Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
AVANAFIL vs FINASTERIDE AND TADALAFIL
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Selective inhibitor of phosphodiesterase type 5 (PDE5), enhancing nitric oxide-mediated relaxation of smooth muscle in the corpus cavernosum, increasing c GMP levels, and promoting penile erection.
Finasteride is a 5α-reductase inhibitor that inhibits conversion of testosterone to dihydrotestosterone (DHT). Tadalafil is a phosphodiesterase-5 (PDE5) inhibitor that enhances nitric oxide-mediated vasodilation by increasing cyclic guanosine monophosphate (c GMP) in smooth muscle.
Treatment of erectile dysfunction (FDA-approved),Pulmonary arterial hypertension (off-label)
Treatment of benign prostatic hyperplasia (BPH)
100 mg orally once daily, taken 30-60 minutes before sexual activity. Maximum dosing frequency: once daily.
One capsule containing finasteride 5 mg and tadalafil 5 mg orally once daily.
Terminal elimination half-life approximately 6-8 hours. Clinical context: Supports once-daily dosing; steady-state reached within 5 days with no accumulation at FDA-approved dose.
Finasteride: 6-8 hours (elderly ~8 hours); Tadalafil: 17.5 hours (enables once-daily dosing).
Primarily metabolized by CYP3A4, with minor contributions from CYP2C9 and CYP2C19. Subject to first-pass metabolism.
Finasteride is extensively metabolized in the liver via CYP3A4; tadalafil is primarily metabolized by CYP3A4.
Primarily hepatic metabolism via CYP3A4 and CYP2C9, with metabolites excreted in feces (approximately 82-90%) and urine (approximately 6-8% as unchanged drug and minor metabolites).
Finasteride: 57% feces, 39% urine (metabolites); Tadalafil: 36% urine, 61% feces (mostly metabolites).
Approximately 99% bound to plasma proteins, primarily albumin and alpha-1-acid glycoprotein.
Finasteride: 90% bound to albumin and alpha-1-acid glycoprotein; Tadalafil: 94% bound to albumin.
Volume of distribution approximately 200 L (≈ 2.9 L/kg for a 70 kg individual). Clinical meaning: Indicates extensive tissue distribution, with high affinity for genital tissues.
Finasteride: 76 L/kg (1.1 L/kg in elderly); Tadalafil: 63-77 L/kg (extensive tissue distribution).
Oral bioavailability approximately 15-20% due to extensive first-pass metabolism. Absolute bioavailability not determined in humans; based on animal data.
Finasteride: 63% oral (80% relative to IV); Tadalafil: 80% oral (bioavailability unaffected by food).
No dosage adjustment required for mild to moderate renal impairment (Cr Cl ≥30 m L/min). Not recommended for severe renal impairment (Cr Cl <30 m L/min) as safety and efficacy have not been established.
No adjustment for mild-moderate renal impairment (Cr Cl ≥30 m L/min). Avoid in severe renal impairment (Cr Cl <30 m L/min) or on dialysis due to increased tadalafil exposure.
Child-Pugh Class A and B: No dosage adjustment required. Child-Pugh Class C: Not recommended due to lack of data.
Child-Pugh A: no adjustment. Child-Pugh B: limit tadalafil dose to 5 mg (same as given); use caution. Child-Pugh C: avoid use.
Not indicated for use in pediatric patients (age <18 years). Safety and efficacy not established.
Not indicated in pediatric patients; safety and efficacy not established.
No dosage adjustment required solely based on age. However, consider lower starting dose (50 mg) in patients ≥65 years due to potential increased sensitivity and decreased clearance.
No dose adjustment required; monitor for orthostatic hypotension and dizziness, as elderly may be more sensitive to vasodilatory effects.
None.
There is no FDA black box warning for the combination product. Individual components have warnings: Finasteride exposure during pregnancy may cause abnormalities of male external genitalia; Tadalafil is contraindicated in patients taking guanylate cyclase stimulators (e.g., riociguat) and nitrates.
Cardiovascular risk: Not recommended in patients with unstable angina, recent MI (within 90 days), or uncontrolled arrhythmias.,Hypotension: Caution with alpha-blockers or antihypertensives; avoid in those with hypotension (BP <90/50 mm Hg).,Priapism: Advise patients to seek immediate medical attention for erections lasting >4 hours.,Hepatic impairment: Avoid use in severe hepatic impairment (Child-Pugh class C).,Renal impairment: Not recommended in patients on renal dialysis.,Visual effects: Non-arteritic anterior ischemic optic neuropathy (NAION) reported, though rare.
Risk of priapism (tadalafil); sudden hearing loss (tadalafil); orthostatic hypotension with concomitant antihypertensives; prostate-specific antigen (PSA) level reduction (finasteride); risk of high-grade prostate cancer (finasteride); use in women of childbearing potential (finasteride teratogenicity).
Concomitant use of organic nitrates (e.g., nitroglycerin, isosorbide mononitrate/dinitrate),Concomitant use of guanylate cyclase stimulators (e.g., riociguat),Hypersensitivity to avanafil or any component of the formulation,Severe hepatic impairment (Child-Pugh class C),Recent stroke or myocardial infarction (within 6 months),Patients with hypotension (BP <90/50 mm Hg)
Hypersensitivity to finasteride or tadalafil; concurrent use of nitrates or guanylate cyclase stimulators (e.g., riociguat); women who are or may become pregnant (finasteride teratogenicity).
Avanafil can be taken with or without food. However, a high-fat meal may delay absorption and reduce peak plasma concentration, potentially prolonging time to onset. Grapefruit juice may increase avanafil levels; avoid concurrent consumption.
Avoid grapefruit and grapefruit juice as they increase tadalafil plasma concentrations. Alcohol may potentiate hypotension and dizziness. High-fat meals may delay tadalafil absorption but do not reduce efficacy.
No adequate and well-controlled studies in pregnant women. Animal studies show no evidence of teratogenicity at exposures up to 18 times the MRHD. Risk cannot be ruled out; use only if clearly needed.
Finasteride: Contraindicated in pregnancy due to risk of hypospadias in male fetuses (Category X). Tadalafil: Category B; no fetal harm in animal studies, but insufficient human data. Avoid combination in pregnant women.
Not known if excreted in human milk. No data on M/P ratio. Caution advised; consider developmental benefits of breastfeeding vs potential adverse effects.
Finasteride: Excreted in breast milk (M/P ratio unknown); not recommended. Tadalafil: Presence in breast milk unknown; avoid due to potential adverse effects.
No specific dose adjustments established; use lowest effective dose if indicated. Pharmacokinetic changes in pregnancy unknown; monitor for efficacy and adverse effects.
Contraindicated in pregnancy; pharmacokinetic changes in pregnancy do not apply as use is not recommended. No dose adjustment applicable.
Avanafil is a rapid-onset PDE5 inhibitor with a Tmax of 30-45 minutes, making it suitable for on-demand use. It has minimal interaction with alpha-blockers compared to other PDE5 inhibitors, but caution is still advised. Avoid use in patients taking nitrates or those with severe hepatic impairment (Child-Pugh C). Its short half-life (5 hours) reduces the duration of side effects like headache and flushing.
Finasteride and tadalafil combination is used for benign prostatic hyperplasia (BPH). Tadalafil may cause priapism; advise immediate medical attention for erections lasting >4 hours. Finasteride decreases serum PSA by ~50%; double PSA values for interpretation. Avoid coadministration with strong CYP3A4 inhibitors (e.g., ketoconazole) due to increased tadalafil exposure. Tadalafil is contraindicated with nitrates due to severe hypotension. Assess cardiovascular stability before prescribing tadalafil.
Take avanafil approximately 30 minutes before sexual activity, with or without food.,Do not take more than one dose in a 24-hour period.,Seek emergency medical attention if you experience an erection lasting more than 4 hours (priapism) or sudden vision loss.,Avoid alcohol or limit to small amounts as it may increase side effects like dizziness or hypotension.,Inform your doctor if you are taking any medications, especially nitrates, alpha-blockers, or antihypertensives.
Take the medication at the same time daily with or without food.,Seek emergency care for erections lasting longer than 4 hours.,Inform your doctor about all medications, especially nitrates or alpha-blockers.,Finasteride may reduce PSA levels; do not stop taking before PSA testing without consulting your doctor.,Avoid grapefruit juice as it may increase side effects.,Tadalafil may cause dizziness or syncope; avoid driving if affected.
"Avanafil, a phosphodiesterase type 5 (PDE5) inhibitor, enhances the vasodilatory effects of nitric oxide by increasing cyclic guanosine monophosphate (cGMP) levels. Acebutolol, a cardioselective beta-blocker, reduces cardiac output and sympathetic outflow. Concurrent use may lead to additive hypotension, particularly during initiation or dose escalation, potentially causing dizziness, syncope, or orthostatic hypotension."
"Cobicistat is a potent inhibitor of CYP3A4, the primary enzyme responsible for metabolizing avanafil. Co-administration significantly increases avanafil's systemic exposure, potentially doubling its plasma concentration and half-life. This elevated exposure raises the risk of avanafil-associated adverse effects, such as hypotension, priapism, and visual disturbances, and may also enhance cobicistat's own serum levels due to shared metabolic pathways, increasing the likelihood of nephrotoxicity and other protease inhibitor-related toxicities."
"Isavuconazonium is a prodrug of isavuconazole, a triazole antifungal that inhibits CYP3A4 and CYP3A5. Coadministration with avanafil, a PDE5 inhibitor metabolized primarily by CYP3A4, can increase avanafil exposure due to reduced clearance. This may elevate the risk of avanafil-associated adverse effects such as hypotension, priapism, and visual disturbances."
"Tadalafil, a phosphodiesterase-5 (PDE5) inhibitor, potentiates the hypotensive effect of trandolapril, an angiotensin-converting enzyme (ACE) inhibitor, by enhancing cyclic guanosine monophosphate (cGMP)-mediated vasodilation. This additive hemodynamic effect can lead to symptomatic hypotension, particularly in patients with volume depletion, pre-existing low blood pressure, or those on multiple antihypertensives. Clinically, this interaction manifests as a risk of excessive blood pressure reduction, especially when tadalafil is taken within 4-6 hours of trandolapril administration."
"Posaconazole, an azole antifungal, is a potent inhibitor of CYP3A4, while tadalafil is a CYP3A4 substrate. Coadministration significantly increases tadalafil exposure, leading to elevated risk of adverse effects such as hypotension, syncope, and priapism. The interaction is well-documented and requires dose adjustment or avoidance."
"Tadalafil, a phosphodiesterase-5 (PDE5) inhibitor, potentiates the vasoconstrictive and hypertensive effects of xylometazoline, an alpha-1 adrenergic receptor agonist. This occurs through tadalafil's inhibition of cGMP degradation in vascular smooth muscle, which counteracts the normal nitric oxide-mediated vasodilation and enhances the pressor response to alpha-agonists. Clinically, this interaction can lead to excessive and prolonged increases in blood pressure, potentially resulting in hypertensive crisis, especially in patients with underlying cardiovascular conditions."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about AVANAFIL vs FINASTERIDE AND TADALAFIL, answered by our medical review team.
AVANAFIL is a PDE5 Inhibitor that works by Selective inhibitor of phosphodiesterase type 5 (PDE5), enhancing nitric oxide-mediated relaxation of smooth muscle in the corpus cavernosum, increasing c GMP levels, and promoting penile erection.. FINASTERIDE AND TADALAFIL is a PDE5 Inhibitor that works by Finasteride is a 5α-reductase inhibitor that inhibits conversion of testosterone to dihydrotestosterone (DHT). Tadalafil is a phosphodiesterase-5 (PDE5) inhibitor that enhances nitric oxide-mediated vasodilation by increasing cyclic guanosine monophosphate (c GMP) in smooth muscle.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between AVANAFIL and FINASTERIDE AND TADALAFIL depend on the specific clinical indication. These are both PDE5 Inhibitor agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of AVANAFIL is: 100 mg orally once daily, taken 30-60 minutes before sexual activity. Maximum dosing frequency: once daily.. The standard adult dose of FINASTERIDE AND TADALAFIL is: One capsule containing finasteride 5 mg and tadalafil 5 mg orally once daily.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
A moderate-severity drug interaction has been identified when combining AVANAFIL and FINASTERIDE AND TADALAFIL. The risk or severity of adverse effects can be increased when Tadalafil is combined with Avanafil. Consult your prescriber before combining these medications.
The maternal-fetal safety profiles differ. AVANAFIL is classified as Category C. No adequate and well-controlled studies in pregnant women. Animal studies show no evidence of teratogenicity at exposures up to 18 times the MRHD. Risk cannot be ruled out; use onl. FINASTERIDE AND TADALAFIL is classified as Category A/B. Finasteride: Contraindicated in pregnancy due to risk of hypospadias in male fetuses (Category X). Tadalafil: Category B; no fetal harm in animal studies, but insufficient human da. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.