The impending availability of generic latanoprost is creating much discussion about the potential effect on the prescribing of IOP-lowering medications.
The recent introduction, however, of a reduced-concentration formulation of bimatoprost 0.01% (Lumigan 0.01%, Allergan) may be another reason why ophthalmologists should be thinking about altering their paradigm for ocular hypotensive therapy, said Donald R. Nixon, MD, director, TriMed Eye Center, Barrie, Ontario.
As an ophthalmologist practicing in Canada, he has had access to bimatoprost 0.01% for almost 1 year. Based on his experience and clinical trial evidence, Dr. Nixon believes bimatoprost 0.01% provides the best of both worlds for IOP-lowering treatment in terms of activity and safety/tolerability.
"I now have well over 300 patients [taking] bimatoprost 0.01% in my clinical practice," he added. "Based on its efficacy and tolerability, I am comfortable and confident [in] prescribing bimatoprost 0.01% for my treatment-naïve patients, and it has offered an excellent option as an alternative for maintaining a monotherapy regimen in latanoprost-treated patients who are candidates for a switch."
Making the switch
Three "Ws" are relevant to switching prostaglandin analogue therapy: when, why, and what. "When" refers to early therapy or established treatment, and there are different "why" scenarios for both of those groups. As a more overarching principle, the "why" could refer to the basic reason to switch instead of add, and that is to maintain monotherapy for as long as possible.
"For patients started on latanoprost, treatment modification may be considered if IOP control is thought to be insufficient, either after an initial trial or over time," Dr. Nixon said. "However, the goal in changing treatment is to keep it simple in order to optimize compliance."
He reviewed a number of clinical situations where switching existing latanoprost therapy would be considered and why bimatoprost represents the best "what" for the switch.
The first scenario is the patient who does not achieve adequate IOP-lowering when latanoprost is started as first-line therapy. Results from five published papers2-6 show such patients can benefit from switching to bimatoprost. For example, defining non-response as <10% reduction from baseline mean IOP, Gandolfi et al. showed in a prospective, randomized, crossover study that 87% of patients switched to bimatoprost 0.03% achieved treatment success. More impressive, two-thirds of patients maintained an IOP <18 mm Hg at all measurement points after switching to bimatoprost.