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Drug Safety-related Labeling Changes (SrLC)

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FLAGYL (NDA-012623)

(METRONIDAZOLE)

Safety-related Labeling Changes Approved by FDA Center for Drug Evaluation and Research (CDER)

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10/06/2023 (SUPPL-70)

Approved Drug Label (PDF)

5 Warnings and Precautions

PRECAUTIONS

Nursing Mothers

Additions and/or revisions underlined:

Metronidazole is present in human milk at concentrations similar to maternal serum levels, and infant serum levels can be close to or comparable to infant therapeutic levels. There are no data on the effects of metronidazole on milk production. Animal studies have shown the potential for tumorigenicity after oral metronidazole was administered chronically to rats and mice (see PRECAUTIONS, Carcinogenesis, Mutagenesis, Impairment of Fertility). This drug is not intended to be administered chronically; therefore, the clinical relevance of the findings of the animal studies is unclear. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for FLAGYL and any potential adverse effects on the breastfed infant from FLAGYL or from the underlying maternal condition. Alternatively, a nursing mother may choose to pump and discard human milk for the duration of FLAGYL therapy, and for 48 hours after the last dose and feed her infant stored human milk or formula.

12/15/2021 (SUPPL-69)

Approved Drug Label (PDF)

4 Contraindications

Additions and/or revisions underlined

Cockayne Syndrome

FLAGYL Tablets are contraindicated in patients with Cockayne syndrome. Severe irreversible hepatotoxicity/acute liver failure with fatal outcomes have been reported after initiation of metronidazole in patients with Cockayne syndrome (see ADVERSE REACTIONS).

6 Adverse Reactions

Additions underlined

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).

03/05/2021 (SUPPL-68)

Approved Drug Label (PDF)

5 Warnings and Precautions

PRECAUTIONS

Additions underlined

Drug Interactions

Drugs that Prolong the QT interval

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

6 Adverse Reactions

 

Additions underlined

Cardiovascular: QT prolongation has been reported, particularly when metronidazole was administered with drugs with the potential for prolonging the QT interval. Flattening of the T-wave may be seen in electrocardiographic tracings.

04/03/2018 (SUPPL-67)

Approved Drug Label (PDF)

5 Warnings and Precautions

WARNINGS

(Newly added subsection)

Risk of Hepatotoxicity and Death in Patients with Cockayne Syndrome

Cases of severe hepatotoxicity/acute hepatic failure, including cases with a fatal outcome with very rapid onset after treatment initiation in patients with Cockayne syndrome have been reported with products containing metronidazole for systemic use. In this population, metronidazole should therefore be used after careful benefit-risk assessment and only if no alternative treatment is available. Obtain liver function tests prior to the start of therapy, within the first 2-3 days after initiation of therapy, frequently during therapy and after end of treatment. Discontinue metronidazole if elevation of liver function tests occurs, and monitor liver function tests until the baseline values are reached.

Advise patients with Cockayne syndrome to stop taking metronidazole immediately if they experience any symptoms of potential liver injury, such as abdominal pain, nausea, change in stool color or jaundice, and to contact their healthcare provider.