Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
The most common adverse reactions (≥ 1%) reported in clinical trials when all three components of this therapy were given concomitantly are listed in Table 1 below. The majority of the adverse reactions were related to the gastrointestinal tract, were reversible, and infrequently led to discontinuation of therapy.
Table 1: Incidence of Adverse Reactions Reported in Clinical Trials (≥ 1%)† | Bismuth Subsalicylate, Metronidazole, and Tetracycline ‡ (N = 266) |
| Adverse Reactions | % Patients |
| Nausea | 12.0 |
| Diarrhea | 6.8 |
| Abdominal Pain | 6.8 |
| Melena | 3.0 |
| Upper Respiratory Infection | 2.3 |
| Constipation | 1.9 |
| Anorexia | 1.5 |
| Asthenia | 1.5 |
| Vomiting | 1.5 |
| Discolored Tongue* | 1.5 |
| Headache | 1.5 |
| Dyspepsia | 1.5 |
| Dizziness | 1.5 |
| Stool Abnormality** | 1.1 |
| Duodenal Ulcer | 1.1 |
| Sinusitis | 1.1 |
| Taste Perversion*** | 1.1 |
| Flatulence | 1.1 |
| GI Hemorrhage | 1.1 |
| Pain | 1.1 |
| Insomnia | 1.1 |
| Anal Discomfort | 1.1 |
| Paresthesia | 1.1 |
* darkening of the tongue
** black or dark stools
*** metallic taste
† Includes reactions reported at ≥1% in patients taking bismuth subsalicylate, metronidazole, and tetracycline in Studies 1, 2, 3, and 4 (see CLINICAL STUDIES).
‡ In Studies 1, 2, and 3(N = 197), most patients were on concomitant acid suppression therapy.
The additional adverse reactions (< 1%) reported in clinical trials when all three components of this therapy were given concomitantly are listed below and divided by body system:
Gastrointestinal: dry mouth, dysphagia, eructation, GI monilia, glossitis, intestinal obstruction, rectal hemorrhage, stomatitis
Skin: acne, ecchymosis, photosensitivity reaction (see PRECAUTIONS), pruritus, rash
Cardiovascular: cerebral ischemia, chest pain, hypertension, myocardial infarction
CNS: nervousness, somnolence
Musculoskeletal: arthritis, rheumatoid arthritis, tendonitis
Metabolic: SGOT increase, SGPT increase
Urogenital: urinary tract infection
Other: conjunctivitis, flu syndrome, infection, malaise, neoplasm, rhinitis, syncope, tooth disorder
Other Important Adverse Reactions from Labeling for the Individual Components of Bismuth Subsalicylate Chewable Tablets/Metronidazole Tablets/Tetracycline Hydrochloride Capsules
Metronidazole
Blood and Lymphatic system disorders: Reversible neutropenia (leucopenia) in cases of prolonged treatment; rarely reversible thrombocytopenia however no persistent hematological abnormalities attributable to metronidazole have been observed (see PRECAUTIONS).
Cardiac disorders: Flattening of the T-wave may be seen in electrocardiographic tracings.
Gastrointestinal disorders: Nausea, vomiting, diarrhea, abdominal pain, constipation, anorexia, metallic taste, furry tongue, glossitis, stomatitis and candida overgrowth (see PRECAUTIONS).
Hypersensitivity/Immune system disorders: Urticaria, erythematous rash, Stevens-Johnson syndrome, toxic epidermal necrolysis, flushing, nasal congestion, dryness of the mouth (or vagina or vulva), and fever (see CONTRAINDICATIONS).
Metabolism and nutrition disorders: Pancreatitis.
Nervous system disorders: Convulsive seizures, encephalopathy, aseptic meningitis, optic and peripheral neuropathy, headache, syncope, dizziness, vertigo, incoordination, ataxia, confusion, dysarthria, irritability, depression, weakness, and insomnia (see WARNINGS).
Dermatologic disorders: Erythematous rash and pruritus.
Renal and urinary disorders: Dysuria, cystitis, polyuria, incontinence, darkened urine, and a sense of pelvic pressure.
Other: Dyspareunia, decrease of libido, proctitis, joint pains.
Tetracycline Hydrochloride
Blood and lymphatic system disorders: Hemolytic anemia, thrombocytopenia, thrombocytopenic purpura, neutropenia, and eosinophilia.
Gastrointestinal disorders: Nausea, vomiting, diarrhea, anorexia, glossitis, black hairy tongue, dysphagia, enterocolitis, inflammatory lesions (with Candida overgrowth) in the anogenital region, esophagitis and esophageal ulceration.
Nervous system disorders: Intracranial hypertension including pseudotumor cerebri, tinnitus, and myasthenic syndrome.
Renal and urinary disorders: Increased BUN.
Skin and subcutaneous tissue disorders: Maculopapular and erythematous rashes, DRESS syndrome (drug rash with eosinophilia and systemic symptoms), Steven-Johnson syndrome, toxic epidermal necrolysis, erythema multiforme, onycholysis, discoloration of the nails, exfoliative dermatitis and photosensitivity have been rarely reported (see WARNINGS).
Liver: Hepatotoxicity and liver failure.
Hypersensitivity reactions: Urticaria, angioedema, anaphylaxis, Henoch-Schonlein purpura, pericarditis, exacerbation of systemic lupus erythematosus, and serum sickness-like reactions.