PYLERA Capsule Ref.[50501] Active ingredients: Methronidazole Tetracycline Tripotassium dicitrato bismuthate

5.1 Potential for Carcinogenicity

Metronidazole, a component of PYLERA, has been shown to be carcinogenic in mice and rats. Tumors affecting the liver, lungs, mammary and lymphatic tissues have been detected in several studies of metronidazole in rats and mice, but not hamsters [see Nonclinical Toxicology (13)]. It is unknown whether metronidazole is associated with carcinogenicity in humans.

5.2 Fetal Toxicity

Tetracycline can cause fetal harm when administered to a pregnant woman. Based on animal data, use of drugs of the tetracycline class during the second and third trimester of pregnancy can cause permanent discoloration of the teeth (yellow-gray brown) and possibly inhibit bone development [see Warnings and Precautions (5.4)]. Administration of oral tetracycline to pregnant rats at various doses resulted in yellow fluorescence in teeth and bones in the newborn animals. If PYLERA is used during pregnancy, or if the patient becomes pregnant while taking PYLERA, advise the patient of the potential risk to the fetus [see Contraindications (4.6) and Use in Specific Populations (8.1)].

5. 3 Maternal Toxicity

Tetracycline, a component of PYLERA, administered during pregnancy at high doses (>2 g IV) was associated with rare but serious cases of maternal hepatotoxicity. This syndrome may result in stillborn or premature birth due to maternal pathology [see Contraindications (4.6) and Use in Specific Populations (8.1)].

5.4 Tooth Enamel Discoloration and Hypoplasia

The use of drugs of the tetracycline class during tooth development (last half of pregnancy, infancy, and childhood to the age of 8 years) may cause permanent discoloration of the teeth (yellow-gray-brown). This adverse reaction is more common during long-term use of the drug, but has been observed following repeated short-term courses. Enamel hypoplasia has also been reported. PYLERA, therefore, should not be used in this age group unless other drugs are not likely to be effective or are contraindicated [see Use in Specific Populations (8.4)].

5.5 Central and Peripheral Nervous System Effects

Metronidazole: Convulsive seizures, encephalopathy, aseptic meningitis and peripheral neuropathy (including optic neuropathy) have been reported. Encephalopathy has been reported in association with cerebellar toxicity characterized by ataxia, dizziness, and dysarthria. CNS lesions seen on MRI have been described in reports of encephalopathy. CNS symptoms are generally reversible within days to weeks upon discontinuation of metronidazole. CNS lesions seen on MRI have also been described as reversible. Peripheral neuropathy, mainly of sensory type has been reported and is characterized by numbness or paresthesia of an extremity. Aseptic meningitis symptoms may occur within hours of dose administration and generally resolve after metronidazole therapy is discontinued.

Tetracycline: Intracranial hypertension (IH), including pseudotumor cerebri, has been associated with the use of tetracyclines. Clinical manifestations of IH include headache, blurred vision, diplopia, and vision loss; papilledema can be found on fundoscopy. Women of childbearing age who are overweight or have a history of IH are at greater risk for developing tetracycline associated IH. Concomitant use of isotretinoin should be avoided because isotretinoin is also known to cause IH.

Although IH typically resolves after discontinuation of treatment, the possibility for permanent visual loss exists. If visual disturbance occurs during treatment, prompt ophthalmologic evaluation is warranted. Since intracranial pressure can remain elevated for weeks after drug cessation, patients should be monitored until they stabilize.

Bismuth-containing products: Cases of neurotoxicity associated with excessive doses of various bismuth-containing products have been reported. Effects have been reversible with discontinuation of bismuth therapy.

The appearance of abnormal neurologic signs and symptoms demands the prompt evaluation of the benefit/risk ratio of the continuation of PYLERA therapy [see Adverse Reactions (6.3)].

5.6 Development of Potential for Microbial Overgrowth

Known or previously unrecognized candidiasis may present more prominent symptoms during therapy with metronidazole and requires treatment with an antifungal agent. As with other antibacterial drugs, use of tetracycline hydrochloride may result in overgrowth of nonsusceptible organisms, including fungi. If superinfection occurs, discontinue PYLERA and institute appropriate therapy.

5.7 Photosensitivity

Photosensitivity, manifested by an exaggerated sunburn reaction, has been observed in patients taking tetracycline [see Adverse Reactions (6.3)]. Patients apt to be exposed to direct sunlight or ultraviolet light should be advised that this reaction can occur with tetracycline drugs. Instruct patients taking PYLERA to avoid exposure to the sun or sun lamps. Discontinue treatment at the first evidence of skin erythema.

5.8 Darkening of the Tongue and/or Black Stool

Bismuth subcitrate potassium may cause temporary and harmless darkening of the tongue and/or black stools, generally reversible within several days after treatment is stopped [see Adverse Reactions (6.1)]. Stool darkening should not be confused with melena.

5.9 Use in Patients with Blood Dyscrasias

Metronidazole is a nitroimidazole, and should be used with care in patients with evidence of or history of blood dyscrasia. A mild leukopenia has been observed during its administration; however, no persistent hematologic abnormalities attributable to metronidazole have been observed in clinical studies. Total and differential leukocyte counts are recommended before and after therapy [see Adverse Reactions (6.3)].

5.10 Increase d Drug Plasma Concentrations in Patients with Hepatic I mpairment

Patients with hepatic impairment metabolize metronidazole slowly, with resultant accumulation of metronidazole in the plasma. Patients with mild to moderate hepatic impairment should be monitored for metronidazole associated adverse events. PYLERA is not recommended in patients with severe hepatic impairment (Child-Pugh C) [see Clinical Pharmacology (12.3)].

5.11 Laboratory Test Interactions

Bismuth absorbs x-rays and may interfere with x-ray diagnostic procedures of the gastrointestinal tract.

Bismuth subcitrate potassium may cause a temporary and harmless darkening of the stool. However, this change does not interfere with standard tests for occult blood.

Metronidazole may interfere with certain types of determinations of serum chemistry values, such as aspartate aminotransferase (AST, SGOT), alanine aminotransferase (ALT, SGPT), lactate dehydrogenase (LDH), triglycerides, and hexokinase glucose. Values of zero may be observed. All of the assays in which interference has been reported involve enzymatic coupling of the assay to oxidation-reduction of nicotinamide (NAD+ <=> NADH). Interference is due to the similarity in absorbance peaks of NADH (340 nm) and metronidazole (322 nm) at pH 7.

5.12 Development of Drug Resistant Bacteria

Prescribing PYLERA in the absence of a proven or strongly suspected bacterial infection is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.

5.13 Cutaneous Reactions

Skin and subcutaneous disorders including Stevens-Johnson syndrome, toxic epidermal necrolysis and DRESS syndrome (drug rash with eosinophilia and systemic symptoms) have been reported. Discontinue treatment at the first evidence of a cutaneous reaction [see Adverse Reactions (6.2)].

5.14 Drug Interactions

Oral Contraceptives

Concurrent use of PYLERA with oral contraceptive may make oral contraceptives less effective due to an interaction with the tetracycline component of PYLERA. Breakthrough bleeding has been reported. Advise women of child-bearing potential to use a different or additional form of contraception while taking PYLERA [see Drug Interactions (7.4)].

Anticoagulants

PYLERA may alter the anticoagulant effects of warfarin and other oral coumarin anticoagulants. Metronidazole has been reported to potentiate the anticoagulant effect of warfarin, and other oral coumarin anticoagulants, resulting in a prolongation of prothrombin time. Tetracycline has been shown to depress plasma prothrombin activity. Closely monitor prothrombin time, International Normalized Ratio (INR), or other suitable anticoagulation tests if PYLERA is administered concomitantly with warfarin. Patients should also be monitored for evidence of bleeding [see Drug Interactions (7.5)].

Lithium

In patients stabilized on relatively high doses of lithium, short-term use of PYLERA may cause elevation of serum lithium concentrations and signs of lithium toxicity due to the interaction between metronidazole and lithium. Monitor serum lithium and serum creatinine concentrations daily for several days after beginning treatment with PYLERA to detect any increase that may precede clinical symptoms of lithium toxicity [see Drug Interactions (7.6)].

Busulfan

Metronidazole has been reported to increase plasma concentrations of busulfan, which can result in an increased risk for serious busulfan toxicity. Do not administer PYLERA concomitantly with busulfan unless the benefit outweighs the risk. If no therapeutic alternatives to PYLERA are available, and concomitant administration with busulfan is medically needed, monitor for busulfan toxicity and busulfan plasma concentrations and adjust the busulfan dose accordingly [see Drug Interactions (7.8)].

Drugs that Prolong the QT interval

QT prolongation has been reported with metronidazole, a component of PYLERA, particularly when administered with drugs with the potential for prolonging the QT interval.

6.3 Other Important Adverse Reactions from Labeling for the Individual Components of PYLERA

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 Warnings and Precautions (5.9)].

Cardiac disorders: QT prolongation has been reported with metronidazole, particularly when administered with drugs with the potential for prolonging the QT interval. 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.

Hypersensitivity/Immune system disorders: Urticaria, erythematous rash, flushing, nasal congestion, dryness of the mouth (or vagina or vulva), and fever [see Contraindications (4.6)].

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 and Precautions (5.5)].

Dermatologic disorders: Erythematous rash and pruritus.

Renal and urinary disorders: Dysuria, cystitis, polyuria, incontinence, darkened urine, and a sense of pelvic pressure.

Hepatic: Cases of severe irreversible hepatotoxicity/acute liver failure, including cases with fatal outcomes with very rapid onset after initiation of systemic use of metronidazole, have been reported in patients with Cockayne Syndrome (latency from drug start to signs of liver failure as short as 2 days) [see Contraindications (4.4)].

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, onycholysis, discoloration of the nails, exfoliative dermatitis and photosensitivity have been rarely reported [see Warnings and Precautions (5.13)].

Liver: Hepatotoxicity and liver failure.

Hypersensitivity reactions: Urticaria, angioedema, anaphylaxis, Henoch-Schonlein purpura, pericarditis, exacerbation of systemic lupus erythematosus, and serum sickness-like reactions.

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 safety of PYLERA plus omeprazole (OBMT) to eradicate Helicobacter pylori was assessed in an open-label, randomized, active-controlled clinical trial conducted in North America. The duration of treatment was 10 days with 147 patients exposed to PYLERA plus omeprazole (OBMT) and 152 exposed to control, consisting of omeprazole, amoxicillin, and clarithromycin (OAC). The age of the population in the study ranged from 18 to 75 years, with 59% male patients and 59% Caucasian patients.

Adverse drug reactions were reported in 58% of patients in the OBMT group and 59% of patients in the OAC group. There were no adverse reactions leading to discontinuation of the study during the clinical trial.

Adverse reactions with an incidence of ≥5% in OBMT group include abnormal feces, diarrhea, nausea, and headache. Adverse drug reactions with an incidence of ≥ 5% in OAC group include diarrhea, dysgeusia, dyspepsia, nausea and headache.

Table 2 lists adverse reactions with an incidence of ≥1%, in either groups (OBMT vs OAC) and in order of decreasing incidence for the OBMT group.

Table 2. Adverse reactions with an incidence of ≥1% from North American trial, [n (%)]:

^* OBMT = Omeprazole + PYLERA
^** OAC = Omeprazole + Amoxicillin + Clarithromycin;
^*** Dark stools [see Warnings and Precautions (5.8)]

Adverse reactions with an incidence of <1% for OBMT group are: back pain, vomiting, tongue darkening [see Warnings and Precautions (5.8)], anxiety, gastritis, gastroenteritis, myalgia, chest pain, increased appetite, blood creatine phosphokinase increased, malaise, somnolence, tachycardia, duodenal ulcer, visual disturbance, weight increased.

Additionally, the following adverse reactions, presented by system organ class in alphabetical order, have been identified during post approval use of PYLERA. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

• Gastrointestinal disorders: abdominal distention, eructation, flatulence
• General disorders and administration site conditions: chest discomfort, fatigue
• Infections and infestations: candidiasis, pseudomembranous colitis (Clostridium difficile colitis)
• Nervous Systems: peripheral neuropathy
• Skin and subcutaneous disorders: Stevens-Johnson syndrome, toxic epidermal necrolysis, DRESS syndrome (drug rash with eosinophilia and systemic symptoms)

7.1 Methoxyflurane

Do not administer methoxyflurane to patients taking PYLERA. The concurrent use of tetracycline hydrochloride, a component of PYLERA, with methoxyflurane has been reported to result in fatal renal toxicity [see Contraindications (4.1)].

7.2 Disulfiram

Psychotic reactions have been reported in alcoholic patients who are using metronidazole, a component of PYLERA and disulfiram concurrently. PYLERA should not be given to patients who have taken disulfiram within the last two weeks [see Contraindications (4.2)].

7.3 Alcohol

Consumption of alcoholic beverages or administration of other products containing propylene glycol during treatment with PYLERA and for at least 3 days afterwards may cause a disulfiram-like reaction (abdominal cramps, nausea, vomiting, headaches, and flushing) due to the interaction between alcohol or propylene glycol and metronidazole, a component of PYLERA. Discontinue alcoholic beverage or other products containing propylene glycol during and for at least 3 days after therapy with PYLERA [see Contraindications (4.3)].

7.4 Oral Contraceptives

Concurrent use of PYLERA with oral contraceptive may make oral contraceptives less effective due to an interaction with the tetracycline component of PYLERA. Breakthrough bleeding has been reported. Women of child-bearing potential should use a different or additional form of contraception while taking PYLERA [see Warnings and Precautions (5.14)].

7.5 Anticoagulants

PYLERA may alter the anticoagulant effects of warfarin and other oral coumarin anticoagulants. Metronidazole has been reported to potentiate the anticoagulant effect of warfarin, and other oral coumarin anticoagulants, resulting in a prolongation of prothrombin time. Tetracycline has been shown to depress plasma prothrombin activity. Prothrombin time, International Normalized Ratio (INR), or other suitable anticoagulation tests should be closely monitored if PYLERA is administered concomitantly with warfarin. Patients should also be monitored for evidence of bleeding [see Warnings and Precautions (5.14)].

7.6 Lithium

In patients stabilized on relatively high doses of lithium, short-term use of PYLERA may cause elevation of serum lithium concentrations and signs of lithium toxicity due to the interaction between metronidazole and lithium. Serum lithium and serum creatinine concentrations should be monitored several days after beginning treatment with PYLERA to detect any increase that may precede clinical symptoms of lithium toxicity [see Warnings and Precautions (5.14)].

7.7 Antacids, Multivitamins, or Dairy Products

The absorption of PYLERA may be reduced if administered with antacids containing aluminium, calcium, or magnesium; preparations containing iron, zinc, or sodium bicarbonate; or milk or dairy products due to the interaction between these products and tetracycline. These products should not be consumed concomitantly with PYLERA. However, the clinical significance of reduced tetracycline systemic exposure is unknown as the relative contribution of systemic versus local antimicrobial activity against Helicobacter pylori has not been established.

7.8 Busulfan

Metronidazole has been reported to increase plasma concentrations of busulfan, which can result in an increased risk for serious busulfan toxicity. Do not administer PYLERA concomitantly with busulfan unless the benefit outweighs the risk. If no therapeutic alternatives to PYLERA are available, and concomitant administration with busulfan is medically needed, monitor for busulfan toxicity and busulfan plasma concentrations and adjust the busulfan dose accordingly [see Warnings and Precautions (5.14)].

7.9 Inhibitors of CYP450 liver enzymes

The simultaneous administration of PYLERA and drugs that inhibit microsomal liver enzymes, such as cimetidine, may result in a prolonged half-life and decreased plasma clearance of metronidazole.

7.10 Inducers of CYP450 liver enzymes

The simultaneous administration of PYLERA and drugs that induce microsomal liver enzymes, such as phenytoin or phenobarbital, may accelerate the elimination of metronidazole, resulting in reduced plasma concentrations of metronidazole. Impaired clearance of phenytoin has also been reported in this situation. Monitor phenytoin concentrations during treatment with PYLERA.

Risk Summary

PYLERA is contraindicated in women who are pregnant because treatment of Helicobacter pylori infection can be delayed in pregnant women, and the use of drugs of the tetracycline class during the second and third trimester pregnancy can also cause permanent discoloration of the teeth (yellow-gray brown) and possibly inhibit bone development [see Warnings and Precautions (5.2) and Data]. Administration of oral tetracycline to pregnant rats at various doses resulted in yellow fluorescence in teeth and bones in the newborn animals. There are maternal risks with high intravenous doses of tetracycline [see Clinical Considerations].

Metronidazole usage in pregnancy has been associated with certain congenital anomalies [see Data]. In animals, no fetotoxicity was observed when metronidazole was orally administered to pregnant mice at approximately 5% of the indicated human dose. There are no human or animal data on the use of bismuth subcitrate potassium during pregnancy. Although there are data on the separate components, there are no available data on the use of PYLERA in pregnant women.

Clinical Considerations

Maternal Adverse Reactions

Tetracycline administered during pregnancy at high doses (>2 g IV) was associated with rare but serious cases of maternal hepatotoxicity. This syndrome may result in stillborn or premature birth due to maternal pathology [see Warnings and Precautions (5.3)].

Data

Human Data

Tetracycline:

Published case reports have described the yellowing of bones and teeth in human infants exposed to tetracycline during the second and third trimester of pregnancy. The yellowing is caused by the direct deposition of tetracycline during the mineralization process. This discoloration is more common during long-term use of the drug but has also been observed following repeated short-term courses. All tetracyclines form a stable calcium complex in any bone forming tissue. A decrease in fibula growth rate was observed in premature infants given oral tetracycline in doses of 25 mg/kg every six hours. The effect resolved when the drug was discontinued. One long-term follow-up study in children exposed to tetracycline in-utero showed no adverse effects on bone growth and development.

Metronidazole:

There are published data from case-control studies, cohort studies, and 2 meta-analyses that include more than 5000 pregnant women who used metronidazole during pregnancy. Many studies included first trimester exposures. One study showed an increased risk of cleft lip, with or without cleft palate, in infants exposed to metronidazole in-utero; however, these findings were not confirmed. In addition, more than ten randomized, placebo-controlled clinical trials enrolled more than 5000 pregnant women to assess the use of antibiotic treatment (including metronidazole) for bacterial vaginosis on the incidence of preterm delivery. Most studies did not show an increased risk for congenital anomalies or other adverse fetal outcomes following metronidazole exposure during pregnancy. Three studies conducted to assess the risk of infant cancer following metronidazole exposure during pregnancy did not show an increased risk; however, the ability of these studies to detect such a signal was limited.

Bismuth subcitrate potassium:

There are no human data on the use of bismuth subcitrate potassium during pregnancy.

Animal Data

Tetracycline:

Results of animal studies indicate that tetracycline crosses the placenta, is found in fetal tissues, and can have toxic effects on the developing fetus (often related to reversible retardation of skeletal development). Evidence of embryotoxicity has also been noted in animals treated early in pregnancy. Multiple studies of limited design were conducted with pregnant and lactating female rats that resulted in fetuses and neonates with yellow discoloration of bones and teeth.

Metronidazole:

Metronidazole crosses the placental barrier. No fetotoxicity was observed when metronidazole was administered orally to pregnant mice at 10 mg/kg/day, approximately 5 percent of the indicated human dose (1500 mg/day) based on body surface area; however in a single small study where the drug was administered intraperitoneally, some intrauterine deaths were observed. The relationship of these findings to the drug is unknown.

Bismuth subcitrate potassium:

Animal reproductive studies have not been conducted with bismuth subcitrate potassium.

Risk Summary

Two of the individual components of PYLERA, tetracycline and metronidazole, are present in human milk at concentrations similar to maternal serum levels. It is not known whether bismuth subcitrate, the third component of PYLERA is present in human milk. It is not known what effect metronidazole, tetracycline or bismuth has on the breastfed infant or on milk production. Tetracycline binds with calcium in human milk [see Clinical Pharmacology (12.3)]. Data indicate that oral absorption of tetracycline in infants is low due to the calcium binding in human milk. Metronidazole transfers to human milk, and infant serum levels can be close to or comparable to infant therapeutic levels. Because of the potential risk of tumorigenicity shown in animal studies with metronidazole, a woman should pump and discard human milk for the duration of PYLERA therapy, and for 2 days after therapy ends, and feed her infant stored human milk (collected prior to therapy) or formula.

Safety and effectiveness of PYLERA in pediatric patients infected with Helicobacter pylori have not been established.

Tetracycline use in children may cause permanent discoloration of the teeth. Enamel hypoplasia has also been reported. PYLERA should not be used in children up to 8 years of age [see Warnings and Precaution (5.4)].

Clinical studies of PYLERA did not include sufficient numbers of patients aged 65 and over to determine whether they respond differently than younger patients. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, elderly patients may have a greater frequency of decreased hepatic, renal, or cardiac function, and concomitant diseases or other drug therapies. Bismuth subcitrate potassium, a component of PYLERA, is known to be substantially excreted by the kidney, and the risk of adverse reactions may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, additional monitoring may be required [see Contraindications (4.5)].

The antianabolic action of the tetracyclines may cause an increase in blood urea nitrogen (BUN). In patients with severe renal impairment, higher serum concentrations of tetracycline may lead to azotemia, hyperphosphatemia, and acidosis [see Contraindications (4.5)].

Patients with severe hepatic disease metabolize metronidazole slowly, with resultant accumulation of metronidazole and its metabolites in plasma. Patients with mild to moderate hepatic impairment should be monitored for metronidazole associated adverse events. PYLERA is not recommended in patients with severe hepatic impairment [see Warnings and Precautions (5.10) and Clinical Pharmacology (12.3)].