Cosopt has been approved for the reduction of elevated intraocular pressure in patients with open-angle glaucoma or ocular hypertension who do not respond adequately to beta-blockers alone. Both components of Cosopt are leading therapies in their product categories and are currently available from Merck as individual medicines under the brand names Trusopt and Timoptic.

In clinical studies, Cosopt administered twice a day produced reduction in intraocular pressure greater than that seen when either Trusopt or Timoptic was used as sole therapy. The reduction was slightly less than that seen when both were used individually in a concomitant daily treatment regimen of Trusopt three times daily and Timoptic twice daily.