Ropinirole is a non-ergoline dopamine agonist that selectively stimulates D2, D3, and D4 dopamine receptors in the brain. It is a cornerstone therapy for Parkinson's disease (PD) and Restless Legs Syndrome (RLS) in the Indian market, valued for its efficacy in managing motor symptoms and its potential to delay the need for levodopa therapy. It helps correct the dopamine deficiency characteristic of PD.
Adult: Parkinson's Disease: Start at 0.25 mg TID. Titrate weekly by 0.25 mg TID to target dose of 1 mg TID (3 mg/day). Max: 24 mg/day. RLS: Start at 0.25 mg once daily, 1-3 hours before bedtime. Titrate to 0.5 mg, then 1 mg, then 2 mg as needed, with at least 2 days between increments. Max: 4 mg/day.
Note: Take with or without food. Taking with food may reduce nausea. For RLS, take 1-3 hours before bedtime. Do not crush or chew extended-release tablets (if applicable to other strengths). For the 1mg immediate-release tablet, swallow whole with water. Do not abruptly discontinue.
Ropinirole mimics the action of dopamine by directly stimulating postsynaptic dopamine receptors (primarily D2 subfamily) in the striatum and substantia nigra. This stimulation compensates for the depleted endogenous dopamine in Parkinson's disease, leading to improved motor control. In RLS, its mechanism is believed to involve modulation of dopaminergic pathways in the spinal cord.
Pregnancy: Category C. Animal studies showed adverse effects. No adequate human studies. Use only if potential benefit justifies potential fetal risk. Registry data does not indicate major malformations.
Driving: Warn patients about potential for somnolence, sudden sleep attacks, dizziness, and syncope. Advise not to drive or operate machinery until they know how the drug affects them, especially during dose escalation.
| Fluvoxamine (and other potent CYP1A2 inhibitors) | Markedly increases ropinirole AUC (up to 12-fold). Contraindicated in RLS. In PD, reduce ropinirole dose if co-administered. | Major |
| Ciprofloxacin (moderate CYP1A2 inhibitor) | Increases ropinirole AUC (~80%). Monitor and consider dose reduction. | Moderate |
| Estrogens (e.g., Hormone Replacement Therapy) | May decrease ropinirole clearance by ~35%. Monitor for increased side effects. | Moderate |
| Other CNS Depressants (Alcohol, Benzodiazepines, Opioids) | Additive sedative effects. Increased risk of somnolence and sudden sleep onset. | Moderate |
| Dopamine Antagonists (e.g., Metoclopramide, Phenothiazines, Butyrophenones) | May diminish efficacy of ropinirole. Avoid concomitant use. | Moderate |
| Levodopa | Enhances therapeutic effect but may increase incidence of dyskinesias, hallucinations, and orthostasis. Levodopa dose may need reduction. | Moderate |