The content of this evidence summary was up-to-date in May 2013. See summaries of product characteristics (SPCs), British national formulary (BNF) or the MHRA or NICE websites for up-to-date information.
Tadalafil is a reversible phosphodiesterase type 5 inhibitor available as an oral tablet in various strengths. In October 2012, the 5 mg tadalafil tablet (taken once daily) was granted marketing authorisation to treat signs and symptoms of benign prostatic hyperplasia in adult men. Other strength tablets (2.5 mg, 5 mg, 10 mg and 20 mg) already have marketing authorisation to treat erectile dysfunction in adult men.
The main drug treatments currently recommended in the NICE pathway on lower urinary tract symptoms in men are alpha blockers and 5-alpha reductase inhibitors. Tadalafil (5 mg only) represents an additional treatment option and is the only drug in its class licensed for treating signs and symptoms of benign prostatic hyperplasia. Assessing tadalafil's likely place in therapy in relation to current drug treatment is difficult because there are few published randomised trials of its use in first-line, second-line or combination treatment compared with current best practice.
This evidence summary is based on 2 studies of tadalafil that have been published in full. The first (Roehrborn et al. 2008) was a large (1058 men), double-blind, placebo-controlled, dose-finding randomised controlled trial (RCT) comparing various strengths of tadalafil monotherapy once daily with placebo for 12 weeks (212 men were assigned the tadalafil 5 mg dose). After the 12-week study ended, 427 men elected to take part in a second, 1-year, open-label extension study (Donatucci et al. 2011) that used tadalafil 5 mg daily monotherapy. This 5 mg dose was used regardless of initial treatment in the 12-week study.
Tadalafil 5 mg daily improved lower urinary tract symptoms compared with placebo after 12 weeks of treatment (an average [mean] 2.6 point additional improvement in overall International Prostate Symptoms Score [I-PSS]) compared with placebo. While this difference was statistically significant, a clinically meaningful improvement in score is defined in the study as a 3-point improvement in I−PSS from baseline. Other statistically significant improvements over placebo were seen for I-PSS obstructive subscore, I-PSS irritative subscore and I-PSS quality of life. Most of the primary benefits associated with tadalafil occurred within the first 12 weeks of treatment and were maintained or improved to a much smaller degree for up to 1 year.
During the 1-year open-label extension study, 4.7% of men receiving tadalafil 5 mg daily reported severe adverse events, 5.2% reported adverse events leading to discontinuation, and 57.6% reported 1 or more treatment-emergent adverse events of any severity.
A 28-tablet pack of tadalafil 5 mg costs £54.99; this represents the approximate monthly cost of the drug treatment.
When making decisions about the use of tadalafil, localities will need to take this evidence of marginal clinical effectiveness into account alongside the one year data on tolerability. The acquisition cost of tadalafil is also higher than other treatment options. The prescribing of tadalafil for erectile dysfunction in England is subject to statutory prescribing restrictions through Schedule 2 of the NHS (general medical services contracts) (prescription of drugs etc.) regulations 2004 and the NHS (Pharmaceutical and Local Pharmaceutical Services) Regulations 2013. These prescribing restrictions do not apply to tadalafil when it is prescribed in primary care on the NHS for benign prostatic hyperplasia (Department of Health: personal communication October 2013).
Roehrborn CG, McVary KT, Elion-Mboussa A et al. (2008) Tadalafil administered once daily for lower urinary tract symptoms secondary to benign prostatic hyperplasia: a dose finding study. The Journal of Urology 180: 1228–34
Donatucci CF, Brock GB, Goldfischer ER et al. (2011) Tadalafil administered once daily for lower urinary tract symptoms secondary to benign prostatic hyperplasia: a 1-year, open-label extension study. British Journal of Urology International 107: 1110–6
'Evidence summaries: new medicines' provide summaries of key evidence for selected new medicines, or for existing medicines with new indications or formulations, that are considered to be of significance to the NHS. The strengths and weaknesses of the relevant evidence are critically reviewed within this summary to provide useful information for those working on the managed entry of new medicines for the NHS, but this summary is not NICE guidance.