1 INDICATIONS AND USAGE Methylene blue injection is indicated for the treatment of pediatric and adult patients with acquired methemoglobinemia.

Methylene blue is an oxidation-reduction agent indicated for the treatment of pediatric and adult patients with acquired methemoglobinemia.

6 ADVERSE REACTIONS The following adverse reactions are discussed in greater detail in other sections of the labeling: Serotonin Syndrome with Concomitant Use of Serotonergic Drugs [see Warnings and Precautions ( 5.1 )] Anaphylaxis [see Warnings and Precautions ( 5.2 )] Lack of Effectiveness [see Warnings and Precautions ( 5.3 )] Hemolytic Anemia [see Warnings and Precautions ( 5.4 )] Interference with In-Vivo Monitoring Devices [see Warnings and Precautions ( 5.5 )] Effects on Ability to Drive and Operate Machinery [see Warnings and Precautions ( 5.6 )] Interference with Laboratory Tests [see Warnings and Precautions ( 5.7 )] The most commonly reported adverse reactions (≥2%) included headache, hypokalemia, diarrhea, hypomagnesemia, myoclonus, nausea, and seizure-like phenomena.

( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Zydus Pharmaceuticals (USA) Inc.

at 1-877-993-8779 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

6.1 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 safety of methylene blue injection in adults with acquired methemoglobinemia was assessed in 24 patients who received at least 1 dose of methylene blue injection [see Clinical Studies (14)] .

Most doses administered were 1 mg/kg (88.5%), but doses from 1 mg/kg to 2 mg/kg were administered.

All patients received at least one dose of methylene blue injection; two received two doses.

Serious adverse reactions occurred in 4.2% of patients who received methylene blue injection.

A serious adverse reaction of seizure-like phenomenon was reported in one patient.

Adverse reactions (≥2%) included headache, hypokalemia, diarrhea, hypomagnesemia, myoclonus, nausea, and seizure-like phenomena.

The safety of methylene blue injection in pediatric patients with acquired methemoglobinemia was assessed in two retrospective case series that included two pediatric patients treated with methylene blue injection and 12 treated with another methylene blue product.

The case series included patients in the following age groups: 3 neonates (<1 month), 4 infants (1 month to <2 years), 4 children (2 years to <12 years), and 3 adolescents (12 years to <17 years).

The safety profile in pediatric patients was similar to that in adult patients.

Other adverse reactions reported to occur following the administration of methylene blue class products include the following: Blood and lymphatic system disorders : hemolytic anemia, hemolysis, hyperbilirubinemia Cardiac disorders : palpitations, tachycardia Eye disorders : eye pruritus, ocular hyperemia, vision blurred Gastrointestinal disorders : abdominal pain lower, dry mouth, flatulence, glossodynia, tongue eruption General disorders and administration site conditions : death, infusion site extravasation, infusion site induration, infusion site pruritus, infusion site swelling, infusion site urticaria, peripheral swelling, thirst Investigations : elevated liver enzymes Musculoskeletal and connective tissue disorders : myalgia Renal and urinary disorders : dysuria Respiratory, thoracic and mediastinal disorders : nasal congestion, oropharyngeal pain, rhinorrhea, sneezing Skin and subcutaneous tissue disorders : necrotic ulcer, papule, phototoxicity Vascular disorders : hypertension