A brief report in the American Journal of Ophthalmology caught my attention as I was writing this column.[Rowe, 1997 #11294] The authors describe single cases of ocular hypotony with choroidal effusion, recurrent cystoid macular edema, and facial rash in patients taking latanoprost. Hypertrichosis and increased pigmentation of eyelashes have recently been reported.[Johnstone, 1997 #11295][Wand, 1997 #11186] We have seen pseudophakic patients who developed uveitis after taking latanoprost and reports of uveitis and cystoid macular edema have been surfacing on the Internet. Are these real side effects or are they coincidental? Are they due to drug interactions? Can you prove a side effect is a side effect without retesting. How can we connect rare or idiosyncratic side effects with a drug?

The National Registry of Drug-Induced Ocular Side effects is a repository of such reports and is a valuable source of information not only for the clinician wishing to verify whether an unusual side effect has been noted by others, but as a source for data collection in the case of serious or unusual side effects. If not for the National Registry, our awareness of the association between aplastic anemia and carbonic anhydrase inhibitors might have taken much longer to surface.[Fraunfelder, 1985 #7301] Numerous reports of side effects of antiglaucoma and other drugs have been possible only ophthalmologists reported them to the Registry.[Van Buskirk, 1980 #7013][Van Buskirk, 1984 #11296][Fraunfelder, 1994 #11298; Fraunfelder, 1995 #11297][Macarol, 1994 #11299][Alder, 1995 #11300] Ophthalmologists are urged to use this service and to report unusual side effects.

Who is probably the leading authority on the ocular side effects of chloroquine and hydroxychloroquine? - Mike Easterbrook, M.D., Toronto, Canada; Who is probably the leading authority on tamoxifen? - Mike Gorin, M.D., Pittsburgh, PA; Who is probably the leading authority on the side effects on a recently released ocular medication? - We like to think it’s the National Registry of Drug-Induced Ocular Side Effects.

With a new drug, spontaneous reporting systems may have insights into possible adverse effects before other sources. In a specialized area of medicine, such as ophthalmology, one may not see the volume of patients necessary to draw a correlation between a particular drug and its side effects. A national registry to correlate suspicions from a large volume of ophthalmologists may provide early clues as to a possible association. If a number of these “possible” associations are found with a particular drug, especially if they form a pattern, then more definitive studies can be undertaken. Unfortunately, these definitive studies are seldom done due to lack of funding.

The National Registry, established in 1975, was an attempt to act as a clearing house for suspected adverse reactions of drugs used by ophthalmologists. In some cases, this “pooled” data might allow us to more rapidly recognize these events. The objectives of the Registry are:

To make available this data to physicians who feel they have noted a

possible drug-induced ocular side effect.

Ophthalmologists are encouraged to send us suspected drug-related adverse events if associated with a new drug, or rare or unusual events with established drugs. If a trend is identified, you will be put in contact with others (your name not released without your permission) for possible publication. We are not adverse to helping clinicians with legal questions, since 25% to 35% of physicians’ medicolegal problems may be related to side effects of drugs. We also field questions for clinicians with questions on possible drug-related side effects in their patients. This latter service is funded, in part, by the American Academy of Ophthalmology.

Latanoprost is an excellent drug, and the above reactions are, in the main, reversible. Cystoid macular edema, while not proven to be caused by latanoprost, certainly is suspect. Thus far, possible latanoprost associated CME has been reversible when the drug was stopped. In rare instances, latanoprost may cause uveitis. Some feel the drug may reactivate patients who previously have had uveitis. This has not been proven, but the drug is suspect. Iris pigment proliferation, while not a major concern as far as malignancy, is more of a concern on long-term therapy as to the potential for inducing pigmentary glaucoma. Only long-term studies will answer this question.

To our knowledge, brominidine tartrate 0.2%, a new selective alpha-adrenergic antagonist, has minimal cardiovascular side effects. Even so, it should be used with caution in patients with severe cardiovascular disease, cerebral or coronary insufficiency, peripheral vascular insufficiencies, or orthostatic hypotension. Patients complain of dry mouth, ocular injection and ocular burning or stinging. Allergic reactions may occur in up to 10% of patients. One major side effect appears to be drowsiness. Possible interactions with monoamine oxidase inhibitors and tricyclic antidepressants, however, is another. Only with the help of the broader community of ophthalmologists, submitting detailed reports, with retesting when possible, will our rapid awareness of these and other side effects be possible.

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