Chemically, Antivert® (meclizine HCl) is 1-( p -chloro-(alpha)-phenylbenzyl) -4- ( -methylbenzyl) piperazine dihydrochloride monohydrate.


Inert ingredients for the tablets are: dibasic calcium phosphate; magnesium stearate; polyethylene glycol; starch; sucrose. The 12.5 mg tablets also contain: Blue 1. The 25 mg tablets also contain: Yellow 6 Lake; Yellow 10 Lake. The 50 mg tablets also contain: Blue 1 Lake; Yellow 10 Lake.


Antivert is an antihistamine which shows marked protective activity against nebulized histamine and lethal doses of intravenously injected histamine in guinea pigs. It has a marked effect in blocking the vasodepressor response to histamine, but only a slight blocking action against acetylcholine. Its activity is relatively weak in inhibiting the spasmogenic action of histamine on isolated guinea pig ileum.


Based on a review of this drug by the National Academy of Sciences-National Research Council and/or other information, FDA has classified the indications as follows:

Effective: Management of nausea and vomiting, and dizziness associated with motion sickness.

Possibly Effective: Management of vertigo associated with diseases affecting the vestibular system.

Final classification of the less than effective indications requires further investigation.


Meclizine HCl is contraindicated in individuals who have shown a previous hypersensitivity to it.

Since drowsiness may, on occasion, occur with use of this drug, patients should be warned of this possibility and cautioned against driving a car or operating dangerous machinery.

Patients should avoid alcoholic beverages while taking this drug. Due to its potential anticholinergic action, this drug should be used with caution in patients with asthma, glaucoma, or enlargement of the prostate gland.


Clinical studies establishing safety and effectiveness in children have not been done; therefore, usage is not recommended in children under 12 years of age.


Pregnancy Category B. Reproduction studies in rats have shown cleft palates at 25-50 times the human dose. Epidemiological studies in pregnant women, however, do not indicate that meclizine increases the risk of abnormalities when administered during pregnancy. Despite the animal findings, it would appear that the possibility of fetal harm is remote. Nevertheless, meclizine, or any other medication, should be used during pregnancy only if clearly necessary.


Drowsiness, dry mouth and, on rare occasions, blurred vision have been reported.



For the control of vertigo associated with diseases affecting the vestibular system, the recommended dose is 25 to 100 mg daily, in divided dosage, depending upon clinical response.

Motion Sickness:

The initial dose of 25 to 50 mg of Antivert should be taken one hour prior to embarkation for protection against motion sickness. Thereafter, the dose may be repeated every 24 hours for the duration of the journey.


Antivert®--12.5 mg tablets:

Bottles of 100 (NDC 0662-2100-66), (NDC 0049-2100-66)

Bottles of 1000 (NDC 0662-2100-82), (NDC 0049-2100-82)

Antivert®/25--25 mg tablets:

Bottles of 100 (NDC 0662-2110-66), (NDC 0049-2110-66)

Bottles of 1000 (NDC 0662-2110-82), (NDC 0049-2110-82)

Antivert®/50--50 mg tablets:

Bottles of 100 (NDC 0662-2140-66), (NDC 0049-2140-66)

Revised June 1996                                            69-2148-00-8