Description and Brand Names

Drug information provided by: Merative, Micromedex®

US Brand Name

1. Flagyl IV
2. Flagyl IV RTU

Descriptions

Metronidazole injection is used to treat serious bacterial infections in different areas of the body. It is also used to prevent infections in the bowels before and after surgery for some patients.

Metronidazole belongs to the class of medicines known as antibiotics. It works by killing bacteria or preventing their growth. However, this medicine will not work for colds, flu, or other virus infections.

This medicine is to be given only by or under the direct supervision of your doctor.

This product is available in the following dosage forms:

• Solution

Before Using

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies have not been performed on the relationship of age to the effects of metronidazole injection in the pediatric population. Safety and efficacy have not been established.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of metronidazole injection in the elderly. However, elderly patients are more likely to have unwanted effects and age-related liver problems, which may require caution and an adjustment in the dose for patients receiving metronidazole injection.

Breastfeeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Drug Interactions

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are receiving this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

• Amprenavir
• Bepridil
• Cisapride
• Disulfiram
• Dronabinol
• Dronedarone
• Mesoridazine
• Pimozide
• Saquinavir
• Sparfloxacin
• Terfenadine
• Thioridazine
• Ziprasidone

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Alfuzosin
• Amiodarone
• Amitriptyline
• Anagrelide
• Apomorphine
• Aripiprazole
• Aripiprazole Lauroxil
• Arsenic Trioxide
• Asenapine
• Astemizole
• Atazanavir
• Azithromycin
• Bedaquiline
• Buprenorphine
• Bupropion
• Buserelin
• Busulfan
• Capecitabine
• Ceritinib
• Chloroquine
• Chlorpromazine
• Cholera Vaccine, Live
• Ciprofloxacin
• Citalopram
• Clarithromycin
• Clofazimine
• Clomipramine
• Clozapine
• Crizotinib
• Cyclobenzaprine
• Dabrafenib
• Dasatinib
• Degarelix
• Delamanid
• Desipramine
• Deslorelin
• Deutetrabenazine
• Disopyramide
• Dofetilide
• Dolasetron
• Domperidone
• Donepezil
• Doxepin
• Doxifluridine
• Droperidol
• Ebastine
• Efavirenz
• Encorafenib
• Entrectinib
• Eribulin
• Erythromycin
• Escitalopram
• Famotidine
• Felbamate
• Fingolimod
• Flecainide
• Fluconazole
• Fluorouracil
• Fluoxetine
• Formoterol
• Foscarnet
• Fosphenytoin
• Galantamine
• Gatifloxacin
• Gemifloxacin
• Glasdegib
• Gonadorelin
• Goserelin
• Granisetron
• Halofantrine
• Haloperidol
• Histrelin
• Hydroquinidine
• Hydroxychloroquine
• Hydroxyzine
• Ibutilide
• Iloperidone
• Imipramine
• Inotuzumab Ozogamicin
• Itraconazole
• Ivabradine
• Ivosidenib
• Ketoconazole
• Lapatinib
• Levofloxacin
• Lofexidine
• Lumefantrine
• Macimorelin
• Mebendazole
• Mefloquine
• Methadone
• Mifepristone
• Mizolastine
• Moxifloxacin
• Mycophenolate Mofetil
• Mycophenolic Acid
• Nafarelin
• Nelfinavir
• Nilotinib
• Norfloxacin
• Octreotide
• Ofloxacin
• Olanzapine
• Ondansetron
• Osimertinib
• Oxaliplatin
• Ozanimod
• Paliperidone
• Panobinostat
• Papaverine Hydrochloride
• Paroxetine
• Pasireotide
• Pazopanib
• Pentamidine
• Perphenazine
• Pimavanserin
• Pipamperone
• Pitolisant
• Posaconazole
• Probucol
• Procainamide
• Prochlorperazine
• Promethazine
• Propafenone
• Protriptyline
• Quetiapine
• Quinidine
• Quinine
• Ranolazine
• Ribociclib
• Risperidone
• Ritonavir
• Selpercatinib
• Sertindole
• Sertraline
• Sevoflurane
• Siponimod
• Sodium Phosphate
• Sodium Phosphate, Dibasic
• Sodium Phosphate, Monobasic
• Solifenacin
• Sorafenib
• Sotalol
• Sulpiride
• Sunitinib
• Tacrolimus
• Tamoxifen
• Tegafur
• Telaprevir
• Telavancin
• Telithromycin
• Tetrabenazine
• Tolterodine
• Toremifene
• Trazodone
• Trimipramine
• Triptorelin
• Vandetanib
• Vardenafil
• Vemurafenib
• Venlafaxine
• Vilanterol
• Vinflunine
• Voclosporin
• Voriconazole
• Vorinostat
• Warfarin
• Zuclopenthixol

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Carbamazepine
• Cholestyramine
• Cyclosporine
• Lithium
• Milk Thistle

Other Interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following is not recommended. Your doctor may decide not to treat you with this medication, change some of the other medicines you take, or give you special instructions about the use of food, alcohol, or tobacco.

• Ethanol

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Blood or bone marrow problems, or history of or
• Brain disease (eg, aseptic meningitis, encephalopathy) or
• Edema (too much fluid in the body) or
• Leukopenia (low white blood cells), history of or
• Optic neuropathy (eye disease with vision changes), history of or
• Oral thrush (Candida infection) or
• Peripheral neuropathy (nerve problem), history of or
• Seizures, history of or
• Vaginal yeast infection (Candida infection)—Use with caution. May make these conditions worse.

• Cockayne syndrome (genetic disorder)—Use with caution. May increase the risk of liver problems, which may be life-threatening.

• Kidney disease, end-stage or
• Liver disease, severe—Use with caution. The effects may be increased because of slower removal of the medicine from the body.

Proper Use

A nurse or other trained health professional will give you this medicine in a hospital. It is given through a needle placed into one of your veins.

Your doctor will give you a few doses of this medicine until your condition improves, and then switch you to an oral medicine that works the same way. If you have any concerns about this, talk to your doctor.

Precautions

It is important that your doctor check your progress while you are receiving this medicine. This is to make sure that the infection is cleared up. Blood tests may be needed to check for unwanted effects.

You should not receive metronidazole if you have taken disulfiram (Antabuse®) within the last 2 weeks. Using these medicines together may cause serious unwanted effects.

Drinking alcoholic beverages while you are receiving this medicine may cause stomach pain, nausea, vomiting, headache, or flushing or redness of the face. Other alcohol-containing preparations (eg, elixirs, cough syrups, tonics) may also cause problems. This medicine may also cause alcoholic beverages to taste different. You should not drink alcoholic beverages or take other alcohol-containing preparations while you are receiving this medicine and for at least 3 days after stopping it.

Check with your doctor right away if you have dizziness, problems with muscle control or coordination, shakiness or an unsteady walk, slurred speech, or trouble with speaking. These may be symptoms of a serious brain condition called encephalopathy.

Check with your doctor right away if you are having burning, numbness, tingling, or painful sensations in the arms, hands, legs, or feet. These could be symptoms of a condition called peripheral neuropathy.

Call your doctor right away if you have confusion, drowsiness, fever, a general feeling of illness, a headache, loss of appetite, nausea, a stiff neck or back, or vomiting. These could be symptoms of a serious condition called aseptic meningitis.

This medicine may increase your risk of having serious liver problems, which may be life-threatening. This is more likely if you have Cockayne syndrome (rare form of dwarfism). Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, vomiting, or yellow eyes or skin.

Serious skin reactions can occur with this medicine. Check with your doctor right away if you have blistering, peeling, or loosening of the skin, red skin lesions, severe acne or a skin rash, sores or ulcers on the skin, or fever or chills with this medicine.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

More common

1. Agitation
2. back pain
3. blindness
4. blurred vision
5. burning, numbness, tingling, or painful sensations in the hands or feet
6. confusion
7. decreased vision
8. dizziness
9. drowsiness
10. eye pain
11. fever
12. headache
13. irritability
14. mood or mental changes
15. nausea
16. seeing or hearing things that are not there
17. seizures
18. stiff neck or back
19. unsteadiness or awkwardness
20. unusual tiredness or weakness
21. vomiting
22. weakness in the arms, hands, legs, or feet

Incidence not known

1. Black, tarry stools
2. blistering, peeling, or loosening of the skin
3. changes in skin color
4. changes in speech patterns
5. chest pain
6. chills
7. cough
8. diarrhea
9. fainting
10. feeling of warmth
11. itching
12. joint or muscle pain
13. lower back or side pain
14. pain, tenderness, or swelling of the foot or leg
15. painful or difficult urination
16. pale skin
17. red skin lesions, often with a purple center
18. red, irritated eyes
19. redness of the face, neck, arms, and occasionally, upper chest
20. shakiness and unsteady walk
21. slurred speech
22. sore throat
23. sores, ulcers, or white spots in the mouth or on the lips
24. trouble with speaking
25. unsteadiness, trembling, or other problems with muscle control or coordination
26. unusual bleeding or bruising

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known

1. Dry mouth
2. hives or welts
3. redness of the skin
4. skin rash
5. stomach discomfort
6. stuffy nose
7. unpleasant metallic taste

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Portions of this document last updated: March 01, 2021

Original article: https://www.mayoclinic.org/drugs-supplements/metronidazole-intravenous-route/description/drg-20074581