Medications combined in a single bottle have the potential benefits of improved convenience and patient adherence. Fixed combinations consisting of timolol and another agent—a CAI (dorzolamide or brinzolamide), an α2-adrenergic agonist (brimonidine), or a prostaglandin analogue (latanoprost, travoprost, or bimatoprost)—are available in many countries (see Table 12-2). In addition, fixed combinations of (1) brimonidine and brinzolamide and (2) latanoprost and netarsudil are available.
In general, the efficacy of fixed-combination formulations is similar to that of each of the components instilled separately. In the case of fixed-combination agents that include timolol and are administered twice daily, the total amount of the β-blocker may actually be more than necessary, because nearly the full effect of a β-blocker can be achieved with once-daily dosing. The ocular adverse effects are the same as for both drugs given individually. In general, except in the setting of an acutely elevated or dangerously high IOP, the clinician should make sure each component of the fixed combination is effective in further lowering the IOP by adding the individual components sequentially.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.