Nomosic

Approved Indications:

• Motion Sickness: For the prevention and treatment of nausea, vomiting, and dizziness associated with motion sickness.
• Vertigo: Used for the control of vertigo associated with vestibular system disorders, including:
• Ménière’s disease
• Labyrinthitis
• Vestibular neuronitis
• Postoperative Nausea and Dizziness: Occasionally used as adjunctive therapy to reduce dizziness following surgical procedures.

Clinically Accepted (Off-label) Uses:

• Pregnancy-induced Nausea and Vomiting (NVP): Occasionally used off-label for managing mild to moderate nausea in pregnancy under physician supervision.
• Radiation-induced Nausea: Sometimes used to relieve dizziness or nausea due to vestibular exposure to radiation.

Route of Administration: Oral

Adults:

• Motion Sickness: 25–50 mg orally, once daily, taken 1 hour before travel. May be repeated every 24 hours as needed.
• Vertigo: 25–100 mg daily, given as a single dose or divided into two doses depending on severity.

Pediatric Patients (≥12 years):

• Motion Sickness: 25–50 mg orally once daily. Do not exceed 50 mg in 24 hours.

Elderly:

• Start at the lower end of the dosage range (12.5–25 mg) to minimize risk of sedation or confusion. Monitor closely.

Renal Impairment:

• No specific dosage adjustment is recommended, but use with caution due to limited data.

Hepatic Impairment:

• Use cautiously; dosage adjustment may be necessary as the drug is metabolized hepatically.

Duration of Use:

• Motion Sickness: Use as needed before and during exposure.
• Vertigo: May be used for short- to medium-term symptom control based on clinical evaluation.

Meclizine Hydrochloride is a first-generation antihistamine that acts as a selective antagonist of central and peripheral histamine H1 receptors. It also exhibits anticholinergic and CNS depressant properties, which contribute to its antiemetic and antivertigo effects. By inhibiting histamine-mediated stimulation of the vestibular system and suppressing vestibular sensory input to the vomiting center in the medulla, Meclizine reduces nausea, vomiting, and dizziness associated with motion sickness and vertigo.

• Absorption: Rapidly absorbed after oral administration.
• Onset of Action: Typically within 1 hour.
• Bioavailability: Moderate; absorption may be affected by food.
• Peak Plasma Concentration: Reached within 3 hours.
• Distribution: Widely distributed; crosses the blood-brain barrier.
• Metabolism: Primarily hepatic via the CYP2D6 enzyme system.
• Elimination Half-life: Approximately 6 to 12 hours.
• Excretion: Mainly through the urine as metabolites.

• Pregnancy Category: Category B (US FDA) – Animal studies show no fetal harm, but adequate human studies are lacking. Commonly used for NVP under medical supervision.
• Lactation: It is unknown whether Meclizine is excreted into breast milk. Caution is advised; monitor the breastfed infant for sedation or irritability.
• Recommendation: Use during pregnancy and lactation only if clearly needed and under professional supervision.

• Primary Class: Antiemetic and Antivertigo Agent
• Subclass: First-generation Histamine H1 Receptor Antagonist (antihistamine)

• Known hypersensitivity to Meclizine or any excipients in the formulation
• Severe hepatic impairment
• Children under 12 years (for some formulations)
• Glaucoma (narrow-angle), due to risk of increased intraocular pressure
• Urinary retention or prostatic hypertrophy

• CNS Depression: May cause drowsiness and impair physical/mental ability; patients should avoid driving or operating machinery.
• Elderly Patients: Increased risk of confusion, sedation, and falls.
• Use in Glaucoma and BPH: May worsen conditions due to anticholinergic effects.
• Seizure Disorders: May lower seizure threshold; caution advised.
• Alcohol Use: Avoid concurrent use; enhances CNS depressant effects.
• Monitoring: Observe for signs of CNS toxicity, especially in high-risk or elderly patients.

Common Side Effects:

• Neurological: Drowsiness, dizziness, headache
• Gastrointestinal: Dry mouth, nausea, constipation
• Ophthalmic: Blurred vision
• General: Fatigue, coordination problems

Rare but Serious Side Effects:

• Hypersensitivity reactions (rash, itching, anaphylaxis – rare)
• Confusion or hallucinations (especially in elderly)
• Palpitations or tachycardia
• Urinary retention

Timing & Severity:

• Onset usually occurs within 1–2 hours post-dose
• Effects are generally mild and dose-dependent

• CNS Depressants (e.g., benzodiazepines, opioids, alcohol): Additive sedative effects; avoid or monitor closely.
• Anticholinergics (e.g., atropine, scopolamine): Additive adverse effects like dry mouth, blurred vision, urinary retention.
• CYP2D6 Inhibitors (e.g., fluoxetine, quinidine): May increase plasma levels of Meclizine, enhancing effects and side effects.
• Alcohol: Potentiates drowsiness and CNS depression; avoid use.

• Clinical Use in Pregnancy: Recent clinical guidelines allow Meclizine as an option for managing nausea in pregnancy (short-term use) under medical supervision.
• Otolaryngology Practice Guidelines: Meclizine remains a recommended first-line treatment for acute vestibular vertigo; long-term use discouraged due to sedation risk.
• Formulation Updates: Available in standard tablets, chewable tablets, and orally disintegrating tablets (ODT) to facilitate use in travel and acute settings.

• Temperature: Store at 20°C to 25°C (68°F to 77°F)
• Humidity: Keep in a dry place; protect from excess moisture
• Light: Store in the original container, protected from light
• Handling Instructions:
• Do not freeze
• Keep tightly closed
• Chewable or ODT forms should be used immediately once opened from the blister pack