Medically reviewed by Jessica Swirble, PharmD
Last updated on 3/18/2024

Drug Information | Side Effects | Use & Dosage | Request a Prescription

The use of metronidazole has been shown to cause side effects in some patients.

Common mild side effects of metronidazole use include:

• Nausea
  
• Vomiting
  
• Diarrhea
  
• Abdominal pain or cramping
  
• Upset stomach
  
• Headache
  
• Metallic taste in the mouth
  
• Dry mouth
  
• Dizziness or lightheadedness
  
• Tongue irritation
  
• Yeast infection
  
• Vaginal discharge and irritation (vaginal gel)
  
  

More severe side effects include:

• Allergic reactions (rash, itching, swelling of the face, lips, or tongue, difficulty breathing)
  
• Severe skin reactions (blistering, peeling, redness)
  
• Neurological symptoms (numbness, tingling, burning sensations, coordination problems)
  
• Seizures or convulsions
  
• Blood disorders (decreased white blood cell count, decreased platelets)
  
• Liver dysfunction (jaundice, dark urine, abdominal pain)
  
  

Seek medical attention immediately if you experience any severe symptoms while taking metronidazole. If you experience mild side effects that become severe or do not go away after a few days, speak to a healthcare provider right away.

Tell your healthcare provider about any existing medical conditions, allergies, or other medications you are taking before starting treatment with metronidazole. This includes prescription drugs, over-the-counter medications, and dietary supplements, as they may interact with this drug.

Tell your provider if you are taking these medications or supplements:

• Blood thinners (anticoagulants)
  
• Azithromycin
  
• Disulfiram (used to treat alcohol dependence)
  
• Cimetidine (used to reduce stomach acid)
  
• Citalopram
  
• Clarithromycin
  
• Haloperidol
  
• Levofloxacin
  
• Lithium (used to treat mood disorders)
  
• Methadone
  
• Phenobarbital or phenytoin (anticonvulsants)
  
• Ritonavir
  
• Warfarin (an anticoagulant)
  
• Ziprasidone
  
• Carbamazepine (used to treat seizures and nerve pain)
  
  

You should also mention medical conditions such as:

• Allergic reactions to medications
  
• Liver disease
  
• Blood disorders
  
• Neurological disorders or seizures
  
• Kidney disease
  
  

If you are pregnant, planning to become pregnant, or breastfeeding, consult your healthcare provider before using metronidazole to assess potential risks and benefits.

Avoid consuming alcohol or products containing alcohol, as it may cause a reaction (flushing, nausea, vomiting, rapid heartbeat).

Take metronidazole with food to minimize stomach upset.

Use caution when driving or operating machinery, as metronidazole may cause dizziness or drowsiness.

Your healthcare provider will provide specific instructions regarding the use of metronidazole with food, beverages, and other medications. It's essential to follow their guidance to ensure the effectiveness of the treatment and minimize the risk of side effects.

The symptoms of a metronidazole overdose include:

• Nausea
  
• Vomiting
  
• Loss of coordination
  
  

If you experience any of these symptoms, call the poison control helpline at 1-800-222-1222. If an individual has collapsed, is having seizures, or is unresponsive, call 9-1-1 immediately.