Stugeron Mechanism of Action

Pharmacotherapeutic group: antivertigo preparations. ATC code: N07CA02.
Pharmacology: Pharmacodynamics: Cinnarizine has an anti-histamine (H1)-effect. Cinnarizine inhibits contractions of vascular smooth muscle cells by blocking calcium channels. In addition to this direct calcium antagonism cinnarizine decreases the contractile activity of vasoactive substances, such as norepinephrine and serotonin, by blocking receptor-operated calcium channels. Blockade of the cellular influx of calcium is tissue-selective, and results in anti-vasoconstrictor properties without effect on blood pressure and heart rate.
Cinnarizine may further improve deficient microcirculation by increasing erythrocyte deformability and decreasing blood viscosity. Cellular resistance to hypoxia is increased. Cinnarizine inhibits stimulation of the vestibular system, which results in suppression of nystagmus and other autonomic disturbances. Acute episodes of vertigo can be prevented or reduced by cinnarizine.
Pharmacokinetics: Absorption: The peak plasma levels of cinnarizine are obtained 1 to 3 hours after intake.
Distribution: The plasma protein binding of cinnarizine is 91%.
Metabolism: Cinnarizine is extensively metabolized mainly via CYP2D6.
Elimination: The reported elimination half-life for cinnarizine ranges from 4 to 24 hours. The elimination of metabolites is about 1/3 in the urine and 2/3 in the feces.
Toxicology: Non-Clinical Information: A comprehensive battery of nonclinical safety studies showed that effects were observed only after chronic exposures that were 10 to 160 times (on a mg/kg basis) those at the maximum recommended human dose of 100 mg/day, calculated as 2 mg/kg as based on a 50 kg person.