Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
FINASTERIDE AND TADALAFIL vs ADCIRCA
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
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.
Phosphodiesterase-5 (PDE5) inhibitor; increases c GMP in pulmonary vascular smooth muscle, leading to vasodilation.
Treatment of benign prostatic hyperplasia (BPH)
Treatment of pulmonary arterial hypertension (PAH) (WHO Group I) to improve exercise capacity and delay clinical worsening.,Off-label: Erectile dysfunction (not FDA-approved for this indication in the context of PAH).
One capsule containing finasteride 5 mg and tadalafil 5 mg orally once daily.
10 mg orally three times daily.
Finasteride: 6-8 hours (elderly ~8 hours); Tadalafil: 17.5 hours (enables once-daily dosing).
Terminal half-life: 10–15 hours in healthy adults; prolonged in hepatic impairment (Child-Pugh B/C: up to 30 hours); clinical context: supports twice-daily dosing
Finasteride is extensively metabolized in the liver via CYP3A4; tadalafil is primarily metabolized by CYP3A4.
Primarily metabolized by CYP3A4 (major) and CYP2C9 (minor) hepatic enzymes.
Finasteride: 57% feces, 39% urine (metabolites); Tadalafil: 36% urine, 61% feces (mostly metabolites).
Renal: ~70% (metabolites and unchanged drug), Fecal: ~20%, Biliary: minor
Finasteride: 90% bound to albumin and alpha-1-acid glycoprotein; Tadalafil: 94% bound to albumin.
96% bound to albumin and alpha-1-acid glycoprotein
Finasteride: 76 L/kg (1.1 L/kg in elderly); Tadalafil: 63-77 L/kg (extensive tissue distribution).
Vd: 0.4–0.7 L/kg; suggests distribution into total body water and moderate tissue binding
Finasteride: 63% oral (80% relative to IV); Tadalafil: 80% oral (bioavailability unaffected by food).
Oral: 80%; absolute bioavailability: 50% due to first-pass metabolism
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.
No dose adjustment required for mild to moderate renal impairment; avoid use in severe impairment (Cr Cl <30 m L/min) 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.
Mild to moderate hepatic impairment (Child-Pugh A or B): 10 mg orally once daily; severe hepatic impairment (Child-Pugh C): contraindicated.
Not indicated in pediatric patients; safety and efficacy not established.
Not established for patients <18 years.
No dose adjustment required; monitor for orthostatic hypotension and dizziness, as elderly may be more sensitive to vasodilatory effects.
No specific dose adjustment, but caution due to increased sensitivity; monitor renal function.
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.
Do not use in patients taking nitrates (regularly or intermittently) due to risk of severe hypotension.
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).
Risk of hypotension, especially with nitrates or alpha-blockers.,Hematologic effects: increased risk of bleeding due to antiplatelet activity; caution with bleeding disorders or anticoagulants.,Vision loss: non-arteritic anterior ischemic optic neuropathy (NAION) has been reported; discontinue if sudden vision loss occurs.,Hearing loss: sudden decrease or loss of hearing; may be accompanied by tinnitus or dizziness.,Use caution in patients with left ventricular outflow obstruction (e.g., aortic stenosis) or severely impaired autonomic control of blood pressure.,Dose adjustment required with strong CYP3A4 inhibitors (e.g., ketoconazole, ritonavir).
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).
Concomitant use of nitrates (any form) or nitric oxide donors.,Concomitant use with riociguat or other guanylate cyclase stimulators.,Known hypersensitivity to tadalafil or any component of the product.,Severe hepatic impairment (Child-Pugh class C).
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.
Avoid grapefruit and grapefruit juice as they may increase tadalafil levels and risk of side effects. No other significant food interactions. High-fat meals may delay absorption but do not require dose adjustment.
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.
Pregnancy Category B. Animal studies have not demonstrated fetal risk, but there are no adequate and well-controlled studies in pregnant women. First trimester: risk cannot be ruled out; use only if clearly needed. Second and third trimesters: no known fetal risks, but caution advised due to maternal hypotension risk.
Finasteride: Excreted in breast milk (M/P ratio unknown); not recommended. Tadalafil: Presence in breast milk unknown; avoid due to potential adverse effects.
Not recommended. Excretion in human milk unknown. M/P ratio not established. Risk of hypotension in neonate. Alternative feeding method advised during therapy and for 48 hours after last dose.
Contraindicated in pregnancy; pharmacokinetic changes in pregnancy do not apply as use is not recommended. No dose adjustment applicable.
No specific pharmacokinetic data in pregnancy. Standard dose (40 mg orally once daily) recommended. Monitor for hypotension; dose adjustment not routinely required unless maternal hypotension develops.
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.
Adcirca (tadalafil) is a PDE5 inhibitor indicated for pulmonary arterial hypertension (PAH) to improve exercise ability. It is dosed at 40 mg once daily, not as needed. Avoid use with nitrates due to risk of severe hypotension. Monitor for vision loss (non-arteritic anterior ischemic optic neuropathy) and hearing loss. Use caution in patients with hepatic impairment (Child-Pugh class B: reduce dose; class C: contraindicated). Dose adjustment required with potent CYP3A4 inhibitors (e.g., ketoconazole: reduce to 20 mg). Not recommended for severe renal impairment (Cr Cl <30 m L/min) or on hemodialysis.
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.
Take Adcirca exactly as prescribed, 40 mg once daily, at the same time each day. Do not take it as needed for erectile dysfunction.,Do not take Adcirca if you are taking any form of nitrate medication (e.g., nitroglycerin) or recreational drugs called 'poppers' (amyl nitrate) as this can cause a sudden dangerous drop in blood pressure.,Seek immediate medical attention if you experience sudden vision loss or decrease in hearing, as these may be signs of a serious side effect.,Avoid drinking large amounts of alcohol (e.g., 3 or more drinks) within a short time while taking Adcirca, as it may increase the risk of dizziness, lightheadedness, and fainting.,Inform your healthcare provider about all medications you take, including prescription, over-the-counter, and herbal products, especially alpha-blockers, erythromycin, or ritonavir.,Adcirca may cause dizziness. Do not drive or operate machinery until you know how the medicine affects you.
"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."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about FINASTERIDE AND TADALAFIL vs ADCIRCA, answered by our medical review team.
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.. ADCIRCA is a PDE5 Inhibitor that works by Phosphodiesterase-5 (PDE5) inhibitor; increases c GMP in pulmonary vascular smooth muscle, leading to vasodilation.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between FINASTERIDE AND TADALAFIL and ADCIRCA 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 FINASTERIDE AND TADALAFIL is: One capsule containing finasteride 5 mg and tadalafil 5 mg orally once daily.. The standard adult dose of ADCIRCA is: 10 mg orally three times daily.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between FINASTERIDE AND TADALAFIL and ADCIRCA in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. 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. ADCIRCA is classified as Category C. Pregnancy Category B. Animal studies have not demonstrated fetal risk, but there are no adequate and well-controlled studies in pregnant women. First trimester: risk cannot be rule. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.