Open AccessComparison of Intrathecal Concentrations of Acyclovir following Epidural and Intravenous Administration in Rats
Author(s) -
Sang Sik Choi
Publication year - 2016
Publication title -
pain physician
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.31
H-Index - 99
eISSN - 2150-1149
pISSN - 1533-3159
DOI - 10.36076/ppj/2019.19.e613
Subject(s) - medicine , epidural administration , dose , cerebrospinal fluid , varicella zoster virus , anesthesia , intrathecal , route of administration , group b , aciclovir , group a , gastroenterology , virus , herpesviridae , immunology , bupivacaine , viral disease
Background: Herpes zoster is a disease caused by reactivation of varicella-zoster virus in sensorycranial nerves and dorsal root ganglion. Our presumption was that epidural administration ofacyclovir near the viral burden could be more advantageous than intravenous (IV) administration.The cerebrospinal fluid (CSF) concentration of acyclovir after epidural administration wasdetermined to be higher than that after IV administration in rats.Objective: In this study, we tested the hypothesis that the concentration of acyclovir in CSF afterepidural administration is higher than that achieved after IV administration in rats.Study Design: A randomized controlled animal trial.Methods: A total of 30 adult male Sprague-Dawley rats were used. The rats were randomlydivided into 2 equal groups, epidural (Group Epi) and IV (Group IV) administration groups (n =15). Group Epi was further subdivided into 3 groups according to acyclovir dosage; each groupcomprised 5 animals receiving injections at dosages of 0.3 mg, 0.6 mg, and 0.9 mg. Group IV wasalso subdivided into 3 groups receiving dosages of 3 mg, 6 mg, and 9 mg. We measured CSF andplasma acyclovir concentrations one hour after administration.Results: In Group Epi, the median plasma concentrations of acyclovir were lower than that in CSF(P < 0.05). In Group IV, the median plasma concentrations of acyclovir were significantly higherthan that in CSF (P < 0.05). The CSF concentrations of acyclovir in Group Epi were significantlyhigher than that in Group IV (P < 0.05). The plasma concentrations of acyclovir in Group Epi weresignificantly lower than that in Group IV (P < 0.05).Limitations: There were no references of equivalent dosages of acyclovir between IV andepidural administration. However, it is obvious in this study that epidural administration of a lowdose of acyclovir can more effectively increase its concentration in the intrathecal space than IVadministration.Conclusions: Epidural administration of acyclovir provides superior drug concentrations in theintrathecal space compared to IV administration.Key words: Acyclovir, epidural injection, herpes zoster, varicella zoster virus