Introduction
First synthesized by Janssen Pharmaceuticals in 1955, cinnarizine is an anti-histaminic drug mainly used for the control of vestibular disorders and motion sickness. Cinnarizine is a specific calcium channel blocker that primarily works on the central vestibular system to interfere with the signal transmission between vestibular apparatus of the inner ear and the vomiting centre of the hypothalamus. Cinnarizine could be also viewed as a nootropic drug because of its vasorelaxating abilities (due to calcium channel blockage), which happen mostly in brain. Combination use of cinnarizine with other nootropics, such as piracetam resulted in enhanced effect of boosting brain oxygen supply.
Uses
Cinnarizine is a drug used for the management of labyrinthine disorder symptoms, including vertigo, tinnitus, nystagmus, nausea, and vomiting.
For the treatment of vertigo/meniere's disease, nausea and vomiting, motion sickness and also useful for vestibular symptoms of other origins.
Associated Conditions
Pharmacodynamics
Cinnarizine is an antihistamine and a calcium channel blocker. Histamines mediate a number of activities such as contraction of smooth muscle of the airways and gastrointestinal tract, vasodilatation, cardiac stimulation, secretion of gastric acid, promotion of interleukin release and chemotaxis of eosinophils and mast cells. Competitive antagonists at histamine H1 receptors may be divided into first (sedating) and second (non-sedating) generation agents. Some, such as Cinnarizine also block muscarinic acetylcholine receptors and are used as anti-emetic agents. Cinnarizine through its calcium channel blocking ability also inhibits stimulation of the vestibular system.
Mechanism of Action
Cinnarizine inhibits contractions of vascular smooth muscle cells by blocking L-type and T-type voltage gated calcium channels. Cinnarizine has also been implicated in binding to dopamine D2 receptors, histamine H1 receptors, and muscarinic acetylcholine receptors.
Dosage
Children (5 to 12 years): Half of the adult dose.
Motion sickness: A dose of 30 mg two hours before the start of the journey and 15 mg every 8 hours during the journey.
Peripheral arterial diseases: 75 mg two or three times daily.
