[Is it possible to combine fixed therapeutic associations?]

The number of fixed associations to treat intraocular pressure has increased over the recent years, to improve patient's treatment adherence. They are generally considered as comparable to the same components administered separately with, in some cases, less side effects. It could thus be appealing to combine fixed associations to reduce these side effects and retain efficacy. However, almost all fixed associations contain timolol, a beta blocker, with a risk of an excessive beta blocking dose and related systemic adverse drug reactions. Several fixed-associations contain a prostaglandin analogue. Their combination would not have a superior efficacy to one fixed combination taken alone. Furthermore, an increased risk or incidence of adverse drug reactions would appear. Specific clinical studies are required before recommending their use in daily clinical practice.