Nefopam, sold under the brand name Acupan among others, is a centrally acting, non-opioid analgesic medication, with stimulant and sympathomimetic properties that is primarily used to treat moderate to severe pain.

Nefopam is based on a benzoxazocine compound. It was developed in the 1960s and marketed under the name fenazocine. It was initially used in shivering, as a muscle relaxant and as an antidepressant, but then increasingly as an analgesic.

Nefopam was significantly more effective than aspirin as an analgesic in one clinical trial, although with a greater incidence of side effects such as sweating, dizziness and nausea, especially at higher doses.

The estimated relative potency of nefopam to morphine indicates that 20 mg of nefopam HCl is the approximate analgesic equal of 12 mg of morphine with comparable analgesic efficacy to morphine, or oxycodone. Nefopam tends to produce fewer side effects, does not produce respiratory depression, and has much less abuse potential, and so is useful either as an alternative to opioid analgesics, or as an adjunctive treatment for use alongside opioids or other types of analgesics.

A 2025 review, covering 17 studies, found that nefopam was an effective adjunctive postoperative analgesic with benefits in pain management, and correlated with a mean decrease in opioid consumption across the studies of 38%. Adverse effects were not discussed in detail in the included studies.

For chronic pain nefopam may sometimes be used when common alternatives are contraindicated or ineffective, or as an add-on therapy.

Nefopam is used to treat severe hiccups.

Nefopam is thought to have some efficacy for treating (off-label) Parkinson's disease, in a similar fashion to those of Bupropion and Methylphenidate.