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 FDA has approved an agonist/antagonist combination of morphine and naltrexone (Embeda – King) for treatment of chronic moderate to severe pain requiring around-the-clock analgesia for an extended period of time. The addition of naltrexone is intended to prevent abuse of morphine.

Pain can be acute or chronic. Chronic pain has been broadly classified into two types: nociceptive and neuropathic. Nociceptive pain is generally treated with nonopioid analgesics and opioids. Antidepressants and anticonvulsants have been used to treat neuropathic pain. Combining two different types of analgesics may nprovide an additive analgesic effect without increasing adverse effects.

The Medical Letter review of Palladone (hydromorphone HCl) extended-release capsules (March 14, 2005) warned that a lethal dose could be released if the new formulation was taken with alcohol. Because of that risk, the FDA asked the manufacturer (Purdue) to withdraw the drug from the market (FDA News. July 13, 2005; FDC Reports – “The Pink Sheet” July 18, 2005; 67:3).

A once-daily extended-release (ER) oral formulation of the opioid analgesic hydromorphone hydrochloride (Palladone - Purdue Pharma) has been approved by the FDA for treatment of opioid-tolerant patients with persistent moderate to severe pain. Hydromorphone HCl, a semisynthetic congener of morphine and active metabolite of hydrocodone that has been used since the 1920s, is also available in immediate-release oral, injectable and suppository forms (Dilaudid, and others).

Three types of analgesic drugs are available: non-opioids, including aspirin, other nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen; opioids; and adjuvant drugs that are not usually thought of as analgesics, such as antidepressants, which can act as adjuvants when given with NSAIDs or opioids, or have analgesic activity of their own in some types of pain. Combining two different types of analgesics may provide an additive analgesic effect without necessarily increasing adverse effects.