Last year we reported about a poorly conducted study regarding the side effects of Propecia. The same researchers have now published a follow up study, where the interpretation of the results remains questionable.
The study reassessed 54 individuals with a mean age of 31 years that did not present with any other medical conditions. The patients were sent a follow up questionnaire called ASEX via email. In total 81% responded and of those 89% met the definition for sexual dysfunction. The length of use of the medication, as well as duration of the side effects appeared to be unrelated. However, the majority of individuals in the study had experienced the side effects for 1-2 years. Based on this, the authors concluded that there is a possibility for the side effects to be long lasting or potentially permanent and therefore urged for caution when prescribing Propecia.
To a large extent, the recruitment of participants depended on the same sample they used in the previous study. Yet, this was one of the main flaws of the initial study. By recruiting participants that already exhibited sexual side effects, the authors made it challenging to generalise the findings to all individuals who take Propecia. Although they specified that their sample did not take any other medications or have any other conditions that may have affected the outcome, there was no mention of corroborating this with medical records.
Although we understand the need to research side effects of any medication, we also feel that it is important that more rigorous studies are made before suggesting that the side effects may be permanent. We also agree that caution should be taken when prescribing any medication and as such fail to see the value of the conclusion of this badly constructed study.