Anaerobyl is a South African brand of metronidazole, dispensed as 200 mg and 400 mg tablets. It treats infections caused by anaerobic bacteria and certain parasites — dental infections, bacterial vaginosis, trichomoniasis, some gut infections and abscesses. Avoid alcohol during treatment and for the period your label states.

What is Anaerobyl?

Anaerobyl contains metronidazole, supplied in South Africa by Shanur Healthcare as 200 mg and 400 mg tablets. The name is a clue to how it works: it acts against anaerobic organisms, those that grow where there is little or no oxygen.

Metronidazole is a nitroimidazole antimicrobial. It is often called an antibiotic, which is true but incomplete — it works against both anaerobic bacteria and certain single-celled parasites. That combination is why it appears in treatments for infections ordinary antibiotics do not reach.

Anaerobic bacteria thrive in low-oxygen places: deep in gum tissue, inside abscesses, in the bowel, and in the vagina when the normal balance is disturbed. Metronidazole is taken up by these organisms and damages their DNA. Because the process depends on that low-oxygen environment, it has little effect on bacteria that need oxygen — which is why it is often prescribed alongside a second antibiotic rather than instead of one.

It is a Schedule 4 medicine. The same ingredient is dispensed here as plain metronidazole, Flagyl and Bemetrazole among others.

What is Anaerobyl commonly used for?

Anaerobyl is prescribed where anaerobic bacteria or susceptible parasites are involved:

Dental infections and abscesses, frequently with a penicillin such as Betamox.
Bacterial vaginosis, one of its most common uses.
Trichomoniasis, a sexually transmitted infection, where partners are treated together.
Pelvic inflammatory disease, as part of a combination.
Abdominal and pelvic infections, including after surgery.
Skin and soft tissue infections with anaerobic involvement.
Giardiasis and amoebiasis, parasitic gut infections.
Infected leg ulcers and pressure sores.

One point worth addressing directly, because it drives real search interest: Anaerobyl does not treat a yeast infection. Vaginal thrush is fungal, caused by Candida, and needs an antifungal such as clotrimazole or fluconazole. Bacterial vaginosis and thrush produce overlapping symptoms — discharge, irritation — but they are different conditions needing different medicines. Taking metronidazole for thrush will not help and may disturb the vaginal balance further. If you are unsure which you have, a pharmacist or clinic can advise, and testing settles it.

How Anaerobyl fits into this medicine category

Anaerobyl occupies a specific niche among antimicrobials, and understanding it explains why it so often appears as one of two medicines rather than alone.

Penicillins cover common chest, ear, throat and dental organisms. Macrolides cover chest and throat infections and some STIs. Quinolones cover urinary and some gut infections. Tetracyclines cover chest, skin and some STIs. Antifungals treat fungal infections, which no antibacterial touches.

Metronidazole covers what most of those miss. A dental abscess often involves both aerobic and anaerobic bacteria, which is why a dentist may prescribe two medicines — not caution for its own sake, but two different coverages.

Because Anaerobyl is metronidazole, the fuller detail is on the metronidazole guide, and the whole class is on the antibiotics, antifungals and antimicrobials hub.

What to check before using Anaerobyl

Read the alcohol instruction on your label and follow it. This is the caution metronidazole is known for, covered below.

Tell your prescriber or pharmacist if:

You have liver disease.
You have a blood disorder, or have had one.
You have a neurological condition, or develop numbness or tingling during treatment.
You are pregnant, planning pregnancy or breastfeeding.
You take warfarin. Metronidazole increases its effect and raises bleeding risk.
You take lithium, phenytoin or phenobarbitone.
You are being treated for trichomoniasis — partners generally need treating at the same time, or the infection passes back.

Take it with or after food to reduce nausea, and complete the course. Follow the dispensing label for amounts; this page does not set doses.

Possible cautions and when to ask a pharmacist or doctor

Avoid alcohol during treatment and for the period your label states — commonly 48 hours after finishing. The combination can cause flushing, a throbbing headache, nausea, vomiting, abdominal cramps and palpitations. It is unpleasant rather than usually dangerous, and easily avoided. Remember alcohol appears in some cough mixtures, tonics and mouthwashes.

Expect a metallic taste, and possibly nausea, a furred tongue or dry mouth. These settle after the course.

Your urine may darken. This is harmless.

Report numbness or tingling in the hands or feet, which can occur with prolonged use.

Finish the course, and do not save leftovers or take someone else’s. Metronidazole covers a narrow set of organisms — using it for the wrong infection means an untreated infection plus unnecessary side effects.

Seek medical attention for severe or persistent diarrhoea during or after treatment, a rash or swelling of the face or lips, yellowing of the eyes or skin, unusual bruising or bleeding, seizures, or persistent numbness. If symptoms worsen after two or three days, return to the prescriber.

Related medicine guides

Frequently asked questions

What is Anaerobyl 400 used for? Infections involving anaerobic bacteria or certain parasites — dental infections, bacterial vaginosis, trichomoniasis, some gut and pelvic infections, and abscesses.

Is Anaerobyl used for a yeast infection? No. Thrush is fungal and needs an antifungal. Anaerobyl treats bacterial vaginosis, which causes similar symptoms but is a different condition. A pharmacist or clinic can tell them apart.

Can I drink alcohol while taking it? No. Avoid it during treatment and for the period stated on your label. The reaction is well documented and unpleasant.

Is Anaerobyl the same as metronidazole? Yes. Anaerobyl is a South African brand of metronidazole.

Why do I have a metallic taste? It is a common, harmless effect of the medicine and passes when the course finishes.

Does my partner need treatment too? For trichomoniasis, yes — otherwise the infection is passed back. Your prescriber will advise for other infections.

What Is Anaerobyl Used For?