The effect of topical 2.5% phenylephrine and 1% tropicamide on systemic blood pressure and pulse

A prospective double-blind trial is described in which patients were given either 1% tropicamide, 2.5% phenylephrine, a combination of the two drugs, or a placebo. Blood pressure measurements and pulse rates were determined at 5, 10 and 15 minute intervals post-instillation. No significant change in systolic or diastolic blood pressures were determined for any of the treatment groups at any of the time intervals; however, a slight but significant decrease in pulse rate was noted in some of the treatment groups. The data are analyzed according to other variables. Factors which may have influenced the findings are discussed.