Skip to main content

Drug Interactions between boceprevir and tadalafil

This report displays the potential drug interactions for the following 2 drugs:

Edit list (add/remove drugs)

Interactions between your drugs

Major

tadalafil boceprevir

Applies to: tadalafil and boceprevir

CONTRAINDICATED: Coadministration with the hepatitis C virus (HCV) NS3/4A protease inhibitors, boceprevir and telaprevir, may significantly increase the plasma concentrations of tadalafil. The mechanism involves inhibition of CYP450 3A4, the isoenzyme primarily responsible for the metabolic clearance of tadalafil. The interaction has not been specifically studied with either boceprevir or telaprevir, but has been reported with other potent CYP450 3A4 inhibitors such as ketoconazole or ritonavir. According to the product labeling for tadalafil, administration of a single 20 mg dose during treatment with ketoconazole (400 mg daily) increased the tadalafil peak plasma concentration (Cmax) and systemic exposure (AUC) by 22% and 312%, respectively, compared to administration alone. A lower dosage of ketoconazole (200 mg daily) increased the Cmax and AUC of a single 10 mg dose of tadalafil by 15% and 107%, respectively. Ritonavir (200 mg twice a day) increased the AUC of a single 20 mg dose of tadalafil by 124% without changing the Cmax.

MANAGEMENT: A safe and effective dosage of tadalafil has not been established for the treatment of pulmonary arterial hypertension when used in the presence of HCV NS3/4A protease inhibitors. Due to the potential for increased tadalafil-associated adverse events including visual disturbances, hypotension, prolonged erection and syncope, this use is considered contraindicated. When used for erectile dysfunction, the maximum dosage of tadalafil should not exceed a single dose of 10 mg in any given 72-hour period. Patients should be advised to promptly notify their doctor if they experience pain or tightness in the chest or jaw, irregular heartbeat, nausea, shortness of breath, visual disturbances, syncope, or prolonged erection (greater than 4 hours).

References

  1. (2003) "Product Information. Cialis (tadalafil)." Lilly, Eli and Company
  2. (2011) "Product Information. Victrelis (boceprevir)." Schering-Plough Corporation
  3. (2011) "Product Information. Incivek (telaprevir)." Vertex Pharmaceuticals

Switch to consumer interaction data

Drug and food interactions

Moderate

tadalafil food

Applies to: tadalafil

GENERALLY AVOID: Additive hypotensive effects may occur when phosphodiesterase-5 (PDE5) inhibitors such as tadalafil are used with alcohol, as both are mild systemic vasodilators. In clinical pharmacology studies, more subjects administered alcohol at a dose of 0.7 g/kg (equivalent to approximately 6 ounces of 80-proof vodka in an 80-kg male; consumed within 10 minutes in study subjects, providing blood alcohol levels of 0.08%) in combination with tadalafil 10 or 20 mg single doses had clinically significant decreases in blood pressure than with alcohol alone. There were reports of postural dizziness, and orthostatic hypotension was observed in some. When tadalafil 20 mg was administered with alcohol at a lower dose of 0.6 g/kg (equivalent to approximately 4 ounces of 80-proof vodka in an 80-kg male), orthostatic hypotension was not observed, dizziness occurred with similar frequency relative to alcohol alone, and the hypotensive effects of alcohol were not potentiated. Neither tadalafil nor alcohol affected the plasma concentrations of the other.

GENERALLY AVOID: Coadministration with grapefruit juice is likely to increase the plasma concentrations of tadalafil, which is primarily metabolized by CYP450 3A4. However, the interaction has not been studied. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit.

MANAGEMENT: Patients taking tadalafil should avoid consuming large amounts of alcohol (for example, 5 units or more), which may increase the potential for orthostatic signs and symptoms including increase in heart rate, decrease in standing blood pressure, dizziness, and headache. It may also be appropriate to avoid consuming large amounts of grapefruit juice.

References

  1. (2003) "Product Information. Cialis (tadalafil)." Lilly, Eli and Company
  2. (2009) "Product Information. Adcirca (tadalafil)." United Therapeutics Corporation

Switch to consumer interaction data

Moderate

boceprevir food

Applies to: boceprevir

ADJUST DOSING INTERVAL: Food significantly enhances the oral bioavailability of boceprevir. When given at 800 mg three times daily with food, boceprevir exposure increased by up to 65% relative to administration in the fasting state. The bioavailability of boceprevir was similar regardless of meal type (e.g., high-fat versus low-fat) or whether taken 5 minutes prior to eating, during a meal, or immediately following completion of the meal. Therefore, boceprevir may be taken without regard to either meal type or timing of the meal.

MANAGEMENT: To ensure maximal oral absorption, boceprevir should be administered with a meal or light snack.

References

  1. (2011) "Product Information. Victrelis (boceprevir)." Schering-Plough Corporation

Switch to consumer interaction data

Therapeutic duplication warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.

See also

Report options

Loading...
QR code containing a link to this page

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer