Professor David Brown of the University of Portsmouth and colleagues simulated a customer search and evaluation of 184 retrieved Web sites, using evaluation tools focusing on quality and safe medicine use.
The results showed a potential purchaser of statins -- medication used to lower cholesterol -- is likely to encounter Web sites from a wide geographical base of generally poor quality.
The study, published in the journal Pharmacoepidemiology & Drug Safety, found general contraindications -- a reason to withhold a certain medical treatment -- were absent in 92.4 percent of sites and contraindicated medicines were absent in 47.3 percent. Key warnings were absent 37 percent of the time on the appearance of symptoms associated with myopathy -- in which muscle fibers do not function -- and 48 percent for liver disease, 91 percent for hypersensitivity and 96 percent for pancreatitis.
Most Web sites presented a chaotic and incomplete list of known side effects -- 7 percent presented a list compatible with current prescribing information and two-thirds attempted to describe any side effects in lay language.
"Web sites offering statins for sale contain little information on the safety of these drugs, which are intended as prescription only medicines" Brown said in a statement. "There is an inherent danger in patients seeking to self-medicate in this way without consulting a healthcare professional and being appraised of ways to use the medicine safely."