Can Eliquis (apixaban) be taken with Macrobid (nitrofurantoin)?

Apixaban (Eliquis) and Nitrofurantoin (Macrobid) Interaction

Yes, Eliquis (apixaban) can generally be taken safely with Macrobid (nitrofurantoin) as there is no significant direct drug interaction between these two medications.

Pharmacological Basis for Safety

Apixaban is primarily metabolized via the liver through CYP3A4-dependent pathways, with renal elimination accounting for approximately 27% of total drug clearance 1. Nitrofurantoin, on the other hand, does not significantly affect CYP3A4 enzymes or P-glycoprotein transporters that are involved in apixaban metabolism.

Key Considerations:

1. Mechanism of action differences:

   • Apixaban is a direct factor Xa inhibitor that prevents blood clotting 2
   • Nitrofurantoin is an antimicrobial agent that acts against urinary tract pathogens 3

2. Metabolism pathways:

   • No evidence suggests that nitrofurantoin interferes with the CYP3A4 or P-glycoprotein pathways that metabolize apixaban
   • Unlike many other antibiotics, nitrofurantoin is not known to be a significant inhibitor or inducer of drug-metabolizing enzymes

Clinical Considerations

Renal Function Monitoring

Both medications have considerations related to renal function:

• Apixaban should be used with caution in patients with moderate renal impairment (CrCl 30-50 mL/min) 1
• Nitrofurantoin is contraindicated in patients with severe renal impairment (CrCl <30 mL/min) due to potential toxicity and reduced efficacy 4

Potential Concerns

While there is no direct interaction, be aware of:

1. Bleeding risk assessment:

   • Monitor for any signs of unusual bleeding while on apixaban
   • Concomitant use of multiple medications may increase overall bleeding risk, though nitrofurantoin itself does not enhance this risk 5

2. Pulmonary considerations:

   • Nitrofurantoin rarely can cause pulmonary toxicity, particularly with long-term use 4
   • If a patient develops respiratory symptoms while on both medications, consider nitrofurantoin as a potential cause rather than attributing symptoms to an interaction

Practical Recommendations

1. No dosage adjustments needed:

   • Standard dosing of both medications can be maintained when used together

2. Monitoring:

   • Regular assessment of renal function is advisable when using either medication
   • No special additional monitoring is required specifically due to the combination

3. Patient education:

   • Advise patients to report any unusual bleeding or respiratory symptoms
   • Remind patients to avoid taking OTC medications (especially NSAIDs like ibuprofen or naproxen) without consulting their healthcare provider, as these may interact with apixaban 6

Conclusion

The combination of apixaban and nitrofurantoin does not present any known significant drug interaction concerns. The medications work through different mechanisms and metabolic pathways, allowing for concurrent use without special precautions beyond those normally associated with each individual medication.