Meds and you

27 September 2013


Metronidazole is an antibiotic effective in treating organisms capable of living in the absence of oxygen.


Metronidazole is the active ingredient of Adco-Metronidazole Tabs (Nappi Code: 742872-009 & 701076-003), Bemetrazole Tabs (Nappi Code: 821705-016 & 788708-023), Bio-Metronidazole Tabs(Nappi Code: 707241-001 & 707242-001), Flagyl Tablets (Nappi Code: 726346-004/012 & 726354-007/015), Flagyl Suspension (Nappi Code: 726338-001), Flagyl Suppositories (Nappi Code: 726303-003 & 726311-006), Flagyl IV Infusion (Nappi Code: 779539-001), Intramed Trichazole Infusion (Nappi Code: 772232-091), Medamet Tabs (Nappi Code: 784710-023), Merck-Metronidazole tabs (Nappi Code: 804916-020), Metazol Tabs (Nappi Code: 793159-059 & , 793167-078), Metrazole Tabs (Nappi Code: 779822- 005/014), Metrostat Tabs (Nappi Code: 783544-111), Sandoz Metronidazole Tabs (Nappi Code: 779342-003), Trichazle Tabs (Nappi Code: 772216-010 & 772224-013) and Zobacide Tabs (Nappi Code: 793035-007).

General information
Metronidazole is an antibiotic effective in treating organisms capable of living in the absence of oxygen.

It is registered for the treatment of Intestinal infections, liver abscesses, sexually transmitted diseases (trichomonas), dental infections and abscesses, and stomach ulcers caused by organisms that are sensitive to metronidazole. When used to treat sexually transmitted diseases, a simultaneous course of treatment is advised for sexual partners.

Alcohol should be avoided for at least 48 hours after finishing treatment. Alcohol may induce a disulfiram reaction which is similar to that that observed with the medication prescribed for alcoholics. It may cause severe nausea and vomiting, accelerated heart rate, shortness of breath and, in severe cases, even death.

To help clear up your infection completely, keep taking this medicine for the full period of treatment, even if you begin to feel better after a few days.

This medicine works best when there is a constant amount in the blood. To help keep the amount constant, do not skip any doses.

How does metronidazole work?
Metronidazole disrupts the helical structure of DNA and inhibits bacterial protein synthesis and replication.

Fast facts

Drug schedule: schedule 4
Available as: metronidazole is available as tablets, suspension, suppositories, cream and as an injection.
What does it do? Metronidazole has an antibiotic effect.
Overdose risk: low
Dependence risk: low
Is Metronidazole available as a generic? yes
Is Metronidazole available on prescription only? Yes

User information

Onset of effect: beneficial effects may only be seen after 24 hours.
Duration of action: up to 12 hours
Dietary advice: avoid concomitant use of alcohol
Stopping this medicine: metronidazole should only be stopped once the prescribed course has been completed.
Prolonged use: not generally prescribed for longer than 10 days. Long term use has been associated with reversible loss of sensation in hands and feet.

Special precautions
Consult your doctor before using this drug if:

  • you have epilepsy

  • you have a liver disease

  • you are taking blood pressure medication

  • you have colitis, Crohn's disease, or any other intestinal disorder

Pregnancy: avoid. Potential risk to the foetus has been reported. Consult your doctor before use, or if you are planning to fall pregnant.
Breastfeeding: avoid. This medication is passed through breast milk and may affect your baby adversely. Consult your doctor before use.
Porphyria: avoid. This medication may cause serious adverse effects. Consult your doctor before use.
Infants and children: a reduction in dose may be necessary.
The elderly: no special precautions need to be taken.
Driving and hazardous work: caution is advised as use of this medication may lead to dizziness, light-headedness and/or sedation. Avoid such activities until you know how this medication affects you.
Alcohol: avoid concomitant use of alcohol with this medication.

Possible side effects

Side Effect
Consult your doctor

Only if severe
In all cases


loss of appetite


metallic taste in mouth


dry mouth


furry tongue










skin rash


bloody diarrhoea




alcohol severe nausea and vomiting may occur
cimetidine increased risk of metronidazole toxicity
lithium increased risk of lithium toxicity
phenobarbitone reduced effect of metronidazole
phenytoin increased risk of phenytoin toxicity
warfarin increased risk of warfarin side effects

Disease interactions
Consult your doctor before using this drug if you have epilepsy, a liver or blood disease, are taking blood pressure medication or if you have colitis, Crohn's disease, or any other intestinal disorder.

Overdose action
A small overdose is no cause for concern. In case of intentional large overdose seek emergency medical attention.

Recommended dosage
Oral: 0.6 - 1.2 g daily
Rectal: 3 g daily
Injection: 1.5 g daily

This material is not intended to substitute medical advice, but is for informational purposes only. Please consult a physician for specific treatment and recommendations.

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