Maximising glaucoma treatment outcomes
Fixed combinations of IOP-lowering medications provide several advantages in clinical practice over unfixed combinations.
Gábor Holló MD
Fixed combinations of IOP-lowering medications provide several advantages in clinical practice over unfixed combinations, and the benefits outweigh their limitations, said Gábor Holló MD, PhD, at Glaucoma Day 2016 held during the XXXIV Congress of the ESCRS in Copenhagen, Denmark.
“Approximately half of patients with open-angle glaucoma need more than one medication to reach target IOP. When it is certain that one medication is not enough, we should not wait for long before moving to a fixed combination,” said Dr Holló, Professor of Ophthalmology, Semmelweis University, Budapest, Hungary.
There is increasing evidence that a fixed combination IOP-lowering medication supports quality of life and adherence in the long-run. Nevertheless, individual decision-making is essential. Although a fixed combination may be optimal overall, it does not mean that it is good for everybody, he cautioned.
Better efficacy is one likely benefit of using a fixed combination versus two separate IOP-lowering drugs. The fixed combination simplifies the treatment regimen, which should improve treatment adherence and persistence, and it avoids medication washout from a too short inter-drop instillation interval, explained Dr Holló.
Ocular tolerance may also be better with a fixed combination because it can reduce preservative exposure. In addition, timolol, which is found in most fixed combinations, often improves the local tolerability of the second ingredient.
Nevertheless, side effects do occur and physicians should know the active ingredients in the fixed combination drops they prescribe so that they can try to determine the responsible molecule when a patient experiences an adverse reaction.
Approximately half of patients with open-angle glaucoma need more than one medication to reach target IOP.
“Some doctors only know the commercial brand name of the fixed combination. If they cannot make an educated guess about a causal relationship with one of its ingredients, it will be necessary to stop the fixed combination and restart therapy, building it up in a stepwise manner,” he said.
Cost may also be lower with a fixed combination product. Dr Holló said the limitations of fixed combination drops are minor compared with the benefits. Although IOP reduction in controlled comparative trials was greater using two drugs as an unfixed combination than as a fixed combination, the difference was minimal, and not clinically significant.
Another downside of fixed combinations is that they limit dosing flexibility. Dr Holló suggested, however, this issue is only rarely important.
“Special attention may be required for a patient who needs smoothing of a funny IOP spike during the day, and in that situation we cannot use the fixed combination,” he explained.