How long do antibiotics stay in your blood/system?

[figleaf]

My dentist gave me some for a gum infection. I`m allergic to penicillan so its one of the other sorts of antibiotics I have. I finish the course today. The leaflet gives a HUGE list of things you cant have or take with these including alcohol!!!
How long after you stop taking the tablets are they gone from your blood stream/system - anyone know?

It depends on the antibiotic, some have a longer half life than others, which one are you on, and is this for drinking purposes?

its usually about a week

whats that based on big lips?

but its depends on what anibiotics it is

Good indication of therapeutic half-life is how often you have to take them - if it's every 3 hrs, then they're obviously metabolised fairly quickly, if only once a day, less so.

I'd leave at least 24h after the last dose before you start doing contra-indicated things.

half life means the time it takes for an antibiotic to half in its effectiveness, the reason most antibiotics are taken three times a day is because they have a reletivly short half life.
Even metronidazole, which is the only antibiotic you should not drink with has a hal life of 8 hours. I would think a week would be a bit excessive to wait...

x posted mrs bager, sorry

The tablets are 200 mg Metronidazole . I am taking 3 a day. Primarily I`m interested if I can drink this weekend but I then wondered how long it would lurk in my blood/body.

Guidelines reccommened between one and two days after you finnish the course. The reaction is pretty awful so I would go with caustion and say two days. However that is a fairly low dose. Basically In some people, not all. Metronidazole stop the liver from metabolizing alcohol properly and causes very obvious facial flushing nausia, with even a tiny bit of alcohol.\link{http://www.nhsdirect.nhs.uk/chq.asp?Classid=14&Articleid=864\this might help}
hope this does not spoil your weekend

The knowledge held collectively on Mumsnet is Amazing.
Thanks for that Chapsmum. Drinking aside though, howlong before the drug will have left my sysyem?

48 hours from your last dose and it will be gone! It will be at a none theraputic dose in 8 hours but unless you have poor liver function, it should be all gone 48 hours from your last dose

HTH

I know its probably a legal requirement in terms of information passing to the consumer but the leaflet makes the drug sound really scary!

Forgot to add thanks for that.

Hi, i am someone who has worked on coatings and delivery systems for all sorts of companies and for different types of medicines. Most of what has been said here is accurate, but with wrong conclusions being drawn. We must differentiate the difference between half life and life cycle, while half life gives an indication of a how quickly the drug last before it breaks down, life cycle is determined by the quantity, dosage, frequency and delivery system. Ie a short half life may have a larger dosage to compensate. Different drugs work in different ways, assuming the frequency of dosage can indictate the medicines ‘life cycle’ can lead to overdosing. Many delivery systems (tablet coatings) will take into account a drugs half life and can bypass the stomach altogether and slow release the medicine directly into the intestine. For instance, paracetamol may still be active ( life cycle ) up to 12 hours after ingestion, hence the restrictions in dosage over a 24 hour period. Amoxicillin has a half life of 2 hours, but dosages take this into account and are normally larger than other antibiotics, the end result with amoxicillin is to have it still be effective ( life cycle again ) at least 48 hours after ingestion. Some antibiotics work for up to 14-16 days after ingestion.
My advice is, follow the manufacturer guidelines, read the leaflet, ask your doctor or even better, ask your local pharmacist, they have specific training on these topics and have reference guides on specific medicines which get updated regularly.
Hope this helps future people looking for answers to this and similar questions.