PURPOSE: To compare the cardiovascular and mydriatic effects of 2.5% and 10.0% phenylephrine. METHODS: A case-control, randomized, crossover clinical trial study. We monitored heart rate (HR), blood pressure (BP) and mydriasis in healthy volunteers aged 18-45 years after the instillation of 2.5% and 10.0% phenylephrine in two different occasions. RESULTS: The sample comprised 28 healthy volunteers, 17 male and 11 female, with a mean age of 26.5 years. No changes in heart rate and systolic blood pressure were observed. No significant variation of the mean diastolic blood pressure was found after 1, 5, 10 and 30- minute instillation of 2.5% phenylephrine. However, with 10.0% phenylephrine, there was an increase in mean diastolic blood pressure after five and ten minutes, followed by a drop after 30 minutes, which was not statistically significant. Mydriasis was more marked in both eyes with a statistically significant difference after instillation of 10.0% phenylephrine. CONCLUSIONS: The mydriatic effect was greater with 10.0% phenylephrine than with 2.5% phenylephrine and the difference was statistically significant. No statistically significant difference was found in relation to cardiovascular effects in both phenylephrine concentrations.
Phenylephrine; Heart rate; Blood pressure; Mydriatics; Cardiovascular system; Ophthalmic solutions; Ophthalmology
