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PDE5 Inhibitors (e.g., Sildenafil, Tadalafil, Vardenafil) and Grapefruit Juice

INTERACTION STATUS
Potential interaction

The combination may require the dose, timing, or monitoring adjustments described below.

PDE5 Inhibitors (e.g., Sildenafil, Tadalafil, Vardenafil)
Grapefruit Juice
Clinical Summary

Grapefruit juice can increase the blood levels of erectile dysfunction medications like sildenafil and tadalafil, potentially enhancing their effects and side effects.

Important Considerations

Interaction can last up to 24-72 hours after grapefruit juice consumption due to enzyme inhibition persistence.

Effect varies by specific PDE5 inhibitor; strongest with sildenafil and tadalafil.

Even small amounts (e.g., one glass) can cause significant interaction.

Patients with cardiovascular conditions should be especially cautious.

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Answer context

Evidence: Not yet assessed

Last reviewed: Review date unavailable.


Who this answer applies to

Situation details are not specified.

Scope and limitations
Evidence limitations

Limitations have not yet been documented. Personal history, exact amount and timing, other medicines, allergies, and local guidance may change the answer.

Medical Analysis
Mechanism

Grapefruit juice contains furanocoumarins that inhibit the CYP3A4 enzyme in the intestines, which is responsible for metabolizing PDE5 inhibitors, leading to reduced drug clearance and higher systemic exposure.

Clinical Impact & Risks

Elevated plasma concentrations may intensify adverse effects such as headache, flushing, dizziness, hypotension, visual disturbances, and in rare cases, priapism or severe cardiovascular events.

Management & Recommendations

Avoid or limit grapefruit juice consumption while taking PDE5 inhibitors; if unavoidable, monitor for enhanced effects and consult a healthcare provider for dose adjustments or alternative timing.

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What to do now

Practical next steps, warning signs, and when to seek help.

Immediate steps

Medication safeguard: Do not start, stop, or change a prescribed medicine without the prescriber's direction. Follow the dose, timing, and monitoring guidance below. Scenario guidance: Avoid or limit grapefruit juice consumption while taking PDE5 inhibitors; if unavoidable, monitor for enhanced effects and consult a healthcare provider for dose adjustments or alternative timing.

Warning signs

Scenario-specific warning signs have not been documented. For trouble breathing, collapse or unconsciousness, a seizure, or immediate danger, contact local emergency services or poison control now.

When to get help

Ask a pharmacist or prescriber for a personalized interaction check. For severe symptoms or immediate danger, contact local emergency services or poison control now.
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