Lunarzin

• Approved Indications:
• Prophylaxis of migraine headaches in adults.
• Management of vertigo and balance disorders (including Ménière's disease and vestibular vertigo).
• Adjunctive treatment in certain forms of epilepsy, especially absence seizures and myoclonic seizures.
• Off-label/Clinically Accepted Uses:
• Prevention of cerebral ischemia symptoms.
• Treatment of movement disorders such as tardive dyskinesia (off-label in some countries).
• Management of vestibular migraines and other chronic migraine variants.
• Sometimes used in patients with chronic dizziness or motion sickness.

• Adults:
• Typical dose: 5 to 10 mg orally once daily, preferably in the evening.
• Dose for migraine prophylaxis often starts at 5 mg/day; may be increased to 10 mg/day if tolerated.
• Duration: Usually continued for 3 months or longer based on clinical response.
• Elderly:
• Start at lower dose (5 mg/day) with cautious titration due to increased susceptibility to side effects such as sedation and extrapyramidal symptoms.
• Pediatrics:
• Safety and efficacy not well established; use is generally not recommended or requires specialist supervision.
• Special Populations:
• No specific dose adjustment is recommended for mild to moderate hepatic or renal impairment.
• Use with caution in severe hepatic impairment.
• Administration Route:
• Oral tablets, taken preferably with food to reduce gastrointestinal discomfort.

Flunarizine is a selective calcium channel blocker with antihistaminic and sedative properties. It inhibits the influx of calcium ions through voltage-gated calcium channels in vascular smooth muscle and neurons, leading to vasodilation of cerebral blood vessels and reduction of neuronal excitability. By modulating calcium influx, flunarizine decreases neuronal hyperexcitability and stabilizes vascular tone, which helps prevent migraine attacks and reduces vertigo symptoms. It also exerts weak antagonistic effects on dopamine D2 receptors, which may contribute to some neurological side effects.

• Absorption:
  Well absorbed orally; peak plasma concentrations achieved within 4-6 hours.
• Bioavailability:
  Approximately 20-30% due to extensive first-pass metabolism.
• Distribution:
  Highly lipophilic; widely distributed in body tissues including the brain.
• Metabolism:
  Extensive hepatic metabolism mainly by cytochrome P450 enzymes (CYP2D6).
• Active Metabolites:
  No significant active metabolites reported.
• Elimination:
  Primarily excreted in feces via biliary secretion.
• Half-life:
  Long elimination half-life ranging between 18 to 20 hours, supporting once-daily dosing.

• Pregnancy:
  Classified as FDA Pregnancy Category C. Animal studies have shown adverse effects on fetal development; use only if potential benefits justify the risks.
• Lactation:
  Unknown if excreted in human milk. Caution advised; breastfeeding is generally not recommended during treatment.

• Primary Class: Calcium channel blocker
• Subclass: Non-dihydropyridine calcium channel antagonist with antihistaminic properties
• Additional: Migraine prophylactic agent, vestibular suppressant

• Known hypersensitivity to flunarizine or any formulation components.
• Patients with active or history of depression or suicidal ideation (due to risk of mood worsening).
• Parkinson’s disease or extrapyramidal disorders (due to dopamine antagonism).
• Severe hepatic impairment.
• Children under 18 years (due to lack of safety data).

• Risk of depression and suicidal ideation: Patients should be monitored for mood changes; discontinue if severe depression occurs.
• Extrapyramidal symptoms (e.g., parkinsonism, dystonia) may develop, especially with prolonged use or higher doses.
• Use caution in elderly patients due to increased sensitivity to sedation and movement disorders.
• Caution advised in patients with epilepsy as it may worsen seizure control in some cases.
• Avoid abrupt discontinuation to prevent rebound symptoms.
• Monitor liver function during prolonged treatment.

• Common:
• Sedation, drowsiness, fatigue.
• Weight gain.
• Dry mouth.
• Gastrointestinal discomfort (nausea, constipation).
• Neurological:
• Extrapyramidal symptoms: tremors, rigidity, bradykinesia.
• Dizziness, headache.
• Depression, mood changes.
• Rare/Serious:
• Suicidal ideation or behavior.
• Parkinsonism or other movement disorders.
• Allergic reactions including rash.

• CNS depressants: Enhanced sedative effects when combined with alcohol, benzodiazepines, or opioids.
• Antiparkinson drugs: May have antagonistic effects, worsening Parkinsonian symptoms.
• CYP2D6 inhibitors or inducers: May alter flunarizine metabolism affecting plasma levels.
• Other calcium channel blockers: Potential additive effects on vascular tone and CNS depression.
• Antidepressants: Use cautiously due to overlapping side effects like sedation and mood changes.

• Recent migraine management guidelines recommend flunarizine as a second-line prophylactic agent due to its efficacy balanced against tolerability concerns.
• Increased awareness and caution about neuropsychiatric adverse effects, especially depression, have led to stricter monitoring recommendations.
• No major changes in dosing but emphasis on individualized treatment duration based on patient response and side effect profile.

• Store at 20°C to 25°C (68°F to 77°F).
• Protect from moisture and light.
• Keep in tightly closed containers.
• Keep out of reach of children.
• No special refrigeration required.