different types of analgesics may provide an additive analgesic effect without increasing adverse effects.

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.

Pain can be acute or chronic. Chronic pain has been broadly classified into two types: nociceptive and neuropathic. Nociceptive pain can be treated with nonopioid analgesics or opioids. Neuropathic pain is less responsive to opioids; adjuvant medicines such as antidepressants and anticonvulsants are often used to treat neuropathic pain. Combining different types of analgesics may provide an additive analgesic effect without increasing adverse effects.

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.

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.

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.