More than 600 over-the-counter (OTC) drugs now use ingredients and dosages that 20 years ago were available only by prescription. The increasing availability of OTC drugs allows consumers to self-medicate and treat various symptoms. Yet a recent study of OTC phenazopyridine, a drug that relieves urinary tract pain and irritation caused by urinary tract infections, suggests that better patient education and post-OTC marketing surveillance are needed to ensure proper use of OTC medications. This is particularly important as popular prescription drugs, such as statins, head toward the OTC market, cautions Chih-Wen Shi, M.D., M.S.H.S., of the University of California, Los Angeles.
In the study, which was supported in part by the Agency for Healthcare Research and Quality (F32 HS11507), Dr Shi and colleagues surveyed a random sample of 434 purchasers of OTC phenazopyridine (predominantly well-educated white women) in 31 Los Angeles retail pharmacies. Phenazopyridine (Pyridium) is supposed to relieve pain, burning, and irritation due to urinary tract infections while the patient is awaiting medical evaluation and treatment, most likely with an antibiotic for the underlying infection. The survey asked what respondents thought was causing their symptoms and for what phenazopyridine would be effective.
Based on survey responses, the complex chain of self- diagnosis, treatment, and monitoring needed for effective OTC use of the drug rests upon a shaky foundation. For example, although OTC phenazopyridine has been popularly advertised in the media as an interim pain reliever pending a medical appointment for a urinary tract infection, only 29 percent correctly characterized the likely cause of their symptoms as an infection, and only 57 percent correctly characterized the action of the drug (pain relief).
Details are in "Consumer knowledge of over-the-counter phenazopyridine," by Dr. Shi, Steven M. Asch, M.D., M.P.H., Eve Fielder, Dr.P.H., and others, in the May 2004 Annals of Family Medicine 2(3), pp. 240-244.