Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.
Patanol (Alcon Laboratories)
1 mg/mL eye drops in 5 mL dispensers
Approved indication: seasonal allergic conjunctivitis
Australian Medicines Handbook section 11.3.2
Topical antihistamines are useful in the treatment of allergic conjunctivitis, but until recently levocabastine has been the only single drug available in Australia. Prescribers now have the option of using olopatadine, an H1 receptor antagonist which also inhibits the release of histamine from mast cells.
Patients instil one or two drops of olopatadine twice a day. Very little of the drug enters the circulation and the quantity that is absorbed is largely eliminated unchanged in the urine.
Olopatadine has been compared with other treatments for allergic conjunctivitis, but many of these alternatives are not available as ophthalmic formulations in Australia. In studies lasting a few weeks olopatadine has compared favourably with drops of azelastine, nedocromil, ketotifen and ketorolac. Some studies have found that patients get more relief with loratadine and olopatadine than with loratadine tablets alone. Olopatadine may help patients whose main complaint is itchy eyes.
Adverse reactions to olopatadine drops include dry eyes, blurred vision, burning and stinging. Some patients may complain of altered taste.
To determine the role of olopatadine in Australian practice will require comparative studies with levocabastine, although the drugs may compete on price. If olopatadine is prescribed, treatment should not exceed 14 weeks.