Phosphodiesterase-5 (PDE5) inhibitor

Adcirca (tadalafil)

An approved treatment for Pulmonary Arterial Hypertension.

FDA Approved (2009)by Eli Lilly (marketed in the US by United Therapeutics)
Preclinical
Phase 1
Phase 2
Phase 3
Approved
2009
Drug facts

The same compound appears under different names depending on the context. Here is how to identify Tadalafil wherever you encounter it, plus the key facts at a glance.

Generic name
Tadalafil
Brand name
Adcirca
Drug class
Phosphodiesterase-5 (PDE5) inhibitor
Manufacturer
Eli Lilly (marketed in the US by United Therapeutics)
How it's taken
Taken by mouth as 40 mg (two 20 mg tablets) once daily, with or without food.

A once-daily PDE5 inhibitor for PAH that offers dosing convenience over sildenafil (which requires 3 times daily dosing). The same active ingredient as Cialis, marketed as Adcirca for PAH.

Where Tadalafil fits

Once-daily oral PDE5 inhibitor for PAH, offering dosing convenience over three-times-daily sildenafil. Often interchangeable with sildenafil based on patient preference.

How Tadalafil works

Like sildenafil, tadalafil blocks PDE5 to prevent the breakdown of cGMP, allowing pulmonary blood vessels to stay relaxed and dilated. Tadalafil has a longer half-life (about 35 hours in people with pulmonary hypertension versus about 4 hours for sildenafil), which allows once-daily dosing and provides more consistent blood vessel relaxation throughout the day and night.

Mechanism: Long-acting PDE5 inhibitor that sustains relaxation of pulmonary blood vessels throughout the day

Side effects and safety

What patients report

Common side effects include headache, muscle aches, flushing, nasal congestion, indigestion, and back pain. Must not be combined with nitrates or riociguat. Hearing and vision changes should be reported immediately. Low blood pressure can occur. The label also warns against taking it with Cialis or other PDE5 inhibitors, says it is not recommended for people with pulmonary veno-occlusive disease, and advises getting emergency care for an erection that lasts more than 4 hours.

This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.

Taking Tadalafil

Taken by mouth as 40 mg (two 20 mg tablets) once daily, with or without food. The dose should not be split across the day. The once-daily dosing is an advantage over sildenafil's 3 times daily schedule. Generic versions are available.

Availability and cost

Generic available

Generic versions may be available at a lower cost. Ask your pharmacist.

Why it costs what it costs

PDE5 inhibitor available in generic form with once-daily dosing convenience. Well-established small molecule originally developed for erectile dysfunction.

Help paying for Adcirca

Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.

Your insurance
From the drugmaker
Adcirca (Tadalafil)
  • Copay help

    Most eligible commercially insured patients may pay as little as $0 per ADCIRCA prescription, up to a $800 monthly benefit.

    For: private insurance · source
  • Free medicine program

    Free medication program for uninsured and underinsured patients who meet eligibility requirements.

    For: no insurance, underinsured · source
  • Insurance and case manager help

    United Therapeutics Cares helps with insurance review, benefits investigation, prior authorization steps and coordinating delivery with the specialty pharmacy.

    The official page does not say who qualifies. Ask the program. · source

Good to know: ADCIRCA is an Eli Lilly trademark; United Therapeutics runs patient support. Patients with Medicare, Medicaid, VA, TRICARE or other government coverage may not be eligible for some help. Not available to Massachusetts residents; restrictions apply in California and some other states. Programs cover brand ADCIRCA; generic tadalafil is available.

Checked on the drugmaker's official pages on September 24, 2026. Programs change; confirm with the program before you rely on it.
Charity funds for Pulmonary Arterial Hypertension
  • From a charity · HealthWell Foundation
    Pulmonary Hypertension (Medicare Access) fund
    Open

    Pays for: Copays, premiums or other treatment costs. Medicare patients only.

  • From a charity · TotalAssist (formerly PAN Foundation)
    Pulmonary Hypertension fund
    Open

    Pays for: Out-of-pocket costs for approved medications, up to $9,500 per year. Requires health insurance (any kind).

  • From a charity · The Assistance Fund
    Pulmonary Hypertension fund
    Waitlist

    Pays for: Copays, coinsurance, deductibles and other health-related expenses.

    The foundation says: “WAITLIST — Accepting Waitlist Patients. TAF is currently accepting requests to join the enrollment waitlist for this program. Waitlists a…”
Status as each foundation showed it on September 28, 2026.

More ways to get help paying for treatment →

Clinical trial results

The PHIRST trial showed significant improvement in 6-minute walk distance with 40 mg tadalafil versus placebo. Also demonstrated improvement in time to clinical worsening and hemodynamic measures.

Development history

Tadalafil was originally approved as Cialis for erectile dysfunction (2003). The PAH indication was approved in May 2009 as Adcirca. Generic versions became available in 2018.

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Common questions about Tadalafil

▸What is Tadalafil (Adcirca)?

A once-daily PDE5 inhibitor for PAH that offers dosing convenience over sildenafil (which requires 3 times daily dosing). The same active ingredient as Cialis, marketed as Adcirca for PAH.

▸How does Tadalafil work?

Like sildenafil, tadalafil blocks PDE5 to prevent the breakdown of cGMP, allowing pulmonary blood vessels to stay relaxed and dilated. Tadalafil has a longer half-life (about 35 hours in people with pulmonary hypertension versus about 4 hours for sildenafil), which allows once-daily dosing and provides more consistent blood vessel relaxation throughout the day and night.

▸What are the side effects of Tadalafil?

Common side effects include headache, muscle aches, flushing, nasal congestion, indigestion, and back pain. Must not be combined with nitrates or riociguat. Hearing and vision changes should be reported immediately. Low blood pressure can occur. The label also warns against taking it with Cialis or other PDE5 inhibitors, says it is not recommended for people with pulmonary veno-occlusive disease, and advises getting emergency care for an erection that lasts more than 4 hours.

▸How is Tadalafil taken?

Taken by mouth as 40 mg (two 20 mg tablets) once daily, with or without food. The dose should not be split across the day. The once-daily dosing is an advantage over sildenafil's 3 times daily schedule. Generic versions are available.

▸Is Tadalafil FDA approved?

Yes, Tadalafil (Adcirca) is FDA approved (2009) for the treatment of Pulmonary Arterial Hypertension.

▸What is the advantage of tadalafil over sildenafil for PAH?

The main advantage is once-daily dosing. Tadalafil has a half-life of about 15 hours in healthy people and about 35 hours in people with pulmonary hypertension, compared to about 4 hours for sildenafil, so one daily dose of 40 mg (two 20 mg tablets) covers the whole day. This simplifies the medication schedule and may improve adherence. Both drugs have similar efficacy for PAH, so the choice often comes down to dosing convenience and insurance coverage.

▸Is Adcirca the same as Cialis?

Yes, both contain tadalafil. Cialis (2.5-20 mg) is prescribed for erectile dysfunction and benign prostatic hyperplasia, while Adcirca comes as 20 mg tablets and is taken as 40 mg (2 tablets) once daily for PAH. Generic tadalafil is available for both indications. For PAH, the 40 mg dose is taken once daily, which is higher than the typical erectile dysfunction dose.

▸Can tadalafil be combined with other PAH drugs?

Yes. Tadalafil is commonly combined with endothelin receptor antagonists as part of standard combination therapy. The AMBITION trial demonstrated the benefit of initial combination therapy with ambrisentan plus tadalafil. Tadalafil can also be combined with prostacyclins. However, it must not be used with riociguat (Adempas) due to the risk of severe hypotension from additive cGMP elevation.

▸Is generic tadalafil available for PAH?

Yes. Generic tadalafil for PAH became available in 2018, significantly reducing costs. Multiple manufacturers produce generic 20 mg tablets (patients take 2 tablets for the 40 mg PAH dose). Generic availability, combined with once-daily dosing, makes tadalafil one of the most practical and affordable PAH treatment options.

▸What did the PHIRST trial show?

The PHIRST Phase 3 trial demonstrated that tadalafil 40 mg significantly improved 6-minute walk distance (33-meter improvement versus placebo), reduced time to clinical worsening, and improved hemodynamic measures compared to placebo. The benefit was consistent across subgroups, including patients already taking background bosentan therapy.

This page is for informational purposes only and does not constitute medical advice. Drug information is sourced from public databases and peer-reviewed literature and may not reflect the most recent updates. Always discuss treatment options with your healthcare provider. Last reviewed: September 2026.

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