Meclizine

Meclizine is a Histamine H₁ Antagonist belonging to Antiemetic agent.

Meclizine is a histamine H1 antagonist used to treat nausea, vomiting, and dizziness associated with motion sickness.

The time taken to reach peak plasma concentration is approximately 3.1 ± 1.4 hours. The Volume of distribution of meclizine is approximately 7 L/kg. Meclizine is excreted mainly via Urine and feces as unchanged drug and metabolites.

Meclizine shows common side effects like Vomiting, xerostomia, Anaphylaxis, Drowsiness, fatigue, headache, Blurred vision.

Meclizine is available in the form of Oral Tablet.

Meclizine is available in India, US, Canada, China, Philippines Japan, Malaysia, Singapore, France, and Italy.

Meclizine is an Antiemetic agent belonging to the class Histamine H₁ Antagonist.

The antagonistic action on the H1 receptors, meclizine primarily works by inhibiting signaling pathway transduction through histaminergic neurotransmission from the vestibular nuclei and NTS to the CTZ and medullary vomiting center. Meclizine may also decrease the labyrinth excitability and vestibular stimulation.

The Onset and Duration of action of Meclizine is approximately 1 hour and 24 hours respectively.

The time to reach peak plasma concentrations (Cmax) of meclizine is about 3 hours post-dose, with the value ranging from 1.5 to 6 hours.

Meclizine is available in the form of Oral tablet.

Meclizine tablet taken orally, usually in divided dose.

Meclizine is a histamine H1 antagonist with antiemetic and antivertigo properties. It is used in the symptomatic treatment of motion sickness and control of vertigo associated with vestibular system diseases. It also exhibits anticholinergic, central nervous system depressant, and local anesthetic effects.

Meclizine is a Histamine H₁ Antagonist belonging to Antiemetic agent.

Antihistamine suppresses vestibular end-organ receptors and inhibits activation of central cholinergic pathways.

Meclizine is approved for use in the following clinical indications

• Motion sickness
• Vertigo, acute episodes

• Motion sickness

Adult Oral Dose: 12.5 to 25 mg every 6 to 8 hours as needed; administer first dose 30 to 60 minutes prior to exposure.

Maximum dose: 100 mg/day.

Children ≥12 years and Adolescents: Oral: 25 to 50 mg 1 hour before travel, repeat dose every 24 hours, if needed.

• Vertigo, acute episodes

Adult Oral Dose: Initial: 12.5 to 25 mg every 6 to 12 hours as needed; may increase to 50 mg per dose as needed based on response and tolerability.

Maximum dose: 100 mg/day.

Children ≥12 years and Adolescents: Oral: 25 to 100 mg/day in 3 or 4 divided doses.

Meclizine is available in various strengths a 25 mg; 12.5 mg; 50 mg; 30 mg.

Meclizine is available in the form of Oral tablet.

Meclizine is contraindicated in patients with

• Meclizine is contraindicated in patients with a hypersensitivity to meclizine or any of the inactive ingredients.

• Drowsiness

Since drowsiness may occur with use of Meclizine, patients should be warned of this possibility and cautioned against driving a car or operating dangerous machinery. Patients should avoid alcoholic beverages while taking Meclizine.

• Concurrent Medical Conditions

Because of its potential anticholinergic action, Meclizine should be used with caution in patients with asthma, glaucoma, or enlargement of the prostate gland.

Avoid Consumption of alcohol alcohol may cause additive CNS depressant effects.

There are no data on the presence of meclizine in human milk, the effects on the breastfed infant, or the effects on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for Meclizine and any potential adverse effects on the breastfed infant from Meclizine or from the underlying maternal condition.

Pregnancy category B

Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women.

• Common

Drowsiness, Rarely, blurred vision, Dry mouth, vomiting, Fatigue, Anaphylactic reaction, Headache.

CNS Depressants

There may be increased CNS depression when Meclizine is administered concurrently with other CNS depressants, including alcohol [see Warnings and Precautions (5.1)].

CYP2D6 Inhibitors

Based on in-vitro evaluation, meclizine is metabolized by CYP2D6. Therefore, there is a possibility for a drug interaction between Meclizine and CYP2D6 inhibitors. Therefore, monitor for adverse reactions and clinical effect accordingly.

The common side effects of Meclizine include the following

• Common side effects

Vomiting, xerostomia, Anaphylaxis, Drowsiness, fatigue, headache, Blurred vision.

• Rare side effects

Urinary retention, Dizziness, memory impairment.

• Pregnancy

Pregnancy Category B

Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women.

• Nursing Mothers

There are no data on the presence of meclizine in human milk, the effects on the breastfed infant, or the effects on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for Meclizine and any potential adverse effects on the breastfed infant from Meclizine or from the underlying maternal condition.

• Pediatric Use

Safety and effectiveness in pediatric patients have not been established.

• Geriatric Use

In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

• Pharmacodynamic

Meclizine works on the higher centres of the brain to reduce nausea, vomiting, or vertigo. It is effective against nausea and vomiting arising from many causes, including motion sickness and disorders affecting the vestibular system.

• Pharmacokinetics

Absorption

Time taken to reach peak plasma concentration is approximately 3.1 ± 1.4 hours.

Distribution

Volume of distribution of meclizine is approximately 7 L/kg.

Metabolism and Excretion

Meclizine is excreted mainly via Urine and feces as unchanged drug and metabolites.

• https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/010721s063lbl.pdf
• https://www.drugs.com/meclizine.html
• https://go.drugbank.com/drugs/DB00737
• https://medlineplus.gov/druginfo/meds/a682548.html#:~:text=Meclizine is used to prevent,if taken before symptoms appear.
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• https://www.uptodate.com/contents/meclizine-drug-information?search=meclizine&source=panel_search_result&selectedTitle=1~24&usage_type=panel&kp_tab=drug_general&display_rank=1
• https://www.rxlist.com/antivert-drug.htm#clinpharm