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Pylera Side Effects

Generic name: bismuth subcitrate potassium / metronidazole / tetracycline

Medically reviewed by Last updated on Jul 3, 2022.

Note: This document contains side effect information about bismuth subcitrate potassium / metronidazole / tetracycline. Some of the dosage forms listed on this page may not apply to the brand name Pylera.

For the Consumer

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


Oral route (Capsule)

Potential for CarcinogenicityMetronidazole has been shown to be carcinogenic in mice and rats. It is unknown whether metronidazole is associated with carcinogenicity in humans.

Side effects requiring immediate medical attention

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

  • Belching
  • chills
  • cough
  • darkened urine
  • diarrhea
  • fever
  • general feeling of discomfort or illness
  • headache
  • heartburn
  • indigestion
  • joint pain
  • loss of appetite
  • muscle aches and pains
  • nausea
  • pains in the stomach, side, or abdomen, possibly radiating to the back
  • runny nose
  • shivering
  • sore or dry throat
  • stomach discomfort, upset, or pain
  • sweating
  • trouble sleeping
  • unusual tiredness or weakness
  • vomiting
  • yellow eyes or skin

Less common

  • Back pain
  • black, tarry stools
  • body aches or pain
  • burning feeling in the chest or stomach
  • burning while urinating
  • chest pain
  • dizziness
  • fast, irregular, pounding, or racing heartbeat or pulse
  • frequent urination
  • hoarseness
  • increased volume of pale, dilute urine
  • 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
  • pale skin
  • 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
  • unusual bleeding or bruising
  • voice changes


  • Bloated feeling
  • excess air or gas in the stomach or bowels
  • feeling of fullness
  • pain or tenderness around the eyes and cheekbones
  • passing gas
  • skin rash
  • tightness of the chest
  • trouble breathing

Incidence not known

  • Blistering, peeling, loosening of the skin
  • blurred or decreased vision
  • burning, numbness, tingling, or painful sensations
  • clumsiness
  • itching
  • pressure in the stomach
  • red irritated eyes
  • red skin lesions, often with a purple center
  • sores, ulcers, or white spots in the mouth or on the lips
  • swelling of the stomach area
  • unsteadiness or awkwardness
  • weakness in the arms, hands, legs, or feet
  • white patches in the mouth or throat or on the tongue

Side effects not requiring immediate medical attention

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]

More about Pylera (bismuth subcitrate potassium / metronidazole / tetracycline)

Patient resources

Professional resources

Related treatment guides


1. "Product Information. Pylera (bismuth subcitrate potassium/metronidazo/TCN)." Aptalis Pharma (2022):

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.