EFFECT OF HALOTHANE ON THE REPLICATION OF ANIMAL VIRUSES

Five RNA- and 2 DNA-containing viruses were propagated in Vero [African green monkey kidney] cells and tested for their ability to replicate in the presence of halothane (2-bromo-2-chloro-1,1,1-trifluoroethane), a commonly used inhalational anesthetic. Halothane did not affect poliovirus replication at any anesthetic concentration tested; all other viruses were partially or totally inhibited by clinical doses of the anesthetic. Replication of Sendai virus, SV-40, vesicular stomatitis virus and herpes simplex virus type 1 were moderately inhibited by halothane exposure. At concentrations of 2.2% (vol/vol) halothane, peak virus titers were reduced by .apprx. 2 orders of magnitude for vesicular stomatitis virus and SV-40, 3.5 orders of magnitude for Sendai virus and 4 orders of magnitude for herpes simplex virus. Newcastle disease virus and measles virus were the most susceptible to exposure to halothane. Total inhibition of the replication of these viruses occurred at 1.6-2.0% halothane. All of the viruses whose replication was susceptible to the action of halothane were inhibited in a concentration-dependent manner. With the exception of simian virus 40, the inhibition of the replication of all viruses was reversible after halothane removal, although total recovery of virus synthesis was not observed unless the culture medium was changed or the pH was adjusted after anesthetic removal.