https://interactions.guidetherapeutiquevih.com/en/interaction-details?id=13056

Elvitegravir / Cobicistat

Tadalafil (Cialis)

Modification of dose and/or administration time necessary.

No pharmaceutical opinion available for this interaction.

Mechanism

Elvitegravir / Cobicistat can inhibit the metabolism (CYP 3A4) and increase the plasma concentration of Tadalafil (Cialis).

Elvitegravir / Cobicistat

Pharmacodynamic effects

–

Recommendations

–

Alternative solution(s)

–

Tadalafil (Cialis)

Pharmacodynamic effects

Possible increase of adverse effects.

Recommendations

Use as needed: start at 10 mg every two days and if needed increase to 20 mg, maximum of 3 times a week.

If the 10 mg dose is not tolerated, tadalafil treatment should be stopped.

Once-daily use: usual dose of 5 mg QD could be used. If intolerance, reduce the dose to 2.5 mg QD.

Monitor closely clinical efficacy and appearance of adverse effects.

Give extra caution to patients with hepatic or renal insufficiency, or older than 65 years.

Alternative solution(s)

–

Monitor

Tadalafil toxicity: hypotension, tachycardia, headache, dizziness, flushing, visual changes (difficulty distinguishing blue and green) and syncope.

Tests

–

Pharmacokinetic parameters

–

Comment

Studies confirming increased PDE-5 inhibitor concentrations with coadministration of PIs and pharmacokinetic enhancers have been well documented since these ED agents first became available for clinical use. At least two published case reports describe deaths associated with interactions involving PDE-5 inhibitors and a PI in combination with ritonavir. Such consequences make recommendations for PDE-5 inhibitor dose reduction and slow dose titration essential when these ED agents are co-prescribed with strong CYP 3A4 inhibitors such as PIs, ritonavir, or cobicistat.

Tadalafil AUC is increased by 124% when using a dose of tadalafil 20 mg associated with ritonavir (Norvir) 200 mg BID. Also with ketoconazole (400 mg), a potent CYP3A4 inhibitor, associated with tadalafil 20 mg: there is an increase in tadalafil AUC and Cmax of 312% and 22% respectively. With ketoconazole (200 mg) and a dose of tadalafil 10 mg, rather there is an increase of 107% and 15% in tadalafil AUC and Cmax.

Ref #3726 : In this cohort study of 235 men with erectile dysfunction receiving treatment with a PDE-5 inhibitor and antiretroviral therapy with potential for interactions. The majority of men receiving ART boosted with ritonavir or cobicistat demonstrated interactions.

Ref #2914: case report of recurrent priapism with combination of tadalafil and fosamprenavir/ritonavir.

Precautions: hepatic and renal impairment (CrCl 31-50 ml/min: increases 2 times tadalafil AUC). Age >65 years may also increase tadalafil concentration.

See also tadalafil (Adcirca).

Comment
Reference
  • 1383
    Tadalafil (Cialis), Eli Lilly, Ontario, Canada, 22 novembre 2016.
  • 2376
    Tadalafil (Adcirca), Eli Lilly, Ontario, Canada, 22 novembre 2016.
  • 3281
    Elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (Genvoya), Gilead, Ontario, Canada, 6 août 2021.
  • 2570
    Elvitegravir/cobicistat/emtricitabine/tenofovir (Stribild), Gilead, Ontario, Canada, 17 septembre 2018.
  • 3726
    Cota JM, Benavides TM, Fields JD, Jansen N, Ganesan A, et al. High frequency of potential phosphodiesterase type 5 inhibitor drug interactions in males with HIV infection and erectile dysfunction. PLoS One. 2021 May 6; 16 (5): e0250607.
  • 2914
    Loulergue P, Gaillard R, Mir O. Interaction involving tadalafil and CYP3A4 inhibition by ritonavir. Scand J Infect Dis 2011 Mar; 43(3): 239-40.
  • 3727
    Hall MC, Ahmad S. Interaction between sildenafil and HIV-1 combination therapy. Lancet 1999. June 12; 353(9169) : 2071-2072.
  • 3728
    Kobayashi M, Takata Y, Goseki Y, Mizukami H, Hara S, Kuriiwa F, et al. A sudden cardiac death induced by sildenafil and sexual activity in an HIV patient with drug interaction, cardiac early repolarization, and arrhythmogenic right ventricular cardiomyopathy. Int J Cardiol 2015; 179: 421-423.