Tadalafil and Nicorandil: Absolute Contraindication
No, tadalafil cannot be taken with nicorandil—this combination is absolutely contraindicated due to the severe risk of life-threatening hypotension. 1
The Critical Contraindication
Co-administration of nicorandil with phosphodiesterase-5 inhibitors (including tadalafil) is contraindicated because of a high risk of severe hypotension (Class I, Level C recommendation). 1
The FDA label for tadalafil explicitly warns that at least 48 hours must elapse after the last dose of tadalafil before any nitrate or nitrate-like medication (including nicorandil) can be administered, and even then only under close medical supervision with hemodynamic monitoring. 2
Nicorandil possesses a nitrate moiety in its chemical structure and functions partly through nitrate-like mechanisms, making it pharmacologically similar to organic nitrates in terms of this dangerous interaction. 3, 4
Why This Combination Is Dangerous
Both nicorandil and tadalafil cause vasodilation through complementary mechanisms—nicorandil through both nitrate effects and potassium channel activation, while tadalafil inhibits phosphodiesterase-5. 3
When combined, these vasodilatory effects are additive and can produce profound, potentially fatal hypotension that may be refractory to standard resuscitation measures. 1, 2
The prolonged half-life of tadalafil (up to 36 hours for clinical effects) means this risk persists long after the dose is taken. 2
Clinical Management for This Patient
If the patient requires treatment for erectile dysfunction while taking nicorandil, the nicorandil must be discontinued and an alternative antianginal agent substituted before any PDE-5 inhibitor can be considered. 1
Alternative antianginal options that do not contraindicate PDE-5 inhibitors include:
The ESC guidelines explicitly state that phosphodiesterase-5 inhibitors are not contraindicated in patients with heart failure or angina EXCEPT when patients are taking nitrates or nitrate-like drugs. 5
Important Caveat About Timing
Even after stopping nicorandil, sufficient washout time must occur before initiating tadalafil—the exact duration depends on nicorandil's elimination kinetics and the patient's renal function. 1
Conversely, if a patient on tadalafil develops acute angina requiring nicorandil or nitrates, at minimum 48 hours must pass since the last tadalafil dose, and administration should only occur in a monitored setting where hypotension can be managed. 2
The Bottom Line
This is not a relative contraindication or a "use with caution" scenario—it is an absolute contraindication based on life-threatening drug interaction risk. The patient's angina regimen must be modified to exclude nicorandil before tadalafil can be safely prescribed. 1, 2