One of the other important aspects of OTC switches is the actual-use study, where the compound, although it has been very well studied, is put in various public domains, such as pharmacies or malls. Patients are asked to come back after a 2-week time frame and asked if they used the drug appropriately and, if not, why not?
Overactive bladder is a tricky condition. You can get urgency and frequency associated with urinary tract infection. You can get urgency and frequency associated with dietary ingestion of some liquids and food stuffs in some patients. There probably was some blunting of effect because of dispersal in the general population.
When I look at other available OTC products that are used by patients with overactive bladder, the best are the azo-based products, such as Azo-Gantrisin. Patients take those frequently for urgency/frequency and obviously they have a urinary tract suppression indication, not urgency/frequency.
When I worked at the FDA in 1999, terazosin was considered for an OTC switch for outlet obstruction and it went nowhere. What about the more selective alpha-blockers that are off patent now?
The concern with alpha-blockers is the potential for either postural blood pressure changes and/or hypotensive effects, which are very limited but still in the label, even of the very selective alpha-blockers. Another concern in the general population that may not have been as adequately screened as clinical trial populations relates to patients with more marginal cardiac or vascular status. If one of these drugs enters the OTC world, there is a risk of exacerbation of syncopal episodes and other concerns associated with it, even though these agents are super selective.
Tamsulosin is probably the closest of these agents to being considered for OTC status. Again, however, from our clinical results with tamsulosin, we know that some patients may have postural hypotension or at least near-syncopal episodes that may or may not be due to hypotension. Ejaculatory dysfunction is also a concern, but is less of a threat.
Are 5-alpha-reductase inhibitors good candidates for OTC?
The overall side effects are relatively low with 5-alpha-reductase inhibitors. Obviously, the more prominent ones are the sexual side effects. There are some issues with fluid retention associated with them. Also, they’re not the most pleasant drugs to take. The potential for onset of gynecomastia associated with them can be very embarrassing. Although those effects are not life or limb threatening, they are not exactly things that people are happy to encounter.