Amlodipine Prior to Hip Replacement
Continue amlodipine through the day of surgery for hip replacement. 1, 2
Rationale for Continuation
Calcium channel blockers like amlodipine should be maintained perioperatively because they do not cause the severe intraoperative hypotension associated with ACE inhibitors or ARBs. 2 The ACC/AHA guidelines explicitly recommend continuing medical therapy for hypertension until surgery in patients undergoing planned elective major procedures. 1
Key Distinguishing Features of Amlodipine
No significant intraoperative hypotension risk: Unlike ACE inhibitors and ARBs, calcium channel blockers do not impair the vasopressor response during anesthesia and do not cause the "vasoplegia syndrome" seen with renin-angiotensin system blockers. 1
Long half-life provides stability: Amlodipine has a 40-60 hour elimination half-life with gradual onset and offset of action, preventing abrupt hemodynamic changes if a dose is missed. 3, 4
Smooth 24-hour blood pressure control: The drug maintains consistent antihypertensive effect throughout the dosing interval without significant fluctuation, which is advantageous in the perioperative period. 5
Specific Perioperative Management Algorithm
Preoperative Phase
Continue amlodipine on the morning of surgery with a sip of water. 1, 2
Verify blood pressure control: If BP is ≥180/110 mmHg despite amlodipine, consider deferring elective surgery until better control is achieved. 1
Do NOT substitute or discontinue: Unlike ACE inhibitors/ARBs which should be held 24 hours before surgery, calcium channel blockers are safe to continue. 2
Intraoperative Management
For perioperative hypertension (BP ≥160/90 mmHg or SBP elevation ≥20% of preoperative value persisting >15 minutes): Use IV agents such as clevidipine, esmolol, nicardipine, or nitroglycerin. 1
Clevidipine is particularly useful as it is also a dihydropyridine calcium channel blocker with ultra-short half-life, providing seamless transition from oral amlodipine. 1
Postoperative Management
Resume amlodipine as soon as oral intake is tolerated, typically on postoperative day 1. 1
Monitor for hypotension in the immediate postoperative period, particularly if the patient received IV antihypertensives intraoperatively. 1
Critical Pitfalls to Avoid
Do not confuse amlodipine management with ACE inhibitor/ARB management. The ACC/AHA guidelines specifically state that discontinuation of ACE inhibitors or ARBs perioperatively may be considered (Class IIb), but this does NOT apply to calcium channel blockers. 1, 2
Do not abruptly discontinue if patient is also on beta blockers. If the patient is taking both amlodipine and a beta blocker, both should be continued, as abrupt beta blocker withdrawal is potentially harmful. 1
Do not withhold amlodipine due to concerns about "all antihypertensives." The European guidelines note that calcium channel blockers, particularly diltiazem, may be considered as alternatives when beta blockers are contraindicated, and they should be continued in patients with Prinzmetal angina. 1
Special Considerations for Hip Replacement
VTE prophylaxis interaction: Hip arthroplasty requires thromboprophylaxis, but amlodipine does not interact with anticoagulants or increase bleeding risk. 1
No impact on bone healing: Unlike some medications, calcium channel blockers do not adversely affect fracture healing or bone metabolism. 4, 6
Renal protection: In patients with baseline renal dysfunction (common in elderly hip replacement candidates), amlodipine maintains efficacy without significant accumulation or worsening of renal function. 7
Evidence Quality Note
The recommendation to continue calcium channel blockers is based on Class IIa (reasonable to continue) evidence from ACC/AHA guidelines, with the specific guidance that they do not cause the problematic intraoperative hypotension seen with ACE inhibitors/ARBs. 1, 2 The European guidelines provide Class I recommendation for continuation in specific conditions (Prinzmetal angina) and do not recommend routine discontinuation. 1