To the Editor.
—I would like to accent some of the topics that Ball and Schneider1 address in their article, adding a different emphasis. To accurately compare the cost of items, one must insure that all are equal. The β-blockers discussed in this article are not equivalent with respect to pharmacology, efficacy, safety, or comfort.The pharmacology of betaxolol hydrochloride is different than those of the other compounds. Betaxolol is a cardioselective β-adrenoceptor antagonist. The others are nonselective. The article, due to timing, does not include carteolol hydrochloride. Carteolol is a β1-β2 adrenoceptor antagonist with intrinsic sympathomimetic activity. Carteolol's pharmacokinetics differ, at least after systemic administration.The data analysis assumes a "roughly equivalent ocular hypotensive effect." The ocular hypotensive effect of β1-blockers is not equivalent to those of nonspecific β-blockers, either as an initial therapy or when switching from a nonspecific β-blocker to a
Robin AL. Pitfalls in Comparing the Costs of Various β-Adrenoreceptor Antagonists. Arch Ophthalmol. 1993;111(3):299. doi:10.1001/archopht.1993.01090030017007