MECLIZINE HYDROCHLORIDE

Meclizine hydrochloride, a histamine (H1) receptor antagonist, is a white to slightly yellowish, crystalline powder. It has the following structural formula: Chemically, meclizine hydrochloride, USP is 1-(p-chloro-α-phenylbenzyl)-4-(m-methylbenzyl) piperazine dihydrochloride monohydrate. Inactive ingredients for the tablets are: hypromellose, lactose monohydrate, magnesium stearate, microcrystalline cellulose, silicon dioxide and sodium starch glycolate. In addition, the 12.5 mg tablet contains FD&C Blue # 1 Aluminum Lake; and the 25 mg tablet contains D&C Yellow # 10 Aluminum Lake and FD&C Yellow # 6 Aluminum Lake. Each meclizine hydrochloride 12.5 mg tablet contains 12.5 mg of meclizine dihydrochloride equivalent to 10.53 mg of meclizine free base. Each meclizine hydrochloride 25 mg tablet contains 25 mg of meclizine dihydrochloride equivalent to 21.07 mg of meclizine free base. Image

Meclizine hydrochloride tablets are indicated for the treatment of vertigo associated with diseases affecting the vestibular system in adults. Meclizine hydrochloride tablets are indicated for the treatment of vertigo associated with diseases affecting the vestibular system in adults ( 1 ).

Recommended dosage: 25 mg to 100 mg daily, in divided doses ( 2.1 ). Tablets: Swallow whole ( 2.2 ). 2.1 Recommended Dosage The recommended dosage is 25 mg to 100 mg daily administered orally, in divided doses, depending upon clinical response. 2.2 Administration Instructions Meclizine hydrochloride tablets must be swallowed whole.

Meclizine hydrochloride tablets are contraindicated in patients with a hypersensitivity to meclizine or any of the inactive ingredients [see Adverse Reactions ( 6 ) and Description ( 11 )]. Meclizine hydrochloride tablets are contraindicated in patients with hypersensitivity to meclizine or any of the inactive ingredients ( 4 ).

The following adverse reactions associated with the use of meclizine hydrochloride were identified in clinical studies or postmarketing reports. Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Anaphylactic reaction, drowsiness, dry mouth, headache, fatigue, and vomiting. On rare occasions blurred vision has been reported. Common adverse reactions are anaphylactic reaction, drowsiness, dry mouth, headache, fatigue, and vomiting. On rare occasions blurred vision has been reported ( 6 ). To report SUSPECTED ADVERSE REACTIONS, contact Zydus Pharmaceuticals (USA) Inc. at 1-877-993-8779 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

Coadministration of meclizine hydrochloride with other CNS depressants, including alcohol, may result in increased CNS depression ( 7.1 ). CYP2D6 inhibitors: As meclizine is metabolized by CYP2D6, there is a potential for drug-drug interactions between meclizine hydrochloride and CYP2D6 inhibitors ( 7.2 ). 7.1 CNS Depressants There may be increased CNS depression when meclizine hydrochloride is administered concurrently with other CNS depressants, including alcohol [see Warnings and Precautions ( 5.1 )] . 7.2 CYP2D6 Inhibitors Based on in-vitro evaluation, meclizine is metabolized by CYP2D6. Therefore, there is a possibility for a drug interaction between meclizine hydrochloride and CYP2D6 inhibitors. Therefore, monitor for adverse reactions and clinical effect accordingly.