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.
Iopidine (Alcon Laboratories)
0.5% ophthalmic solution
Several drugs are available to reduce aqueous secretion or increase aqueous outflow (see 'The medical treatment of glaucoma' Aust Prescr 1993;16:34-7). Apraclonidine can be used to control the intraocular pressure of patients on maximally tolerated treatment for chronic glaucoma.
The drug is an alpha adrenergic agonist. Intraocular pressure falls with in an hour of a single dose and the peak reduction occurs in 3-5 hours. The half life is 8 hours and 3 times a day instillation is recommended. A 5minute interval should separate the instillation of apraclonidine and other eye drops.
After two months' treatment, the effectiveness of apraclonidine may decline. If treatment is continued for more than 3 months, patients should be more closely monitored, particularly for corneal changes.
In clinical studies, 15% of patients discontinued treatment due to adverse effects. The patients' complaints included hyperaemia, pruritis, discomfort and dry mouth. Systemic adverse reactions include headache, asthenia and chest pain. The drug is contraindicated in patients taking monoamine oxidase inhibitors, tricyclic antidepressants or sympathomimetics.