Brown R H, Wood T S, Lynch M G, Schoenwald R D, Chien D S, Jennings L W
Department of Ophthalmology, University of Texas Health Science Center, Dallas 75235.
Ophthalmology. 1987 Jul;94(7):847-50. doi: 10.1016/s0161-6420(87)33538-9.
This study examined the effect of reducing eyedrop volume on the efficacy and systemic absorption of a given quantity of phenylephrine hydrochloride. Aqueous phenylephrine hydrochloride (2.5%) given in the commercially available drop volume of 32 microliters was compared with 10% aqueous phenylephrine given in an 8-microliters volume. Both preparations contained the same total amount of phenylephrine per drop. Ten subjects had both eyes dilated with each of the phenylephrine solutions according to a randomized, double-crossover sequence. The mean final pupillary diameter was nearly 1.0 mm larger for the 8-microliters drop (P = 0.0033). Nine of ten subjects achieved a larger pupillary diameter with the 8-microliters drop. Systemic absorption, as measured by plasma phenylephrine level, was similar for the two drop volumes. Thus, the 8-microliters drop achieved a significantly larger pupillary dilation without an increase in systemic absorption. Phenylephrine may have the most favorable risk-benefit ratio when administered as a high concentration in a small volume.
本研究考察了减少滴眼液体积对一定量盐酸去氧肾上腺素疗效及全身吸收的影响。将市售滴体积为32微升的2.5%盐酸去氧肾上腺素水溶液与8微升体积的10%盐酸去氧肾上腺素水溶液进行比较。两种制剂每滴中去氧肾上腺素的总量相同。10名受试者按照随机、双交叉顺序，用每种去氧肾上腺素溶液对双眼进行散瞳。8微升滴剂的最终平均瞳孔直径比32微升滴剂大近1.0毫米（P = 0.0033）。10名受试者中有9名使用8微升滴剂时瞳孔直径更大。通过血浆去氧肾上腺素水平测量的全身吸收情况，两种滴体积相似。因此，8微升滴剂在不增加全身吸收的情况下实现了显著更大的瞳孔散大。当以高浓度小体积给药时，去氧肾上腺素可能具有最有利的风险效益比。
