Patient Medication Information: uses, side effects, how to take - Apo-Metronidazole
Serious warnings and precautions box
- Cases of severe skin reactions (Severe Cutaneous Adverse Reactions (SCAR)) have been reported with metronidazole. Stop using APO-METRONIDAZOLE at the first sign of rash, sores or other skin reactions. For more information read the “Serious side effects and what to do about them” table, below.
What APO-METRONIDAZOLE is used for:
APO-METRONIDAZOLE is used to treat adults with:
- Infections of the genital tract (such as trichomoniasis: a sexually transmitted infection, bacterial vaginosis: bacterial infection of the vagina);
- Infections of the brain, lung or stomach area (abdominal cavity)
It is also used to treat adults and children with:
- Amebiasis (a parasitic infection of the liver or intestines)
- Giardisasis (a parasitic infection in the intestines)
Antibacterial and antiprotozoal drugs like APO-METRONIDAZOLE treat only bacterial and protozoal infections. They do not treat viral infections such as the common cold.
How APO-METRONIDAZOLE works:
APO-METRONIDAZOLE belong to a group of medicines called antibacterial – antiprotozoal.
APO-METRONIDAZOLE works by killing bacteria and parasites (protozoans) that cause infections in your body.
The ingredients in APO-METRONIDAZOLE are:
Medicinal ingredient: metronidazole.
Non-medicinal ingredients: colloidal silicon dioxide, croscarmellose sodium, and stearic acid.
The capsule shell contains the following non-medicinal ingredients: D&C red #33, D&C yellow #10, FD&C blue #1, FD&C green #3, gelatin, talc (antistatic agent), and titanium dioxide.
The edible ink used to imprint the capsule shells contains the following non-medicinal ingredients: D&C yellow #10 aluminum lake, FD&C blue #1 aluminum lake, FD&C blue #2 aluminum lake, FD&C red #40 aluminum lake, iron oxide black, propylene glycol, and shellac glaze.
APO-METRONIDAZOLE comes in the following dosage form:
Capsules, 500 mg.
Do not use APO-METRONIDAZOLE if:
- You are allergic (hypersensitive) to metronidazole, nitroimidazole (e.g., tinidazole) or any of the ingredients in APO-METRONIDAZOLE, or components of the container (see “The ingredients in APO-METRONIDAZOLE are:”).
- You have a genetic disorder called Cockayne syndrome. Severe liver damage that may be fatal has happened when people with Cockayne syndrome have taken metronidazole.
- You have a disease of the nervous system.
- You have a history of blood problems.
- Have hypothyroidism (underactive thyroid gland) or hypoadrenalism (underactive adrenal glands).
To help avoid side effects and ensure proper use, talk to your healthcare professional before you take APO-METRONIDAZOLE. Talk about any health conditions or problems you may have, including if you:
Are pregnant, think you are pregnant, or plan to get pregnant.
- Are breastfeeding, or planning to breastfeed, as metronidazole is excreted in human breast milk.
- Have other infections
- Have liver problems.
- Have kidney problems.
- Are taking APO-METRONIDAZOLE for the first time or have any nervous system problems.
- Have any blood disorder (e.g., leukemia, hemophilia, or other). Your healthcare professional may order periodic blood tests.
Other warnings you should know about:
APO-METRONIDAZOLE may darken your urine and this is not considered a concern.
Driving and Operating Machinery
- Do NOT drive any type of vehicle or use any tools or machinery if:
- You feel confused, dizzy or experience vertigo (spinning sensation).
- You see or hear things that are not there (hallucinations).
- You have a seizure.
- You have an eye problem, like blurred or double vision.
Reproductive Health
If a sexual partner shows signs of infection, the partner should be examined and treated by the doctor as well.
Tell your healthcare professional about all the medicines you take, including any drugs, vitamins, minerals, natural supplements or alternative medicines.
The following may interact with APO-METRONIDAZOLE:
- Blood thinners, such as warfarin
- Lithium, a drug used to treat bipolar disorder.
- Phenobarbital, a drug used to treat anxiety or to control seizures.
- Phenytoin, a drug used to control seizures.
- 5-fluorouracil, a drug used to treat cancer.
- Busulfan, a drug used to treat cancer.
- Cyclosporin, a drug used to suppress the immune system.
- Disulfiram, a drug used to treat drinking problems.
- Vecuronium, an agent used to relax muscles during surgical procedures.
- Medications that may cause heart rhythm changes (QT prolongation), like certain antiarrhythmics (medicines for heart rhythm disorders), certain antibiotics, and psychotropic medicines.
Do not drink any alcohol while you are taking APO-METRONIDAZOLE and for at least 1 day after finishing your course. Drinking alcohol while using APO-METRONIDAZOLE might cause side effects, such as feeling sick (nausea), being sick (vomiting), stomach pain, hot flushes, very fast or uneven heartbeat (palpitations) and headache.
APO-METRONIDAZOLE may interact with some blood tests. Tell your healthcare professional if you have any upcoming blood tests while you are taking APO-METRONIDAZOLE.
How to take APO-METRONIDAZOLE:
- You should not be left unattended for 2 hours after your first use of APO-METRONIDAZOLE.
- Although you may feel better early in treatment, APO-METRONIDAZOLE should be used exactly as directed.
- Misuse or overuse of APO-METRONIDAZOLE could lead to the growth of bacteria/ protozoans that will not be killed by metronidazole (bacterial/protozoan resistance). This means that metronidazole may not work for you in the future.
- Do not share your medicine with anyone.
Usual dose:
Your healthcare professional will decide how much APO-METRONIDAZOLE you should take depending on the type of infection you have and your medical history.
The 250 mg strength is not marketed by Apotex Inc.
Adults (18 years and older):
The usual dose is 250 mg to 750 mg every 8 to 12 hours for 5 to 10 days.
Children (under 18 years old):
The usual dose is 25 to 50 mg/kg/day divided into 2 to 3 doses each day for 5 to 7 days.
Overdose:
If you think you, or a person you are caring for, have taken too much APO-METRONIDAZOLE, contact a healthcare professional, hospital emergency department, regional poison control centre or Health Canada’s toll-free number, 1-844 POISON-X (1-844-764-7669) immediately, even if there are no signs or symptoms.
Missed Dose:
If you forget to take APO-METRONIDAZOLE, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose. Do not use a double dose to make up for a forgotten dose.
Possible side effects from using APO-METRONIDAZOLE:
These are not all the possible side effects you may have when taking APO-METRONIDAZOLE. If you experience any side effects not listed here, tell your healthcare professional.
These side effects may include:
- Unpleasant taste in the mouth
- Furred tongue or tongue discoloration
- Feeling sick (nausea), being sick (vomiting), upset stomach, stomach pain or diarrhea
- Hearing loss
- Noise such as buzzing, ringing, or whistling heard in the ear
- Loss of appetite
- Feeling sleepy or dizzy
- Vaginal dryness and burning
Serious side effects and what to do about them
| Frequency/Side Effect/Symptom | Talk to your healthcare professional | Stop taking this drug and get immediate medical help | |
|---|---|---|---|
| Frequency/Side Effect/Symptom | Talk to your healthcare professional | Stop taking this drug and get immediate medical help | |
| Frequency/Side Effect/Symptom | Talk to your healthcare professional | Stop taking this drug and get immediate medical help | |
| Only if severe | In all cases | ||
| Only if severe | In all cases | ||
| Only if severe | In all cases | ||
| Allergic reaction: difficulty swallowing or breathing, wheezing; drop in blood pressure; feeling sick to your stomach and throwing up; hives or rash; swelling of the face, lips, tongue or throat | √ | ||
Severe Cutaneous Adverse Reactions (severe skin reactions that may also affect other organs):
| √ | ||
| |||
| Diarrhea | √ | ||
| Liver problems: yellowing of your skin and eyes (jaundice), right upper stomach area pain or swelling, nausea or vomiting, unusual tiredness | √ | ||
| Nervous system problems: inability to coordinate voluntary movements, problems using your arms and legs, problems with speaking or feel confused, convulsions, tingling sensation on the skin, stiff neck associated with headache, extreme sensitivity to bright light | √ | ||
| Fever, unexpected infections, mouth ulcers, bruising, bleeding gums, or extreme tiredness | √ | ||
| Posterior Reversible Encephalopathy Syndrome (brain swelling): Headache, confusion, visual disturbances, seizures | √ | ||
| Meningitis (inflammation of the thin tissue that surrounds the brain | √ | ||
| and spinal cord): sudden, high fever, severe headache, stiff neck, confusion, nausea and vomiting | |||
| Pancreatitis (inflammation of the pancreas): severe abdominal pain which may reach through to your back, especially associated with nausea, vomiting and fatigue | √ | ||
| Eyesight problems: blurred or double vision | √ | ||
| Feeling depressed | √ | ||
| Pain in your eyes | √ | ||
| Mental health problems: irrational thoughts, hallucinations, feeling confused or feeling depressed | √ | ||
| Thoughts or actions of self-harm or suicide | √ | ||
| Vertigo (spinning sensation) | √ | ||
| Numbness, tingling, pain, or a feeling of weakness, in the arms or legs | √ | ||
| Blood problems (change in the number of white blood cells or blood platelets): infections, fatigue, fever, aches, pains and flu-like symptoms, bruising or bleeding for longer than usual if you hurt yourself | √ | ||
Heart problems: very fast or uneven heartbeat, chest pain, dizziness, weakness, blurred vision, fainting. This may also happen when APO-METRONIDAZOLE is taken with drugs that can cause QT prolongation (a heart rhythm condition). | √ | ||
| Gastrointestinal problems: Abdominal pain, cramps, diarrhea with possible bloody stools | √ | ||
If you have a troublesome symptom or side effect that is not listed here or becomes bad enough to interfere with your daily activities, tell your healthcare professional.
Reporting side effects
You can report any suspected side effects associated with the use of health products to Health Canada by:
- Visiting the Web page on Adverse Reaction Reporting (canada.ca/drug-device-reporting) for information on how to report online, by mail or by fax; or
- Calling toll-free at 1-866-234-2345.
NOTE: Contact your healthcare professional if you need information about how to manage your side effects. The Canada Vigilance Program does not provide medical advice.
Storage:
APO-METRONIDAZOLE (Metronidazole Capsules) should be stored between 15°C - 25°C.
Keep out of reach and sight of children.
If you want more information about APO-METRONIDAZOLE:
- Talk to your healthcare professional
- Find the full product monograph that is prepared for healthcare professionals and includes the Patient Medication Information by visiting the Health Canada Drug Product Database website (https://www.canada.ca/en/health-canada/services/drugs-health-products/drug-products/drug-product-database.html); the manufacturer’s website (http://www.apotex.ca/products); or by calling 1-800-667-4708.
Date of Authorization: 2026-05-28