A study published in the Indian Journal of Pharmacology showed that alfuzosin, tamsulosin, and silodosin, three of the most widely used drugs for the treatment of benign prostatic hyperplasia (BPH) and associated lower urinary tract symptoms (LUTS), have comparable efficacies.
While the study also revealed that all three drugs were well-tolerated, the authors reported that tamsulosin caused cardiac side effects in some instances, increasing the time it takes for heart muscles to contact and then recover (QTc). This was already known to be the case for alfusosin, and researchers noted that these two drugs must be used with great caution in people who have a history of heart problems, with silodosin being relatively safer in such cases.
Alfuzosin, tamsulosin, and silodosin are known as alpha blockers, drugs that bind to receptors found on the surface of certain cell types. They work by relaxing the muscles around the prostate and bladder to make it easier to pass urine.
“The occurrence of QTc prolongation in three subjects with tamsulosin in the present study is an unexpected adverse event as there are no reports of QTc prolongation with tamsulosin in any of the previous studies,” the researchers wrote in their study, titled “A randomized, comparative, open-label study of efficacy and tolerability of alfuzosin, tamsulosin and silodosin in benign prostatic hyperplasia.”
The study involved 90 men with BPH and LUTS, 45 years of age and older. Participants were randomly divided into three groups of 30, and were given either alfuzosin, tamsulosin, or silodosin for a period of 12 weeks. The treatment response was monitored at two, four, eight, and 12 weeks.
Outcome measures were the International Prostate Symptom Score (IPSS) assessing issues such as how often, at what intervals, and how urgently people needed to pass urine. The study also looked at the Quality of Life Score (QLS), assessing how individuals with BPH feel about their condition. Both parameters significantly and progressively improved following drug intake. The maximum improvement was observed at two weeks and continued throughout the study, and there were no differences in improvements noted among the three drugs.
“The good tolerability and high level of compliance to the study medications are indicators for good patient acceptability. The lack of QTc prolongation with silodosin is of a particular advantage while using in elderly patients with pre-existing cardiac disease and risk of arrhythmia, but the higher cost of silodosin would be a limiting factor for long-term usage,” the researchers concluded, adding, “Further, elaborate multi-centric studies (…) may be undertaken to generate more data regarding the relative efficacy and tolerability of these medications and also to detect very rare or unusual adverse effects.”