Bismuth Subcitrate Potassium / Metronidazole / Tetracycline Side Effects

Medically reviewed by Drugs.com. Last updated on Nov 17, 2024.

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

Important warnings This medicine can cause some serious health issues

Oral route (capsule)

Potential for Carcinogenicity. Metronidazole has been shown to be carcinogenic in mice and rats.

It is unknown whether metronidazole is associated with carcinogenicity in humans.

Serious side effects

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 side effects

• 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 side effects

• 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

Rare side effects

• 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

Other side effects

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 side effects

• black or dark tongue
• black stools

Less common side effects

• 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.

General adverse events

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

Gastrointestinal

• 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

Metronidazole:

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

Tetracycline:

• 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

Metronidazole:

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

Tetracycline:

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

Other

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

Metronidazole:

• Frequency not reported: Candida overgrowth, fever, weakness

Tetracycline:

• Frequency not reported: Tinnitus^[Ref]

Genitourinary

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

Metronidazole:

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

Hepatic

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

Tetracycline:

• Frequency not reported: Hepatotoxicity, liver failure^[Ref]

Dermatologic

• 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)

Metronidazole:

• Frequency not reported: Urticaria, erythematous rash, pruritus

Tetracycline:

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

Cardiovascular

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

Metronidazole:

• Frequency not reported: T-wave flattening, flushing

Tetracycline:

• Frequency not reported: Pericarditis^[Ref]

Metabolic

• Frequency not reported: Increased appetite, increased weight

Metronidazole:

• Frequency not reported: Anorexia

Tetracycline:

• Frequency not reported: Anorexia^[Ref]

Musculoskeletal

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

Metronidazole:

• Frequency not reported: Joint pain

Tetracycline:

• Frequency not reported: Myasthenic syndrome^[Ref]

Ocular

• Frequency not reported: Visual disturbance

Metronidazole:

• Frequency not reported: Optic neuropathy^[Ref]

Hematologic

Metronidazole:

• Frequency not reported: Reversible neutropenia/leukopenia, reversible thrombocytopenia

Tetracycline:

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

Renal

Metronidazole:

• Frequency not reported: Cystitis

Tetracycline:

• Frequency not reported: Increased blood urea nitrogen

Psychiatric

• Frequency not reported: Anxiety

Metronidazole:

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

Hypersensitivity

Tetracycline:

• Frequency not reported: Angioedema, anaphylaxis^[Ref]

Immunologic

Tetracycline:

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

Respiratory

Metronidazole:

• Frequency not reported: Nasal congestion^[Ref]

Further information

Bismuth subcitrate potassium/metronidazole/tetracycline side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer