Discontinuation of the herbal preparation Hypericum perforatum, also known as St John's wort, associated with improved intraocular pressure control in a patient on topical beta-blockers for primary open-angle glaucoma

[2] It is known to interact with a number of drugs, including beta-blockers, as it induces the hepatic cytochrome P450 system and causes faster drug metabolism. [3] There is limited information on the activity of these enzymes in the eye, but the studies have confirmed cytochrome P450-dependent monooxygenase activity in the ciliary body and retinal pigment epithelium of bovine eyes. The sudden decrease in IOP and long-term maintenance of pressures in target range after discontinuation of St. John's wort could indicate that the patient was previously experiencing a diminished effect of topical beta-blockers.