These studies provide evidence of compliance, even though they don't address the issue head on, said Dr. Schuman, professor of ophthalmology at Tufts and director of the glaucoma service at New England Eye Center in Boston. However, subjects in trials are thought to be more particular about how and when they put their drops in. And again, in the real world of private practice, when patients were taken off two bottles and put on one, their pressures went down. It's my opinion that combination drugs may help the clinician use adjunctive or multidrug regimens with greater compliance. And that translates to greater efficacy.
Combination products expose patients to less preservative.
Combination products can increase the efficiency of drug delivery by reducing the likelihood of washout, which can occur when a second drop is administered before the first drop is completely absorbed. Caveats to Consider Despite general enthusiasm for combination drugs, there are some caveats to heed. And Dr. Schuman warned that combination drugs should be prescribed only when patients need two or more drugs. If you can use a single drug to treat the patient, then use that. I wouldn't start with a combination drug.