dorzolamide and Thrombocytopenia

To report a severe case of dorzolamide-induced immune thrombocytopenia, to review the literature on this topic, and to draw attention to the serious potential side effects of this topical sulfonamide.. An 83-year-old man with primary open-angle glaucoma in both eyes who was taking topical dorzolamide therapy for 3.5 years developed a severe thrombocytopenia (10,000 platelets/microL). The amount of platelets was not influenced by prednisone therapy but increased rapidly to 100,000/microL after the withdrawal of dorzolamide.. Although the potential capacity of sulfonamides to induce thrombocytopenia is well known, no case of dorzolamide-induced immune thrombocytopenia was published in the medical literature until July 2000.. Considering the possible severe side effects that can be induced by topical dorzolamide 2%, ophthalmologists should carefully evaluate during the medical history of their patients the risk of sensitivity to sulfonamides.

Topics: Aged; Aged, 80 and over; Carbonic Anhydrase Inhibitors; Glaucoma, Open-Angle; Humans; Male; Platelet Count; Sulfonamides; Thiophenes; Thrombocytopenia

Antibiotic and non-antibiotic sulphonamides are often prescribed. Although chemical differences make cross-reactivity rare, reactions may be severe in patients allergic to sulphur. Adverse reactions are common with sulphonamides but low platelets and skin changes are rarely associated with eye-drops for glaucoma. A woman treated with dorzolamide and timolol presented with disseminated eruption. On admission, her physical examination was unremarkable except for the skin changes and severe thrombocytopaenia was detected. Skin biopsy showed hyperkeratosis, acanthosis, perivascular and periadnexal infiltrates with no vasculitis. After discontinuation of eye-drops, the eruption improved but low platelets persisted. Skin changes reappeared with use of dapsone which suggested sulphonamide cross-reactivity.

Topics: Anti-Infective Agents; Antihypertensive Agents; Biopsy; Dapsone; Drug Eruptions; Female; Glaucoma; Humans; Liver Function Tests; Middle Aged; Ophthalmic Solutions; Platelet Count; Sulfonamides; Thiophenes; Thrombocytopenia; Timolol