攝護腺肥大和勃起功能障礙常常同時困擾著熟齡男性。長效型第五型磷酸水解酶抑制劑Tadalafil和5α還原酶抑制劑Finasteride都是攝護腺肥大治療用藥，長效型第五型磷酸水解酶抑制劑Tadalafil可放鬆攝護腺和陰莖海綿體的平滑肌，使排尿順暢並改善勃起硬度，5α還原酶抑制劑Finasteride則是藉由減少男性賀爾蒙作用來縮小攝護腺。

2021年12月，美國藥物管理局核准攝護腺治療新藥Entadfi，此藥合併長效型第五型磷酸水解酶抑制劑Tadalafil和5α還原酶抑制劑Finasteride。單獨使用Finasteride治療攝護腺肥大患者時，部分患者會有性欲降低或勃起功能障礙的現象，如同時使用能改善勃起功能的Tadalafil和縮小攝護腺的Finasteride則可能能避免此困擾。

此合併治療對於性活躍且同時有攝護腺肥大問題的年輕族群很想吸引力，然而相關研究顯示Finasteride可能在部分患者身上造成性功能(射精或勃起)障礙和憂鬱的現象。因此Entadfi這個複方藥物的療效、副作用和經濟效益仍需要更大規模的研究去驗證。

Abstract
Co-administration of finasteride and tadalafil has been suggested specifically for 5α-reductase inhibitor responders with erectile dysfunction. Tadalafil, in addition to improving the short-term efficacy of finasteride therapy, also mitigates erectile dysfunction, which is one of the sexual side effects commonly reported with finasteride use. In other words, combination therapy with finasteride and tadalafil embraces the prescribing cascade rather that avoiding it in this population . In traditional prescribing cascades, an adverse drug effect is misdiagnosed as a new medical condition and treated with a potentially unnecessary drug that may further cause additional, avoidable adverse drug effects. Considering the breadth of medical and abundant newer surgical options available to patients suffering from lower urinary tract symptoms secondary to an enlarged prostate due to BPH, men with baseline erectile dysfunction or those who develop it after finasteride use should discontinue finasteride use. This would avoid a prescribing cascade with tadalafil. Patients and providers should consider alternative treatment options for BPH and erectile dysfunction. Possible alternatives for patients who wish to preserve their sexual function include tadalafil monotherapy and surgical treatment with new minimally invasive surgical techniques that have better sexual outcomes. In addition, sexually active patients suffering from erectile dysfunction in any context should undergo a full work-up for their condition to ensure that sexual function is optimized.