|Systematic (IUPAC) name|
|Trade names||Marezine, Valoid, Nausicalm|
|Pregnancy cat.||A (AU)|
|Legal status||Pharmacist Only (S3) (AU) POM (UK) OTC (Netherlands)|
|Routes||Oral, IM, IV|
|Metabolism||N-demethylated to inactive norcyclizine|
|Mol. mass||266.381 g/mol|
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Cyclizine is an antihistamine drug used to treat nausea, vomiting and dizziness associated with motion sickness, vertigo and post-operatively following administration of general anaesthesia and opioids.
Nausea, vomiting and dizziness associated with motion sickness, vertigo and post-operatively following administration of general anaesthesia and opioids. It is sometimes given in hyperemesis gravidarum, although the manufacturer advises that it be avoided in pregnancy. Off-licence use often occurs with specialists in hospitals to treat inpatients who have become severely dehydrated in pregnancy. An off-label use is as an opioid/opiate potentiator.
Adverse effects 
Rare – Hypersensitivity reactions (bronchospasm, angioedema, anaphylaxis, rashes and photosensitivity reactions), extrapyramidal effects, dizziness, confusion, depression, sleep disturbances, tremor, liver dysfunction and hallucinations
As cyclizine hydrochloride 50 mg tablets and cyclizine lactate solution for intramuscular or intravenous injection (brand names: Valoid in UK and Marezine, Marzine and Emoquil in US). Cyclizine HCl 25 mg is marketed as Bonine for Kids in the US.
Cyclizine is a piperazine derivative with histamine H1-receptor antagonist (antihistamine) activity. The precise mechanism of action in inhibiting the symptoms of motion sickness is not well understood. It may have effects directly on the labyrinthine apparatus and on the chemoreceptor trigger zone. Cyclizine exerts a central anticholinergic (antimuscarinic) action.
Cyclizine was developed in the American division of pharmacy company Burroughs Wellcome (today GlaxoSmithKline) during a research involving many drugs of the antihistamine group. Cyclizine was quickly clinically found as a potent and long-acting antiemetic. Company named the substance – or more precisely cyclizine's hydrochloride form which it usually appears in – "marezine hydrochloride" and started to sell it in the United States under trade name Marezine. Selling was begun in France under trade name Marzine in 1965.
The substance received more credit when NASA chose it as a space antiemetic for the first occupied moon flight. Cyclizine was introduced to many countries as a common antiemetic. It is an over-the-counter drug in many countries because it has been well tolerated, although it has not been very much studied.
Recreational use 
Some people using methadone recreationally combine cyclizine with their methadone dose, a combination that is known to produce strong psychoactive effects. It has also been used recreationally by teenagers for its anticholinergic effects to induce hallucinations.
See also 
- "Valoid Tablets by Amdipharm". Electronic Medicines Compendium. Datapharm.
- "Diconal Tablets by Amdipharm". Electronic Medicines Compendium. Datapharm.
- "Bonine for Kids". Insight Pharmaceuticals.
- Sneader, Walter (2005). Drug discovery: a history. John Wiley & Sons. p. 404. ISBN 0-471-89979-8.
- Sittig, Marshall (1988). Pharmaceutical manufacturing encyclopedia. William Andrew. p. 406. ISBN 0-8155-1144-2.
- Ruben, S. M.; McLean, P. C.; Melville, J. (1989). "Cyclizine abuse among a group of opiate dependents receiving methadone". British Journal of Addiction 84 (8): 929–934. doi:10.1111/j.1360-0443.1989.tb00766.x. PMID 2775912.
- Bassett, K.; Schunk, J. E.; Crouch, B. I. (1996). "Cyclizine abuse by teenagers in Utah". The American Journal of Emergency Medicine 14 (5): 472–474. doi:10.1016/S0735-6757(96)90156-4. PMID 8765114.