Naltrexone and Tadalafil: Safety of Concurrent Use
Yes, naltrexone can be safely used with tadalafil (Cialis) as there are no significant drug interactions between these medications. 1
Mechanism of Action and Interaction Profile
- Naltrexone is an opioid antagonist primarily used for alcohol dependence and opioid dependence, working by blocking opioid receptors 2
- Tadalafil is a phosphodiesterase-5 inhibitor used for erectile dysfunction that works through a completely different mechanism 3
- No documented interactions exist between these two medications in the available clinical guidelines 1
Important Considerations for Naltrexone Use
- Naltrexone should not be used concomitantly with opioid medications, as it blocks their effects and can precipitate withdrawal in opioid-dependent patients 1, 4
- For patients requiring procedures with opioid analgesia, oral naltrexone should be discontinued 2-3 days prior to allow for effective pain management 1
- Common side effects of naltrexone include constipation, nausea, headache, and xerostomia (dry mouth) 1
- Naltrexone may cause elevated heart rate and blood pressure, particularly when used in combination formulations like naltrexone-bupropion ER 1
Important Considerations for Tadalafil Use
- Tadalafil has demonstrated long-term safety and tolerability in clinical studies lasting up to 24 months 3
- Common side effects include headache, dyspepsia, nasopharyngitis, and back pain 3
- No significant laboratory, electrocardiographic findings, or vital sign changes were attributed to tadalafil in long-term studies 3
Clinical Monitoring Recommendations
- When using naltrexone (especially in combination with bupropion), blood pressure and heart rate should be monitored periodically, particularly in the first 12 weeks of treatment 1
- Liver function tests should be monitored at baseline and periodically during naltrexone treatment due to potential hepatic effects at higher doses 4
- No special monitoring is required specifically for the combination of naltrexone and tadalafil beyond what would be recommended for each medication individually 1, 3
Potential Pitfalls to Avoid
- Be aware that naltrexone can cause false-positive urine drug screens for oxycodone due to its metabolite noroxymorphone 2
- Do not confuse naltrexone with methylnaltrexone or naldemedine, which are peripherally acting mu-opioid receptor antagonists used for opioid-induced constipation with different clinical considerations 1
- Patients should be informed that naltrexone will block the effects of any opioid medications, which is particularly important in emergency situations requiring pain management 1, 4