VASTEN 75

Indications

• Vertigo
• Tinnitus
• Nausea
• Vomiting
• Ménière's disease
• Motion sickness

Dosage

Children: For children aged 5-11 years, the recommended dose is 15 mg taken three times a day. For those aged 12-17 years, the dosage increases to 30 mg three times a day.

Adults: For adults, the typical dosage for the relief of symptoms of vestibular disorders is 30 mg taken three times a day. For motion sickness, 1 tablet (15 mg) should be taken three times a day, ideally starting 1-2 hours before travel.

Mechanism of action

Cinnarizine inhibits contractions of vascular smooth muscle cells by blocking L-type and T-type voltage gated calcium channels. Additionally, it binds to dopamine D2 receptors, histamine H1 receptors, and muscarinic acetylcholine receptors, contributing to its anti-emetic properties.

Pharmacodynamics

Cinnarizine functions as both an antihistamine and a calcium channel blocker. It acts as a competitive antagonist at histamine H1 receptors, which mediate various physiological activities including smooth muscle contraction and vasodilation. By blocking muscarinic acetylcholine receptors, it also exhibits anti-emetic effects. Its calcium channel blocking capability inhibits stimulation of the vestibular system, reducing symptoms of motion sickness.

Pharmacokinetics

Cinnarizine is well absorbed following oral administration, with peak plasma concentrations typically occurring within 1-3 hours. The drug is extensively metabolized in the liver, and its metabolites are primarily excreted via the kidneys. The half-life of cinnarizine is approximately 4-6 hours, although this may vary based on individual patient factors.

Contra-indications

• Acute porphyrias
• Epilepsy
• Glaucoma (in children)
• Parkinson's disease (in adults)
• Prostatic hypertrophy (in adults)
• Pyloroduodenal obstruction
• Susceptibility to angle-closure glaucoma (in adults)
• Urinary retention

Adverse effects

• Drowsiness
• Dry mouth
• Gastrointestinal disturbances
• Weight gain
• Extrapyramidal symptoms

Interactions

• Sedating antihistamines
• Other CNS depressants

Precautions

• Use with caution in patients with epilepsy
• Use with caution in patients with glaucoma
• Use with caution in patients with prostatic hypertrophy
• Use with caution in patients with Parkinson's disease

Pregnancy

Antihistamines, including Cinnarizine, should be used with caution during pregnancy, particularly in the third trimester, due to potential risks.

Breast-feeding

Cinnarizine is excreted in breast milk; caution is advised when used during breastfeeding.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Formulations

• Cinnarizine 15 mg tablets
• Cinnarizine oral suspension

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.

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.