Incompatibility of Y-Site Administered Drugs: the Case of Acyclovir and Ciprofloxacin

Abstract

Multiple drugs administration is a common practice in hospitals and clinics. This is the case when heavy pathologies are treated. In this context, frequently, antivirals and antibiotics are co-administrated either simultaneously or sequentially ignoring potential incompatibilities. In this study, we focused on an antiviral (Acyclovir) and an antibiotic (Ciprofloxacin) compatibility/incompatibility when they co-administrated with special interest on the effect of drugs ratio, pH and delay. By implementing robust HPLC method, we determined the main factors leading to potential modification of concentration of one of the two drugs in the mixture. The results showed that acyclovir is quantitatively recovered in all conditions related to pH, concentration and time (up to 24 hours). However, ciprofloxacin is strongly altered in acidic and basic conditions, the quantity of ciprofloxacin and time after mixing the two drugs. The most valuable piece of information is that the ratio of acyclovir/ciprofloxacin is crucial. The latter should be calculated and managed to provide at least two fold quantity of acyclovir versus ciprofloxacin in order to maintain the administrated doses and warrant efficient therapeutic effect.