Usage
Buclizine is an antihistamine primarily prescribed for the prevention and treatment of nausea, vomiting, and dizziness associated with motion sickness. It is also used to manage vertigo and can be used, though less commonly, for allergic conditions. Its pharmacological classification is antihistamine (piperazine derivative) with antiemetic properties. Buclizine acts by blocking histamine H1 receptors and muscarinic acetylcholine receptors in the brain, thereby reducing the stimulation of the vomiting center and vestibular pathways.
Alternate Names
International and regional variations exist but are not extensively documented. Brand names include Longifene, ApoBuclizine, and Vibazine. Note this might not be an exhaustive list.
How It Works
Pharmacodynamics: Buclizine exerts its effects through the antagonism of central H1 and muscarinic receptors. This dual action mitigates vestibular stimulation responsible for motion sickness and vertigo symptoms.
Pharmacokinetics: Buclizine is well-absorbed orally. Its metabolism is primarily hepatic, and it is likely metabolized by cytochrome P450 enzymes, although the specific enzymes are not clearly identified in the literature. Elimination pathways are not definitively described but presumably involve both renal and hepatic excretion.
Mode of Action: The drug’s antiemetic effect stems from its central antihistaminic activity on the vomiting center and the chemoreceptor trigger zone. The antivertigo effect is mediated through central antimuscarinic action, which inhibits vestibular stimulation.
Receptor Binding/Enzyme Inhibition/Neurotransmitter Modulation: Buclizine binds to H1 histamine receptors and muscarinic acetylcholine receptors. This binding competitively inhibits the actions of histamine and acetylcholine at these receptors, thereby mitigating their effects on nausea, vomiting, and balance. The details on specific CYP enzyme interactions are not well-elucidated in the literature.
Dosage
Standard Dosage
Adults:
- Motion Sickness: 25-50 mg orally, taken 30 minutes before travel. Doses can be repeated every 4-6 hours as needed, not exceeding 150mg daily.
- Vertigo: 25-100 mg orally, divided into smaller doses throughout the day.
Children:
- Dosing must be determined by a doctor. Dosage may be based on age and weight for children.
- For motion sickness, a dose of 1 mg/kg body weight intramuscularly, up to three times a day, has been mentioned in the literature.
Special Cases:
- Elderly Patients: Start with lower doses due to potential increased sensitivity to anticholinergic effects. Dosage adjustments should be based on individual patient responses.
- Patients with Renal Impairment: Use with caution. Dose adjustments may be necessary, based on the degree of impairment.
- Patients with Hepatic Dysfunction: Use with caution. Monitor closely for adverse effects.
- Patients with Comorbid Conditions: Caution advised in patients with glaucoma, prostatic hypertrophy, and gastrointestinal obstruction.
Clinical Use Cases
Buclizine is not typically recommended for use in the contexts of:
- Intubation
- Surgical Procedures
- Mechanical Ventilation
- Intensive Care Unit (ICU) Use
- Emergency Situations
Dosage Adjustments
Adjustments should be made based on individual patient responses and the severity of the condition being treated. Consideration should be given to renal and hepatic function.
Side Effects
Common Side Effects
- Drowsiness
- Dry mouth
- Blurred vision
Rare but Serious Side Effects
- Allergic reactions (difficulty breathing, swelling of face, lips, tongue or throat)
- Confusion
- Hallucinations
- Seizures
Long-Term Effects
Long-term effects are not well-documented but should be considered given the potential for anticholinergic complications with prolonged use.
Adverse Drug Reactions (ADR)
Significant ADRs mirror rare and serious side effects and warrant immediate medical attention.
Contraindications
- Hypersensitivity to buclizine
- Newborn infants
- Narrow-angle glaucoma
- Urinary retention
- Pyloric or duodenal obstruction
Drug Interactions
- Alcohol
- CNS depressants (e.g., sedatives, hypnotics)
- Anticholinergic drugs (e.g., atropine)
- MAO inhibitors
Pregnancy and Breastfeeding
While buclizine hasn’t shown definitive evidence of birth defects in human studies, animal studies suggest potential risks. Use during pregnancy only if potential benefit justifies the risk to the fetus. Its presence in breast milk and impact on nursing infants is unknown. Caution is advised.
Drug Profile Summary
- Mechanism of Action: H1 receptor and muscarinic acetylcholine receptor antagonist.
- Side Effects: Drowsiness, dry mouth, blurred vision (common); allergic reactions, seizures, hallucinations (rare but serious).
- Contraindications: Hypersensitivity, newborns, glaucoma, urinary retention, GI obstruction.
- Drug Interactions: Alcohol, CNS depressants, anticholinergics, MAO inhibitors.
- Pregnancy & Breastfeeding: Potential risk; use with caution.
- Dosage: Refer to detailed dosage guidelines.
- Monitoring Parameters: Observe for adverse effects, especially in elderly patients and those with hepatic/renal impairment.
Popular Combinations
Buclizine is not typically used in combination regimens.
Precautions
Standard precautions apply, including assessment of patient history for relevant contraindications and drug interactions. Caution in patients with hepatic/renal impairment and elderly patients is advised.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Buclizine?
A: Please refer to detailed dosage guidelines.
Q2: How does Buclizine work for motion sickness?
A: It inhibits the stimulation of the vomiting center and vestibular pathways by blocking H1 and muscarinic receptors.
Q3: What are the main side effects of Buclizine?
A: Common side effects include drowsiness, dry mouth, and blurred vision. Rare but serious side effects include allergic reactions, confusion, hallucinations, and seizures.
Q4: Can Buclizine be used during pregnancy?
A: Use with caution during pregnancy only if the benefits outweigh the potential risks to the fetus.
Q5: How should Buclizine be administered?
A: Buclizine is typically administered orally, usually as a tablet.
Q6: Does Buclizine interact with other medications?
A: Yes, it can interact with alcohol, CNS depressants, anticholinergic drugs, and MAO inhibitors.
Q7: What should patients be advised regarding Buclizine use?
A: Patients should be cautioned about potential drowsiness and advised to avoid driving or operating machinery if affected. They should also avoid alcohol while taking buclizine.
Q8: Is buclizine appropriate for children?
A: Yes, but the dosage must be determined by a doctor.
Q9: Is buclizine safe for patients with kidney or liver problems?
A: Use with caution in patients with renal or hepatic impairment, as dose adjustments may be necessary.
Q10: How long does it take for Buclizine to work?
A: For motion sickness, it is generally recommended to take buclizine 30 minutes before travel.
This information is current as of February 16, 2025, and is intended for use by qualified medical professionals in India. Please consult the latest prescribing information and relevant guidelines for the most up-to-date details.
