Severe. These medicines may interact and cause very harmful effects and are usually not taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
Boceprevir and telaprevir may slow down how quickly your liver processes sildenafil and tadalafil.
What might happen:
Your blood levels of sildenafil or tadalafil may increase and cause harmful effects.
What you should do about this interaction:
Let your healthcare professional (e.g. doctor or pharmacist) know right away that you are taking these medicines together and the condition for which you are taking sildenafil or tadalafil. These medicines are not usually used together in patients with a condition called pulmonary arterial hypertension (PAH). Contact your doctor if you experience a painful or prolonged erection, fainting or dizziness, or changes in vision. The dose of your sildenafil or tadalafil may need adjusting.Your healthcare professionals (e.g. doctor or pharmacist) may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
1.Victrelis (boceprevir) US prescribing information. Schering Corporation July, 2014.
2.Incivek (telaprevir) US prescribing information. Vertex Pharmaceuticals Incorporated October, 2013.