Metronidazole & Alcohol

[mhb08112]

Right MRPharmS, here's one for you...

I understand that obviously metronidazole inhibits acetaldehyde (ethanal) dehydrogenase and therefore, when alcohol (ethanol) is consumed it can lead to an accumulation of ethanal, and therefore the horrible side effects (disulfiram-like reaction)...

My question is, how long must alcohol be avoided after taking a course of metronidazole? Does it depend on the strength and length of the course? No Pharmacist I have asked (total is now 5) has been able to give me a proper answer, or direct me to apporpriate reading...

And a very specific example here, how long would one advise someone taking 2g stat of metronidazole (for bacterial vaginosis) to not drink for?


I'd appreciate any input, cheers

[bleepholder]

The elimination half-life of metronidazole is about 8 hours; that of the hydroxy metabolite is slightly longer. The half-life of metronidazole is reported to be longer in neonates and in patients with severe hepatic impairment; that of the hydroxy metabolite is prolonged in patients with substantial renal impairment.

Metronidazole is readily and almost completely absorbed after oral doses. Peak plasma concentrations of about 6 and 12 micrograms/mL occur, usually within 1 to 2 hours, after single doses of 250 and 500 mg respectively. Some accumulation occurs and consequently there are higher concentrations when multiple doses are given.

However, an analysis of published reports (3) and a study in healthy subjects (4) both found that there was no convincing evidence of a disulfiram-like reaction between metronidazole and alcohol, although caution was still advised.

3= Williams CS, Woodcock KR. Do ethanol and metronidazole interact to produce a disulfiram-like reaction? Ann Pharmacother 2000; 34: 255–7.
4= Visapää J-P, et al.. Lack of disulfiram-like reaction with metronidazole and ethanol. Ann Pharmacother 2002; 36: 971–4.

Ok so i ahve been lazy and copied and pasted from martindale lol.....and i couldn't be bothered looking at the journal articles, but interesting what martindale has to say!!

it doesn't answer your question, but maybe its a start

[mhb08112]

More helpful than most, thank you very much!

So... Martindale are saying the chances of a Disulfiram-like reaction are slim?
I've seen one in the community (well, what was apparently one), a lady's tongue turned completely yellow... Was some sight!

[johnep]

I used to advise 48 hours.
johnep

[bleepholder]

that seems fairly reasonable...prob better than trying to work out the half life of the drug and then seeing how long it would take for it to leave the body...it can't be that hard to avoid alcohol for up to 7 days whilst your on abx!!

if i was that ill to warrant abx, then painting the town red would be the last thing on my mind!!

[Nik]

if i was that ill to warrant abx, then painting the town red would be the last thing on my mind!!

Clearly you have not worked in the rougher parts of brum. And how many people are truly ill enough to warrant antibiotics ?

[bleepholder]

lol true!! antibiotics are for wimps!

i stick to the mean streets of nottingham anyway!!

[Nik]

i stick to the mean streets of nottingham anyway!!

Last time I checked there was a gang of merry men along with a man who robs from the rich and gives to the poor to keep the streets safe.

[bleepholder]

Last time I checked there was a gang of merry men along with a man who robs from the rich and gives to the poor to keep the streets safe.

well if you see this guy, send him in my direction!

[bobbin]

My question is, how long must alcohol be avoided after taking a course of metronidazole?

The manufacturers state that alcohol should be avoided for at least 48 hours after the last dose of metronidazole.