Indication
It is indicated for the prophylaxis and treatment of nausea & vomiting during pregnancy & after surgery and nausea & vomiting induced by irradiation and motion sickness. It is also indicated for vertigo associated with vestibular system diseases. It is not indicated for using in children.
Pharmacology
Meclizine Hydrochloride prevents nausea and vomiting by reducing the activity of the center in the brain that controls nausea. It also prevents motion sickness by reducing excitability of neurons in the vestibular region of the brain. Pyridoxine Hydrochloride (vit. B6), either alone or combination has been used to prevent nausea and vomiting due to its antiemetic properties.
Dosage
Nausea and vomiting during pregnancy: 1 tablet 1-2 times daily (after taking food) or as directed by the physician. Nausea and vomiting after surgery: 1-2 tablets daily.Nausea and vomiting induced by irradiation: 1 tablet (shortly before or after the irradiation). Motion sickness: 1-2 tablets one hour prior to journey. This dose may be repeated every 24 hours, if required.Vertigo associated with vestibular system diseases: 1 tablet 2 times daily or as required.
Interaction
Isoniazid, cycloserine, penicillamine: reduces the effect of pyridoxine. Oral contraceptives: may decrease the plasma levels of pyridoxine. Alcohol, hypnotics, sedatives or anxiolytics: may increase the action of these drugs.Levodopa: pyridoxine reduces the effects of levodopa. Nitrofurantoin: pyridoxine accelerates the renal excretion of nitrofurantoin. So, dosage adjustment of nitrofurantoin may be necessary.Phenytoin: serum levels of phenytoin may be reduced.
Contradiction
It is contraindicated in patient with known hypersensitivity to this combination.
Side Effect
The side effects associated with the use of this combination be particularly caused by meclizine. There are allergies, blurred vision, dry mouth and fatigue.
Pregnancy
There is no evidence of adverse effects of this combination on pregnancy or on the health of the fetus or neonate. But account should be taken with the use of antihistamines to just before the parturition. Pyridoxine is considered as safe in pregnancy. Pyridoxine is excreted in human milk but meclizine is unknown whether it is excreted or not. So, this combination may be indicated during lactation, if clearly needed.
Precaution
Due to its anticholinergic action, this drug should be used with caution in patients with epilepsy, hyperthyroidism, severe heart failure, hypertension, glaucoma, prostatic hypertrophy, pyloric stenosis and bronchial asthma.
Overdose
Storage
Keep in a dry place away from light and heat. Keep out of the reach of children.