Page 44 - 21st Century Perspective - Glaucoma Supplement

Combination Drugs

The two salient virtues in using combination drugs are simplicity of dosing schedule and reduced
ocular surface exposure to preservatives.

A quick note regarding potential ocular surface toxicity from preservatives (most notably BAK): If a
patient has concurrent dry eye disease and glaucoma, thoughtful consideration should be given to
reducing such exposure. Preservative-free glaucoma medicines and preservative-free artificial tears
are available. The problem with all these preservative-free eye drops is that they are more expensive

than their preserved counterparts; thus, we again are faced with the challenge of balancing cost,
efficacy and safety.

Only three preservative-free glaucoma medicines are available:

● timolol;
● tafluprost; and
● a combination of generic dorzolamide and timolol (Cosopt, Akorn). Cosopt is also available in
a standard preserved bottle.

Quite a few preservative-free artificial tears are available. Our favorite is Ocusoft’s Retaine MGD,
which is a lipid-based formulation. When both a glaucoma drop and an artificial tear are needed,
perhaps the most practical approach is to use the glaucoma drop of your choice with a
preservative-free artificial tear. Before we get into the details regarding the three combination
glaucoma drugs, let us give a thoughtful overview: First, these combination drugs contain two
inexpensive generic drugs that, when combined, become an expensive, brand name-protected

medicine. (Note that brinzolamide and dorzolamide share common efficacy, so one could easily be
substituted for the other.) Most importantly, it is critical that each component drug is known to be
effective for the patient before logical thought would allow them to be used together. This is basic
common sense, and the efficacy of each ingredient medication can easily be determined via a
monocular therapeutic trial.

Furthermore, these less expensive generic ingredient drugs alone may achieve target pressure;
thus, prescribing an individual drug would represent a substantial cost-saving to the patient. Simply

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