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Database of Antiretroviral Drug Interactions

Interactions with Tadalafil and Antiretrovirals

Antiretroviral (ARV)Dose of ARVDose of TadalafilEffect on ARV LevelsEffect on Tadalafil LevelsPotential Clinical EffectsMechanism of InteractionManagement
Atazanavir727
(ATV)(Reyataz)
--- Not studied; potentially increased tadalafil effects (e.g. hypotension, priapism)--

Initiate tadalafil at 5 mg QD; adjust dose as indicated; not recommended to exceed 10 mg in 72 hour period

Darunavir161
(DRV)(Prezista)
---Not studied; may increase tadalafil levelsIncreased tadalafil effects (eg, hypotension, priapism)Inhibition of CYP450 3A4 by darunavir/ritonavir

Initiate tadalafil at 5 mg QD; adjust dose as indicated; not recommended to exceed 10 mg in 72 hour period

Elvitegravir/cobicistat729, 727
(Genvoya, Stribild)
--No effect expectedNot studied; may increase tadalafil levelsPossible increased tadalafil effects (e.g. hypotension, priapism)-

If initiating tadalafil for pulmonary arterial hypertension in a patient already taking elvitegravir/cobicistat for >1 week: start tadalafil 20 mg once daily and increase to 40 mg as tolerated. If patient with PAH requires initiation of elvitegravir/cobicistat: Stop tadalafil 24 hours prior to starting ART. Wait one week, then initiate tadalafil at 20 mg orally once daily. May increase to 40 mg as tolerated. For erectile dysfunction initiate tadalafil 5 mg dose do not exceed 10 mg in 72 hours.

Elvitegravir/ritonavir-boosted protease inhibitor731, 727
--No effect expectedTadalafil levels increased when administered with ritonavir-boosted protease inhibitors.Increased tadalafil effects (e.g. hypotension, priapism)Inhibition of CYP450 3A4 by ritonavir

If initiating tadalafil for pulmonary arterial hypertension (PAH) in a patient already taking elvitegravir/ritonavir/PI for >1 week: start tadalafil 20 mg once daily and increase to 40 mg as tolerated. If patient with PAH requires initiation of elvitegravir/ritonavir/PI: Stop tadalafil 24 hours prior to starting ART. Wait one week, then initiate tadalafil at 20 mg orally once daily. May increase to 40 mg as tolerated. For erectile dysfunction initiate tadalafil 5 mg dose do not exceed 10 mg in 72 hours.

Lopinavir/ritonavir727, 78
(LPV/r)(Kaletra)
---Not studied; may increase tadalafil levelsIncreased tadalafil effects (eg, hypotension, priapism)Inhibition of CYP450 3A4 by lopinavir/ritonavir

Initiate tadalafil at 5 mg QD; adjust dose as indicated; not recommended to exceed 10 mg in 72 hour period

Alternative Agents:
Sildenafil, vardenafil

Antiretroviral (ARV)Dose of ARVDose of TadalafilEffect on ARV LevelsEffect on Tadalafil LevelsPotential Clinical EffectsMechanism of InteractionManagement
Ritonavir388
(RTV)(Norvir)
200 mg BID20 mg x 1-Tadalafil AUC: increased 124%Increased tadalafil effects (eg, hypotension, priapism)Inhibition of CYP450 3A4 by ritonavir

Initiate tadalafil at 5 mg QD; adjust dose as indicated; not recommended to exceed 10 mg in 72 hour period

Ritonavir388
(RTV)(Norvir)
500 mg or 600 mg BID20 mg x 1-Tadalafil AUC: increased 32%, Cmax: decreased 30%Increased tadalafil effects (eg, hypotension, priapism)Inhibition of CYP450 3A4 by ritonavir

Initiate tadalafil at 5 mg QD; adjust dose as indicated; not recommended to exceed 10 mg in 72 hour period

Tipranavir154
(TPV)(Aptivus)
500 mg BID with 200 mg ritonavir BID x 110 mg x 1-Tadalafil AUC: increased 183%; Cmax decreased 22%-Inhibition of CYP450 by tipranavir/ritonavir (initial phase)

Titrate tadalafil to effect

Tipranavir154
(TPV)(Aptivus)
500 mg BID with 200 mg ritonavir BID x 17 doses10 mg x 1Tipranavir AUC: decreased 15%; Cmax: decreased 19%Tadalafil Cmax: decreased 30%-Induction of CYP450 by tipranavir/ritonavir

Titrate tadalafil to effect

"-" indicates that there are no data available
 78:Kaletra [package insert]. North Chicago, IL: Abbott Laboratories; Oct 2005.
 154:Aptivus [package insert]. Ridgefield, CT: Boehringer Ingelheim Pharmaceuticals, Inc.; Nov 2005.
 161:Prezista [package insert]. Raritan, NJ: Tibotec Therapeutics Inc.; April 2010.
 388:Cialis [package insert]. Indianapolis, IN: Eli Lilly and Company, 2010.
 727:Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents. Department of Health and Human Services. Available at http://aidsinfo.nih.gov/contentfiles/lvguidelines/AdultandAdolescentGL.pdf.
 729:Stribild [package insert]. Foster City, CA: Gilead Sciences; Feb 2016
 731:Vitekta [package insert]. Foster City, CA: Gilead Sciences; Feb 2016