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Bismuth subcitrate potassium / metronidazole / tetracycline Side Effects

For the Consumer

Applies to bismuth subcitrate potassium / metronidazole / tetracycline: oral capsule

Along with its needed effects, bismuth subcitrate potassium/metronidazole/tetracycline 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 bismuth subcitrate potassium/metronidazole/tetracycline:

More common Less common
  • Back pain
  • body aches or pain
  • burning feeling in the chest or stomach
  • chest pain
  • congestion
  • dizziness
  • fast, irregular, pounding, or racing heartbeat or pulse
  • hoarseness
  • itching of the vagina or genital area
  • lack or loss of strength
  • lower back or side pain
  • pain during sexual intercourse
  • painful or difficult urination
  • rash with flat lesions or small raised lesions on the skin
  • sneezing
  • stuffy nose
  • tender, swollen glands in the neck
  • tenderness in the stomach area
  • thick, white vaginal discharge with no odor or with a mild odor
  • trouble with swallowing
  • voice changes
  • Bloated
  • excess air or gas in the stomach or intestines
  • full feeling
  • pain or tenderness around the eyes and cheekbones
  • passing gas
  • skin rash
  • tightness of the chest
  • trouble breathing

Some side effects of bismuth subcitrate potassium / metronidazole / tetracycline 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
  • Black or dark tongue
  • black stools
Less common
  • Change in taste, or bad, unusual, or unpleasant aftertaste
  • dry mouth
  • fear or nervousness

For Healthcare Professionals

Applies to bismuth subcitrate potassium / metronidazole / tetracycline: oral capsule


The most commonly reported side effects included abnormal feces, nausea, and diarrhea.[Ref]


Very common (10% or more): Abnormal feces (up to 15.6%)
Common (1% to 10%): Nausea, diarrhea, abdominal pain, dyspepsia, constipation, dry mouth
Frequency not reported: Flatulence, glossitis, vomiting, tongue darkening, gastritis, gastroenteritis, duodenal ulcer
Postmarketing reports: Abdominal distention, eructation, flatulence, pseudomembranous colitis/Clostridium difficile colitis

Frequency not reported: Nausea, vomiting, diarrhea, abdominal pain, constipation, furry tongue, glossitis, stomatitis, dry mouth, pancreatitis

Frequency not reported: Nausea, vomiting, diarrhea, glossitis, black hairy tongue, dysphagia, enterocolitis, anogenital region inflammatory lesions/inflammatory lesions with Candida overgrowth, esophagitis, esophageal ulceration[Ref]

Nervous system

Common (1% to 10%): Headache, dysgeusia, dizziness
Frequency not reported: Somnolence
Postmarketing reports: Peripheral neuropathy

Frequency not reported: Metallic taste, convulsive seizures, encephalopathy, aseptic meningitis, peripheral neuropathy, headache, syncope, dizziness, vertigo, incoordination, ataxia, dysarthria

Frequency not reported: Intracranial hypertension, pseudotumor cerebri[Ref]


Common (1% to 10%): Asthenia, abnormal laboratory tests
Frequency not reported: Malaise
Postmarketing reports: Fatigue, candidiasis

Frequency not reported: Candida overgrowth, fever, weakness

Frequency not reported: Tinnitus[Ref]


Common (1% to 10%): Vaginal infection, urine abnormality

Frequency not reported: Vaginal/vulvar dryness, dysuria, polyuria, incontinence, darkened urine, pelvic pressure, dyspareunia, proctitis[Ref]


Common (1% to 10%): ALT increase, AST increase

Frequency not reported: Hepatotoxicity, liver failure[Ref]


Common (1% to 10%): Maculopapular rash
Uncommon (0.1% to 1%): Rash
Frequency not reported: Pruritus
Postmarketing reports: Stevens-Johnson syndrome, toxic epidermal necrolysis, drug rash with eosinophilia and systemic symptoms (DRESS)

Frequency not reported: Urticaria, erythematous rash, pruritus

Frequency not reported: Maculopapular/erythematous rash, onycholysis, nail discoloration, exfoliative dermatitis, photosensitivity, urticaria, Henoch-Schonlein purpura, systemic lupus erythematosus exacerbation[Ref]


Frequency not reported: Chest pain, tachycardia
Postmarketing reports: Chest discomfort

Frequency not reported: T-wave flattening, flushing

Frequency not reported: Pericarditis[Ref]


Frequency not reported: Increased appetite, increased weight

Frequency not reported: Anorexia

Frequency not reported: Anorexia[Ref]


Frequency not reported: Back pain, increased blood creatinine phosphokinase, myalgia

Frequency not reported: Joint pain

Frequency not reported: Myasthenic syndrome[Ref]


Frequency not reported: Visual disturbance

Frequency not reported: Optic neuropathy[Ref]


Frequency not reported: Reversible neutropenia/leukopenia, reversible thrombocytopenia

Frequency not reported: Hemolytic anemia, thrombocytopenia, thrombocytopenic purpura, neutropenia, eosinophilia


Frequency not reported: Cystitis

Frequency not reported: Increased blood urea nitrogen


Frequency not reported: Anxiety

Frequency not reported: Confusion, irritability, depression, insomnia, decreased libido[Ref]


Frequency not reported: Angioedema, anaphylaxis[Ref]


Frequency not reported: Serum sickness-like reaction[Ref]


Frequency not reported: Nasal congestion[Ref]


1. "Product Information. Pylera (bismuth subcitrate potassium/metronidazo/TCN)." Aptalis Pharma, Birmingham, AL.

Some side effects of bismuth subcitrate potassium / metronidazole / tetracycline may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.