Comparison of the cardiovascular effects of 2.5% phenylephrine and 10% phenylephrine during ophthalmic surgery.
OBJECTIVE
The recommended concentration of topical phenylephrine for mydriasis is still a matter of debate. Our purpose was to compare the cardiovascular effects of 10% and 2.5% topical aqueous phenylephrine.


METHODS
We carried out a double-masked randomised study on 54 consecutive patients undergoing routine local anaesthetic cataract extraction, comparing the effects on blood pressure and heart rate of either 2.5% or 10% topical aqueous phenylephrine in combination with 1% topical aqueous tropicamide in those with no history of cardiovascular disease.


RESULTS
No difference was found in the rise in blood pressure produced by 2.5% and 10% topical aqueous phenylephrine. We also found no sustained changes in blood pressure or heart rate after instillation of either 2.5% or 10% topical aqueous phenylephrine.


CONCLUSIONS
We recommend the routine use of 2.5% topical aqueous phenylephrine as a mydriatic agent during cataract surgery and acknowledge the role of 10% topical aqueous phenylephrine as an effective mydriatic agent in cases where 2.5% phenylephrine may not be so effective, such as in subjects with darkly pigmented irides.
D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000187:drug effects*; D002387:Cataract Extraction; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D009184:Mydriatics / Q000008:administration & dosage* / Q000494:pharmacology; D010656:Phenylephrine / Q000008:administration & dosage* / Q000494:pharmacology