Mirapex Drug Class and Perioperative Management for Hip Surgery
Mirapex (pramipexole) is a non-ergoline dopamine agonist that does not need to be discontinued before hip surgery, as there are no specific perioperative guidelines requiring its cessation for orthopedic procedures. 1, 2
Drug Classification
Pramipexole is classified as a non-ergoline aminobenzothiazole dopamine agonist with selective activity at D2-like dopamine receptor subfamilies (D2, D3, D4 subtypes), demonstrating preferential affinity for the D3 receptor subtype. 2, 3 The medication is FDA-approved for treating Parkinson's disease and moderate-to-severe restless leg syndrome. 1, 4
Perioperative Management Decision
Continue pramipexole through the perioperative period without interruption. 1 Unlike antiplatelet agents (clopidogrel, ticagrelor) or anticoagulants that require specific timing adjustments before hip surgery 5, dopamine agonists are not mentioned in any orthopedic perioperative guidelines as requiring discontinuation. 5
Key Rationale for Continuation:
No bleeding risk: Pramipexole does not affect coagulation pathways or platelet function, unlike medications that must be held before hip surgery. 1, 2
Withdrawal complications: Abrupt discontinuation of dopamine agonists in Parkinson's disease patients can precipitate severe motor deterioration, confusion, and neuroleptic malignant syndrome-like reactions. 1, 6
Anesthetic compatibility: The 2012 Association of Anaesthetists guidelines for proximal femoral fractures do not list dopamine agonists among medications requiring perioperative adjustment. 5
Critical Perioperative Considerations
Symptomatic Hypotension Risk
Monitor closely for orthostatic hypotension during dose escalation and the immediate postoperative period. 1 Dopamine agonists impair systemic blood pressure regulation, particularly during position changes common in hip surgery recovery. 1 However, this risk does not warrant discontinuation—rather, it requires vigilant blood pressure monitoring and careful patient positioning. 5
Somnolence and Fall Risk
Assess for excessive daytime sleepiness preoperatively, as pramipexole causes somnolence that may compound postoperative delirium risk. 1, 6 Patients treated with pramipexole have reported falling asleep during activities of daily living, with some events occurring up to one year after treatment initiation. 1 This is particularly relevant given that hip fracture patients already face elevated fall and confusion risks postoperatively. 5
Hallucinations in Elderly Patients
Age increases hallucination risk attributable to pramipexole—patients over 65 years have 5.2-6.8 times greater risk compared to placebo. 1 Given that hip fracture patients are predominantly elderly, anticipate and monitor for hallucinations postoperatively, which occurred in 9-16.5% of pramipexole-treated patients in clinical trials. 1
Dosing Considerations
Typical dosing ranges from 0.375 mg/day up to 4.5 mg/day in divided doses for Parkinson's disease, or 0.125-0.750 mg taken 2-3 hours before bedtime for restless leg syndrome. 4, 6 Do not adjust the established dose perioperatively unless adverse effects emerge. 1
Common Pitfalls to Avoid
Never discontinue pramipexole abruptly without neurologic consultation, as this risks severe motor decompensation in Parkinson's patients. 1, 6
Do not confuse pramipexole with antiplatelet agents that require specific washout periods (5-7 days for clopidogrel/ticagrelor/prasugrel) before hip surgery. 5
Avoid attributing all postoperative confusion to delirium alone—consider pramipexole-induced hallucinations, especially in patients over 65 years. 1
Do not overlook concomitant medications that increase pramipexole plasma levels (particularly cimetidine), which may exacerbate somnolence and hypotension perioperatively. 1