Which cardiology medications are contraindicated in patients with an estimated glomerular filtration rate below 30 mL/min?

Cardiology Medications Contraindicated in eGFR <30 mL/min

The following cardiology medications are absolutely contraindicated or cannot be dosed safely when eGFR falls below 30 mL/min/1.73 m²: fondaparinux, dabigatran, rivaroxaban, edoxaban, exenatide, and metformin (though metformin is used for diabetes comorbidity, not primary cardiac indication). 1, 2

Absolute Contraindications

Anticoagulants

• Fondaparinux is absolutely contraindicated when CrCl <30 mL/min and should be avoided entirely 1
• Dabigatran cannot be dosed safely when CrCl <30 mL/min or in patients on dialysis—dosing recommendations cannot be provided per FDA labeling 2
• Rivaroxaban is contraindicated when CrCl <30 mL/min 1
• Edoxaban is contraindicated when CrCl <30 mL/min 1

GLP-1 Receptor Agonists (Used for Cardiovascular Risk Reduction)

• Exenatide is contraindicated when eGFR <30 mL/min and not recommended for use 1
• Lixisenatide should be avoided when eGFR <15 mL/min, with limited clinical experience between 15-29 mL/min requiring close monitoring 1

Antidiabetic Agents (Cardiovascular Comorbidity)

• Metformin is absolutely contraindicated when eGFR <30 mL/min/1.73 m² due to significant risk of lactic acidosis 1, 3
• Glyburide (glibenclamide) should be avoided entirely in any degree of renal impairment 1

Medications Requiring Severe Dose Reduction (Not Contraindicated, But Require Caution)

RAAS Antagonists

• ACE inhibitors, ARBs, and aldosterone antagonists are NOT contraindicated at eGFR <30 mL/min—they remain nephroprotective and should not be routinely discontinued 1, 3
• Start at lower doses when eGFR <45 mL/min and assess GFR plus potassium within 1 week of initiation 1
• Discontinue only if GFR declines by >30% or if unmanageable hyperkalemia develops 3

Beta-Blockers

• Reduce dose by 50% when eGFR <30 mL/min/1.73 m², but not contraindicated 1

Digoxin

• Reduce dose based on plasma concentrations when eGFR declines, but not contraindicated 1

Low-Molecular-Weight Heparins (LMWH)

• Enoxaparin requires dose reduction to 1 mg/kg subcutaneously every 24 hours (instead of every 12 hours) when CrCl <30 mL/min 1
• Halve the dose of all LMWHs when eGFR <30 mL/min or consider switching to unfractionated heparin with anti-factor Xa monitoring 1

Warfarin

• Increased bleeding risk when eGFR <30 mL/min—use lower doses and monitor INR closely, but not contraindicated 1

Medications to Avoid (Strong Recommendation Against Use)

NSAIDs

• Avoid NSAIDs when eGFR <30 mL/min/1.73 m² due to risk of acute kidney injury and further renal deterioration 1, 4
• Never combine NSAIDs with ACE inhibitors or ARBs in patients with eGFR <30 mL/min, as this dramatically increases acute kidney injury risk 3, 4

SGLT2 Inhibitors

• Canagliflozin is contraindicated and should be discontinued when eGFR persistently <45 mL/min/1.73 m² 1
• Dapagliflozin is contraindicated when eGFR <30 mL/min/1.73 m² 1
• Empagliflozin should be discontinued when eGFR <30 mL/min/1.73 m² 1

Critical Monitoring Requirements

• Assess renal function prior to initiating any renally-cleared cardiology medication and periodically reassess when clinical situations suggest declining function 2
• Monitor GFR and serum potassium within 1 week of starting or escalating RAAS antagonists 1, 3
• Temporarily suspend RAAS antagonists, diuretics, NSAIDs, and metformin during intercurrent illness (sepsis, dehydration, hypotension) to prevent acute kidney injury 1, 3
• Use aPTT or ECT (not INR) to assess anticoagulation in patients on dabigatran 2
• Monitor anti-factor Xa levels when using LMWH in patients at high bleeding risk with eGFR <30 mL/min 1

Common Pitfalls to Avoid

• Do not rely solely on serum creatinine to assess renal function—it may appear deceptively normal despite reduced GFR, especially in elderly patients or those with reduced muscle mass 3, 4
• Do not assume a 10-20% increase in serum creatinine after starting ACE inhibitors represents acute kidney injury—this is an expected and beneficial hemodynamic effect 3
• Do not automatically discontinue RAAS antagonists when eGFR falls below 30 mL/min, as they remain nephroprotective unless GFR declines by >30% or hyperkalemia develops 1, 3
• Do not combine multiple nephrotoxic agents (NSAIDs, aminoglycosides, contrast media) in patients with eGFR <30 mL/min 4
• Increase frequency of GFR monitoring to at least every 3-6 months when eGFR <60 mL/min/1.73 m² 3