Adcirca (tadalafil)

Adcirca (tadalafil) is a once-daily tablet for pulmonary arterial hypertension (PAH), which is high blood pressure in the arteries of the lungs^[1]. The FDA approved Adcirca on May 22, 2009, to treat PAH (WHO Group 1) and improve exercise ability^[2][1]. The FDA has approved generic tadalafil 20mg tablets rated as equivalent to Adcirca^[9]. In the 16-week PHIRST trial of 405 people, tadalafil 40mg increased 6-minute walk distance by 33 meters more than placebo^[1]. The Adcirca label says it must not be used with nitrate medicines or with riociguat (Adempas), because together they can lower blood pressure too much^[1].

In PAH, the lining of the lung arteries releases less nitric oxide, so the artery walls get less of a relaxing signal called cGMP^[1]. Tadalafil blocks PDE5, the main enzyme that breaks down cGMP in the blood vessels of the lungs^[1]. With more cGMP available, the muscle in the lung artery walls relaxes and the vessels widen^[1]. Tadalafil stays in the body a long time, with an average half-life of about 35 hours in people with pulmonary hypertension not taking bosentan and about 15 hours in healthy people^[1].

Adcirca does not carry a boxed warning, and headache was its most common side effect^[1]. In the main trial, headache was reported by 42% of people on 40mg versus 15% on placebo^[1]. Muscle aches (14% vs 4%) and flushing (13% vs 2%) were also more common with Adcirca 40mg than with placebo^[1]. Pain in the arms or legs (11% vs 2%) and indigestion (10% vs 2%) were reported more often as well^[1]. Nasal or sinus congestion affected 9% of people on 40mg versus 1% on placebo^[1]. The label lists nitrate medicines as a contraindication and says nitrates should not be used within 48 hours of the last Adcirca dose^[1]. The label also lists guanylate cyclase stimulators such as riociguat (Adempas) as a contraindication^[1]. The label warns about drops in blood pressure and says Adcirca is not recommended for people with pulmonary veno-occlusive disease (PVOD)^[1]. Sudden vision loss can be a sign of NAION, a type of optic nerve damage that may be permanent^[1]. Sudden decrease or loss of hearing has been reported in people taking tadalafil, though the label says it cannot be determined whether the drug caused it^[1]. The label advises against taking Adcirca together with Cialis or any other PDE5 inhibitor^[1]. The label advises seeking emergency care for an erection lasting more than 4 hours^[1].

The usual dose is 40mg, taken as two 20mg tablets once a day with or without food^[1]. The label says the 40mg dose should not be split up over the course of the day^[1]. People with mild or moderate kidney problems start at 20mg once daily and may move up to 40mg if they tolerate it^[1]. The label says to avoid Adcirca in severe kidney disease (including people on dialysis) and in severe liver cirrhosis^[1]. For mild or moderate cirrhosis, the label suggests considering a starting dose of 20mg once daily^[1]. For people taking the HIV medicine ritonavir, the label sets special timing and a 20mg once-daily starting dose^[1]. Safety and effectiveness of Adcirca in children have not been established^[1]. The FDA has approved generic tadalafil 20mg tablets rated as equivalent to Adcirca^[9].

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

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