Patients taking oral drugs for the first time to treat their osteoporosis have been shown to be at increased risk of developing scleritis or uveitis.
A study published online this week in the Canadian Medical Association Journal looked at the incidence of the diseases among users and non-users of oral biphosphonates, a class of drug commonly used to treat osteoporosis by reducing loss of bone mass.
The risk of scleritis was found to be 63 per 10,000 for first time users of the drug as compared with 36 out 10,000 non-users. The increased risk for uveitis was significant but less strong, at 29 per 10,000 as compared with 20 out of 10,000 non-drug users. Over 10,000 first time biphosphonate users and more than 900,000 non-drug users were analysed.
Lead author Mahyar Etminan of the University of British Columbia said: 'This is the first study to quantify the risk of uveitis and scleritis with these drugs.'
There are many known potential adverse responses with biphosphonates, but the researchers pointed out that the link with scleritis was less well known and practitioners dealing with osteoporosis patients should be more aware of the connection. The ocular effects appeared reversible on cessation of the drug and practitioners would be wise to refer to the prescribing doctor were such an adverse effect be suspected.