Schedule H

Oral

Formulation Strengths

Tablets 5 mg, 10 mg

INDICATIONS + DOSING — FOR CLINICIAN USE ONLY

Primary Indications (Approved / Standard in India)

1. Migraine Prophylaxis (Adults)

Parameter Recommendation

Starting dose 10 mg once daily at bedtime

Titration Assess response after 2 months; if no benefit, discontinue

Usual maintenance dose 10 mg once daily at bedtime

Maximum dose 10 mg/day

Duration If effective, continue for up to 6 months; then reassess need for continuation

Key notes Not for acute migraine treatment; taper gradually if discontinuing after prolonged use; elderly start at 5 mg/day

1. Vertigo due to Vestibular Disorders (Meniere's disease, vestibular neuritis, BPPV)

Parameter Recommendation

Starting dose 10 mg once daily at bedtime

Titration Not applicable

Usual maintenance dose 10 mg once daily

Maximum dose 10 mg/day

Duration Short-term use only (maximum 2 months); reassess if symptoms persist

Key notes Monitor for extrapyramidal symptoms especially with prolonged use; discontinue if EPS develops

Secondary Indications – Adults (Off-label, if any)

Indication Dose Duration Notes Evidence Basis

Refractory epilepsy (adjunctive therapy) — OFF-LABEL 10 mg once daily at bedtime Per specialist judgement Specialist only Small case series; Indian neurology practice

Alternating hemiplegia of childhood (adults with residual symptoms) — OFF-LABEL 5–10 mg once daily Long-term under specialist care Specialist only Limited case reports; European practice adopted in select Indian centres

PAEDIATRIC DOSING (Specialist Only)

⚠️ Not recommended below age 12 years except under paediatric neurologist supervision. Safety not established in children under 5 years.

Primary Indications (Approved / Standard in India)

1. Migraine Prophylaxis (Children ≥12 years)

12–17 years 0.15–0.2 mg/kg/day once daily at bedtime 5–10 mg once daily at bedtime 10 mg/day

Parameter Recommendation

Starting dose 5 mg once daily at bedtime

Titration May increase to 10 mg/day after 2 weeks if tolerated and needed

Usual maintenance dose 5–10 mg once daily

Maximum dose 10 mg/day

Duration Trial for 3 months; discontinue if no benefit

Monitoring Weight gain, sedation, extrapyramidal signs; reassess periodically

Secondary Indications – Paediatrics (Off-label, if any)

Indication Dose Duration Notes Evidence Basis

Benign paroxysmal vertigo of childhood — OFF-LABEL 5 mg once daily at bedtime Maximum 2 months without reassessment Specialist only (paediatric neurology/ENT) Indian paediatric ENT practice; limited published data

Alternating hemiplegia of childhood — OFF-LABEL 5–10 mg/day in single dose Long-term under specialist Specialist only European case series; adopted in select Indian paediatric neurology centres

⚠️ Avoid in infants and children under 5 years due to lack of safety data.

Mild to moderate impairment No dose adjustment required

Dialysis No specific data; use only if clearly indicated with close monitoring

• History of depressive illness or major depressive disorder

• History or presence of extrapyramidal symptoms

• Parkinson's disease or parkinsonism

• Known hypersensitivity to flunarizine or related compounds

• Severe hepatic dysfunction

• Porphyria

• Elderly patients — increased risk of parkinsonism, especially with chronic use

• History of bipolar disorder or suicidal ideation

• Long-term use (>6 months) — significantly increases risk of EPS and depression

• Obesity or predisposition to weight gain

• Sedation — may impair driving and activities requiring alertness

• Concurrent use of other CNS depressants

• Pre-existing bradycardia or conduction abnormalities

Aspect Recommendation

Overall safety Avoid if possible; not formally classified; insufficient human data

Animal data Inconclusive regarding teratogenicity

Preferred alternatives Propranolol (for migraine prophylaxis); amitriptyline (with obstetric supervision)

When it may be used Only if benefit clearly outweighs risk; specialist input required

Monitoring Fetal growth (USG), maternal sedation, fetal heart rate

Aspect Recommendation

Compatibility Use with caution; likely excreted in breastmilk

Expected levels in milk Unknown; likely low to moderate based on lipophilicity

Preferred alternatives Propranolol for migraine prophylaxis (better lactation safety data)

Recommendation Avoid if possible; consider temporary cessation of breastfeeding if prolonged use required

Infant monitoring Sedation, poor feeding, excessive sleepiness, weight gain patterns

Parameter Recommendation

Starting dose 5 mg once daily at bedtime

Titration Slow; increase only if well tolerated after 2–4 weeks

Maximum dose 10 mg/day (but 5 mg often sufficient)

Duration limit Avoid use beyond 6 months unless specialist oversight

Extra risks Sedation, confusion, parkinsonism, gait instability leading to falls, depression

Monitoring Neurological examination for EPS at each visit; mood assessment

Interacting Drug Effect Management

CNS depressants (benzodiazepines, opioids, sedative antihistamines) Additive sedation; increased risk of respiratory depression Avoid combination if possible; if unavoidable, use lowest doses and monitor closely

Alcohol Marked increase in sedation and CNS depression Completely avoid alcohol during treatment

Antipsychotics (haloperidol, risperidone, olanzapine) Additive risk of extrapyramidal symptoms Avoid combination; increased parkinsonism risk

Carbamazepine Induces CYP enzymes; reduces flunarizine levels May require higher flunarizine doses; monitor efficacy

Phenytoin CYP enzyme induction; decreased flunarizine effect Monitor for reduced efficacy; adjust dose if needed

Interacting Drug Effect Management

Beta-blockers (propranolol, metoprolol) Slight additive CNS depression; possible additive bradycardia Monitor for fatigue, bradycardia; often used together in migraine

Valproate Additive weight gain; possible enhanced CNS effects Monitor weight and sedation closely

Topiramate Additive CNS effects; but topiramate may offset weight gain Monitor for cognitive effects

Macrolide antibiotics (erythromycin, clarithromycin) Weak CYP3A4 inhibition; may increase flunarizine levels Monitor for increased sedation

Antidepressants (SSRIs, TCAs) Possible additive effects on mood; monitor for depression Use with caution; monitor mood closely

Levodopa May reduce efficacy of levodopa in Parkinson's patients Avoid flunarizine in Parkinson's disease

• Drowsiness and sedation (most common)

• Weight gain (significant; may be 2–5 kg over months)

• Increased appetite

• Fatigue and asthenia

• Dry mouth

• Gastrointestinal discomfort (nausea, dyspepsia)

• Insomnia (paradoxical, rare)

Adverse Effect Notes

Drug-induced parkinsonism Tremor, rigidity, bradykinesia — requires immediate discontinuation

Depression and suicidal ideation May occur even after weeks of therapy; discontinue and refer for psychiatric evaluation

Extrapyramidal symptoms (akathisia, dystonia, tardive dyskinesia) Discontinue immediately; may require anticholinergic treatment

Galactorrhea (rare) Due to dopamine antagonist-like effects; discontinue

Severe hepatotoxicity (very rare) Monitor LFTs if symptoms suggestive

⚠️ Any neuropsychiatric or movement disorder symptoms require immediate drug discontinuation.

Timing Parameters to Monitor

Baseline Mood status (PHQ-9 or clinical assessment); body weight; neurological examination for EPS; liver function if hepatic concerns

After initiation (2–4 weeks) Sedation level; mood changes; weight

Every 1–2 months EPS assessment; depressive symptoms; weight monitoring

At 2–3 months Assess efficacy; discontinue if no benefit

Long-term (if continued >6 months) Formal neurological review for EPS; mood assessment; consider drug holiday

Brand Name Manufacturer

Sibelium Johnson & Johnson

Flunarin Sun Pharma

Flurint Intas

Fluzac Unichem

Flunil Torrent

Migranex Micro Labs

Vertigon-F Wallace

Various generics Multiple manufacturers

• NLEM Status: Not included in NLEM 2022; price not NPPA-controlled

• Availability: Widely available across pharmacies

1. Delayed onset: Therapeutic benefit in migraine prophylaxis takes 4–8 weeks; counsel patients about patience with therapy before judging efficacy.

1. Depression screening: Always screen for history of depression before starting; this is an absolute contraindication often missed in practice.

1. Time-limited therapy: Plan for 6-month maximum duration initially; schedule "drug holidays" to reassess ongoing need and allow recovery from subclinical EPS.

1. Weight gain management: Warn patients proactively about weight gain; consider dietary counselling at initiation especially in obese patients.

1. Elderly prescribing: Use 5 mg dose only in patients >65 years; monitor for subtle parkinsonian features at every visit.

1. Not for acute migraine: Ensure patients understand this is preventive therapy only; provide separate rescue medication for acute attacks.

flunarizine; migraine-prophylaxis; vertigo; vestibular-disorders; calcium-channel-blocker; extrapyramidal-risk; depression-risk; weight-gain; elderly-caution; Schedule-H

RxIndia v1.0 — 02 May 2025

• CDSCO Approved Drug List

• Indian Pharmacopoeia (IP)

• National Formulary of India (NFI)

• API Textbook of Medicine, 11th Edition

• AIIMS Drug Formulary

• ICMR Neurology Division expert consensus

• Indian Association of Otorhinolaryngology (AOI) practice guidelines

• Indian neurology and ENT specialist practice protocols

• Goodman & Gilman's The Pharmacological Basis of Therapeutics