May 23 2022

Active ingredient: ciprofloxacin

According to data from animal experiments, ciprofloxacin increases several times the effect of ethanol on sleep duration induced by this last [1], depending on dose and route of administration.

Many colon aerobic bacteria possess alcohol dehydrogenase activity (ADH) and are capable of transforming ethanol to acetaldehyde. Consequently, a portion of the ingested alcohol can be metabolized in the colon by these microorganisms. Has been recently demonstrated that this pathway may contribute up to by 9% to the elimination of ethanol in experimental animals.

Available data suggest that the reduction caused by ciprofloxacin of the amount of aerobic bacteria in the colon and of the intestinal ADH activity is primarily responsible for the decrease in the rate of elimination of alcohol in experimental animals fed with this substance prolongedly[2].

Human treatment with ciprofloxacin reduces the rate of alcohol elimination by about 9.4%, with a concordant decrease both the ADH activity as transformation of alcohol into acetaldehyde. Since the antibacterial substance has no effect on hepatic blood flow, the enzymatic activity of ADH or CYP2E1, the most likely cause of this decrease in the elimination of alcohol is the reduction of bowel bacterial activity [3]. The end result is a prolongation of the effects of alcohol in patients receiving ciprofloxacin while concurrently are taking alcoholic beverages.


1: Strzelec JS, Kubik-Bogucka E, Czarnecka E. Influence of fluoroquinolones on the main action of ethanol. Pol J Pharmacol. 1999 Jan-Feb, 51 (1) :71-8 .1
2: Nosova T, Jokelainen K, Kaihovaara P, Keva V? ? ? inen S, Rautio M, Jousimies-Somer H, Salaspuro M. Ciprofloxacin ethanol administration enhanced decreases elimination in ethanol-fed rats. Alcohol Alcohol. 1999 Jan-Feb, 34 (1) :48-54.
3: Tillonen J, Homann N, Rautio M, Jousimies-Somer H, Salaspuro M. Ciprofloxacin decreases the rate of ethanol elimination in humans. Gut. 1999 Mar, 44 (3) :347-52.