pramipexol

Pramipexole (also spelled pramipexol in some sources) is a non-ergoline dopamine agonist used in the treatment of Parkinson's disease (PD) and restless legs syndrome (RLS). It acts by stimulating dopamine D2 and D3 receptors, with higher affinity for D3 receptors, thereby mimicking the effects of dopamine in brain circuits impaired in PD and RLS.

In Parkinson's disease, pramipexole can be used as initial monotherapy in early disease and as an adjunct to levodopa in later stages to improve motor symptoms and reduce fluctuations. In restless legs syndrome, it relieves uncomfortable sensations and the urge to move, particularly in the evening or at night.

Pramipexole is available in immediate-release tablets and an extended-release formulation for once-daily dosing. The dose is typically titrated based on efficacy and tolerability; RLS regimens often start at 0.125 mg at bedtime, while PD regimens vary and may be increased to several milligrams per day. The drug is primarily cleared by the kidneys, with a half-life of about 8 to 12 hours; dose adjustments are recommended for renal impairment. Hepatic metabolism is minimal.

Common adverse effects include nausea, dizziness, somnolence, orthostatic hypotension, edema, and constipation. More serious but less frequent risks include hallucinations, impulse control disorders, and sudden sleep episodes. Pramipexole should be used with caution in patients with psychosis or severe renal impairment; interactions with other dopaminergic medications can enhance side effects.

Pramipexole was approved for PD in the late 1990s and later for RLS; it is marketed under various brand names depending on country. As with other dopamine agonists, monitoring for behavioral changes and sleepiness is advised, and the lowest effective dose should be used to minimize adverse effects.