Sifrol Pramipexole Dihydrochloride Sustained release Tablets

1. Indications and Usage
Parkinson’s Disease:
Indicated for the treatment of the signs and symptoms of idiopathic Parkinson’s disease in adults. It is used as monotherapy or in combination with levodopa.
Restless Legs Syndrome (RLS):
Indicated for the treatment of moderate-to-severe primary Restless Legs Syndrome in adults.
2. Dosage and Administration
Recommended Dosage:
Parkinson’s Disease:
Initial: 0.375 mg once daily.
Titration: Increase by 0.375 mg/day every 5–7 days.
Maintenance: 1.5 mg to 4.5 mg once daily.
Restless Legs Syndrome:
Initial: 0.125 mg once daily.
Titration: Increase by 0.125 mg/day every 4–7 days.
Maintenance: Maximum dose 0.75 mg once daily.
Administration Instructions:
Take orally once daily with or without food.
Intact Swallowing: Swallow tablets whole with water. Do not chew, crush, or split the tablets, as this would destroy the sustained-release properties.
Discontinuation: Reduce the dose gradually (e.g., decrease by 1.5 mg/day per week) to avoid Neuroleptic Malignant Syndrome (NMS).
3. Mechanism of Action
Dopamine Agonist:
Pramipexole is a non-ergot dopamine agonist with high specificity for the D2 subfamily of dopamine receptors (specifically D3 > D2 > D4).
Physiological Effect:
It mimics the action of dopamine in the brain to compensate for the loss of dopaminergic neurons in the substantia nigra, thereby reducing motor symptoms (tremor, rigidity, bradykinesia) in Parkinson’s disease.
4. Safety and Warnings
Impulse Control Disorders:
Patients may experience pathological gambling, increased libido, hypersexuality, or compulsive spending/buying.
Somnolence and Sudden Sleep Onset:
Patients may experience excessive daytime sleepiness or sudden onset of sleep without warning. Caution is advised when driving or operating machinery.
Orthostatic Hypotension:
May cause hypotension and syncope, especially when starting treatment or increasing the dose.
Hallucinations:
May cause hallucinations, particularly in elderly patients or when used in combination with levodopa.
5. Adverse Reactions
Most Common:
Nausea, somnolence, dizziness, insomnia, constipation, fatigue, headache, and hallucinations. (RLS patients also report dizziness and somnolence).
6. Drug Interactions
Renal Excretion Competitors:
Cimetidine and ranitidine may decrease renal clearance of pramipexole by inhibiting active tubular secretion. Dose reduction of pramipexole may be required.
Antipsychotics:
Concomitant use with dopamine antagonists (e.g., haloperidol, risperidone) should be avoided as they may antagonize the therapeutic effect of pramipexole.
7. Pharmaceutical Information
Storage:
Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F). Protect from light and moisture.