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Metro IV Side Effects

Generic Name: metronidazole

Note: This document contains side effect information about metronidazole. Some of the dosage forms listed on this page may not apply to the brand name Metro IV.

For the Consumer

Applies to metronidazole: oral capsule, oral powder for suspension, oral suspension, oral tablet, oral tablet extended release

Other dosage forms:

Along with its needed effects, metronidazole (the active ingredient contained in Metro IV) 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 immediately if any of the following side effects occur while taking metronidazole:

More Common

  • Agitation
  • back pain
  • blindness
  • blurred vision
  • burning, numbness, tingling, or painful sensations in the hands or feet
  • changes in speech patterns
  • confusion
  • decreased vision
  • depression
  • dizziness
  • drowsiness
  • eye pain
  • fever
  • headache
  • irritability
  • lack of coordination
  • nausea
  • seeing or hearing things that are not there
  • seizures
  • shakiness and unsteady walk
  • slurred speech
  • stiff neck or back
  • trouble speaking
  • unsteadiness, trembling, or other problems with muscle control or coordination
  • unusual tiredness or weakness
  • vomiting
  • weakness in the arms, hands, legs, or feet

Less Common

  • Black, tarry stools
  • blood in the urine
  • body aches or pain
  • chills
  • clumsiness or unsteadiness
  • difficulty with breathing
  • ear congestion
  • feeling of pelvic pressure
  • frequent or painful urination
  • loss of voice
  • nasal congestion
  • pinpoint red spots on the skin
  • runny nose
  • skin rash, hives, redness, itching
  • sneezing
  • stomach and back pain (severe)
  • unusual bleeding or bruising
  • vaginal irritation, discharge, or dryness not present before taking the medicine

Rare

  • Bleeding gums
  • bloating
  • chest pain
  • constipation
  • cough
  • dark urine
  • fast heartbeat
  • indigestion
  • loss of appetite
  • painful or difficult urination
  • pains in the stomach, side, or abdomen, possibly radiating to the back
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • swollen glands
  • yellow eyes or skin

Incidence Not Known

  • Blistering, peeling, or loosening of the skin
  • bloody or cloudy urine
  • burning while urinating
  • continuing diarrhea
  • continuing stomach pain
  • diarrhea
  • feeling of warmth
  • increased volume of pale, dilute urine
  • joint or muscle pain
  • loss of bladder control
  • red skin lesions, often with a purple center
  • red, irritated eyes
  • redness of the face, neck, arms, and occasionally, upper chest
  • redness of the skin

Some side effects of metronidazole 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:

More Common

  • Dizziness or lightheadedness
  • feeling of constant movement of self or surroundings
  • heartburn
  • sensation of spinning
  • stomach cramps
  • trouble sleeping
  • weight loss

Rare

  • Change in taste sensation
  • congestion
  • dry mouth
  • pain or tenderness around the eyes and cheekbones
  • tender, swollen glands in the neck
  • trouble with swallowing
  • unpleasant or sharp metallic taste
  • voice changes

Incidence Not Known

  • Decreased interest in sexual intercourse
  • inability to have or keep an erection
  • loss in sexual ability, desire, drive, or performance
  • painful sexual intercourse

For Healthcare Professionals

Applies to metronidazole: compounding powder, intravenous powder for injection, intravenous solution, oral capsule, oral suspension, oral tablet, oral tablet extended release

General

The most serious side effects reported were convulsive seizures, encephalopathy, aseptic meningitis, and optic and peripheral neuropathy (characterized by numbness or paresthesia of an extremity).[Ref]

Nervous system

Very common (10% or more): Headache (up to 18%)

Common (1% to 10%): Taste metallic, dizziness

Rare (0.01% to 0.1%): Drowsiness, ataxia, peripheral neuropathy, transient epileptiform seizure, encephalopathy

Very rare (less than 0.01%): Acute cerebellar syndrome, paralysis, dysarthria, gait impaired, nystagmus, tremor, convulsion, incoordination

Frequency not reported: Convulsive seizure, headache, syncope, paresthesia, optic neuritis, peripheral sensory neuropathy[Ref]

Gastrointestinal

Very common (10% or more): Nausea (up to 10%)

Common (1% to 10%): Abdominal pain, diarrhea, dry mouth, vomiting, stomatitis, glossitis

Rare (less than 0.1%): Pancreatitis, mucositis, epigastralgia

Frequency not reported: Epigastric pain/distress, abdominal cramping, constipation, furry tongue, glossitis, stomatitis, oral mucositis, taste disorder, dyspepsia, pseudomembranous colitis, tongue discolored[Ref]

Genitourinary

Very common (10% or more): Vaginitis (15%)

Common (1% to 10%): Pruritus genital, urine abnormal, dysmenorrhea, moniliasis, urinary tract infection

Rare (less than 0.1%): Darkened urine

Frequency not reported: Vaginal dryness, vulva dryness, dysuria, polyuria, incontinence, pelvic pressure, cystitis, candida infection proliferated, dyspareunia, procitiits, pyuria[Ref]

Other

Common (1% to 10%): Bacterial infection, influenza-like symptoms, weakness

Rare (less than 0.1%): Fever, aseptic meningitis

Frequency not reported: Vertigo, tinnitus, hearing impaired, hearing loss, sensorineural hearing loss, overgrowth of Candida, disulfiram-like reaction[Ref]

Respiratory

Common (1% to 10%): Upper respiratory tract infection, rhinitis, sinusitis, pharyngitis

Frequency not reported: Nasal congestion, hiccup[Ref]

Hematologic

Uncommon (0.1% to 1%): Leukopenia

Rare (less than 0.1%): Neutropenia, neutropenia reversible, thrombocytopenia, pancytopenia, agranulocytosis, blood dyscrasia

Frequency not reported: Bone marrow aplasia, bone marrow depression[Ref]

Cardiovascular

Frequency not reported: Flat T-wave, flushing, QT interval prolonged[Ref]

Dermatologic

Common (1% to 10%): Pruritus

Rare (0.01% to 0.1%): Stevens-Johnson Syndrome, toxic epidermal necrolysis, skin rash, erythema multiforme, pustulosis, Quincke edema

Very rare (less than 0.01%): Fixed drug eruption

Frequency not reported: Erythematosus rash, pruritus, urticaria, mild erythematous eruption, pustular eruption, angioedema[Ref]

Local

Frequency not reported: Thrombophlebitis[Ref]

Psychiatric

Very rare (less than 0.01%): Confusion, hallucination, psychotic disorder

Frequency not reported: Irritability, depression, insomnia, libido decreased, psychosis, disorientation, psychotic reaction, depressed mood[Ref]

Ocular

Rare (0.01% to 0.1%): Optic neuropathy, diplopia, myopia

Very rare (less than 0.01%): Light sensitivity, vision disorder

Frequency not reported: Vision blurred, visual acuity decreased, color vision change[Ref]

Metabolic

Rare (less than 0.1%): Anorexia[Ref]

Musculoskeletal

Common (1% to 10%): Myalgia

Very rare (less than 0.01%): Stiff neck, arthralgia

Frequency not reported: Fleeting joint pain[Ref]

Oncologic

Frequency not reported: Breast cancer, colon cancer[Ref]

Hepatic

Rare (0.01% to 0.1%): Cholestatic hepatitis, liver function test abnormal

Very rare (less than 0.01%): Mixed hepatitis, hepatocellular injury, jaundice, liver failure, liver transplant

Frequency not reported: Drug-induced hepatitis, liver enzymes increased[Ref]

Immunologic

Rare (less than 0.1%): Anaphylaxis, anaphylactic shock, Herxheimer reaction

Frequency not reported: Reaction serum sickness-like, hypersensitivity reaction[Ref]

References

1. Cerner Multum, Inc. "Australian Product Information." O 0

2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

3. "Product Information. Flagyl (metronidazole)." Searle, Skokie, IL.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

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