Nefopam is a centrally-acting but non-opioid analgesic

Analgesic

An analgesic is any member of the group of drugs used to relieve pain . The word analgesic derives from Greek an- and algos ....

 drug

Drug

A drug, broadly speaking, is any substance that, when absorbed into the body of a living organism, alters normal bodily function. There is no single, precise definition, as there are different meanings in drug control law, government regulations, medicine, and colloquial usage.In pharmacology, a...

 of the benzoxazocine chemical class which was developed by Riker Laboratories in the 1960s. It is widely used, mainly in Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

an countries, for the relief of moderate to severe pain as an alternative to opioid

Opioid

An opioid is a psychoactive chemical that works by binding to opioid receptors, which are found principally in the central and peripheral nervous system and the gastrointestinal tract...

 analgesic drugs. Animal studies have shown that nefopam has a potentiating (analgesic-sparing) effect on morphine and other opioids by broadening the antinociceptive action of the opioid and possibly other mechanisms, generally lowering the dose requirements of both when they are used concomitantly.

Use

Nefopam has additional action in the prevention of shivering, which may be a side effect of other drugs used in surgery.

Nefopam at a dose of 30–120 mg is significantly more effective than aspirin

Aspirin

Aspirin , also known as acetylsalicylic acid , is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. It was discovered by Arthur Eichengrun, a chemist with the German company Bayer...

 as an analgesic, although with a greater incidence of side effects such as sweating, dizziness and nausea, especially at higher doses.

Nefopam is around half the potency and slightly less effective as an analgesic compared to morphine

Morphine

Morphine is a potent opiate analgesic medication and is considered to be the prototypical opioid. It was first isolated in 1804 by Friedrich Sertürner, first distributed by same in 1817, and first commercially sold by Merck in 1827, which at the time was a single small chemists' shop. It was more...

, or oxycodone

Oxycodone

Oxycodone is an opioid analgesic medication synthesized from opium-derived thebaine. It was developed in 1916 in Germany, as one of several new semi-synthetic opioids in an attempt to improve on the existing opioids: morphine, diacetylmorphine , and codeine.Oxycodone oral medications are generally...

, but tends to produce fewer side effects, does not produce respiratory depression, and has much less abuse

Drug abuse

Substance abuse, also known as drug abuse, refers to a maladaptive pattern of use of a substance that is not considered dependent. The term "drug abuse" does not exclude dependency, but is otherwise used in a similar manner in nonmedical contexts...

 potential, and so is useful either as an alternative to opioids, or as an adjunctive treatment for use alongside opioid(s) or other analgesics.

Nefopam is also used to combat severe hiccups.

Pharmacology

The mechanism of action of nefopam is not well understood, although inhibition of serotonin

Serotonin

Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...

, dopamine

Dopamine

Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...

 and noradrenaline reuptake

Reuptake

Reuptake, or re-uptake, is the reabsorption of a neurotransmitter by a neurotransmitter transporter of a pre-synaptic neuron after it has performed its function of transmitting a neural impulse....

 is thought to be involved in its analgesic effects, and there may be other modes of action such as through histamine H3 receptors and glutamate. Recently, like its analogue orphenadrine

Orphenadrine

Orphenadrine is an anticholinergic drug of the ethanolamine antihistamine class with prominent CNS and peripheral actions used to treat painful muscle spasms, other similar conditions, as well as the treatment...

 which also has analgesic effects, nefopam has been found to act as a voltage-gated sodium channel blocker

Sodium channel blocker

Sodium channel blockers are agents that impair conduction of sodium ions through sodium channels.-Extracellular:The following naturally produced substances block sodium channels by binding to and occluding the extracellular pore opening of the channel:...

, and this may in part or fully mediate its antinociceptive effects.

Recreational Use/Overdose

Recreational use of nefopam and death from overdose have both been reported, although these events are less common with nefopam than with opioid analgesic drugs.