Fosfomycin Disodium

FDA Drug Information • Also known as: Contepo

Brand Names: Contepo
Route: INTRAVENOUS
Dosage Form: INJECTION, POWDER, FOR SOLUTION
Product Type: HUMAN PRESCRIPTION DRUG

Description

11 DESCRIPTION CONTEPO (fosfomycin) for injection, for intravenous use, contains fosfomycin disodium, an epoxide antibacterial drug. Fosfomycin disodium is a powder with the chemical name of disodium [(2R,3S)-3-methyloxiran-2-yl]-dioxido-oxophosphorane, an empirical formula of C 3 H 5 Na 2 O 4 P and molecular weight of 182. Figure 1 Chemical Structure of Fosfomycin Disodium Each CONTEPO for Injection single-dose vial contains white to almost white sterile powder with 6 grams of fosfomycin (equivalent to 7.9 grams fosfomycin disodium) and the inactive ingredient succinic acid (150 mg) for pH adjustment. It is intended for constitution and further dilution prior to intravenous infusion . Each gram of fosfomycin disodium contains 330 mg of sodium (i.e., each vial contains 1,980 mg of sodium). Figure 1

What Is Fosfomycin Disodium Used For?

1 INDICATIONS AND USAGE CONTEPO is an epoxide antibacterial indicated for the treatment of patients 18 years of age and older with complicated urinary tract infections (cUTI) including acute pyelonephritis caused by susceptible isolates of Escherichia coli and Klebsiella pneumoniae . ( 1.1 ) Usage to Reduce Development of Drug-Resistant Bacteria To reduce the development of drug-resistant bacteria and maintain the effectiveness of CONTEPO and other antibacterial drugs, CONTEPO should be used only to treat infections that are proven or strongly suspected to be caused by bacteria. ( 1.2 ) 1.1 Complicated Urinary Tract Infections (cUTI), including Acute Pyelonephritis CONTEPO is indicated for the treatment of patients 18 years and older with complicated urinary tract infections (cUTI), including acute pyelonephritis, caused by susceptible isolates of Escherichia coli and Klebsiella pneumoniae . 1.2 Usage to Reduce Development of Drug-Resistant Bacteria To reduce the development of drug-resistant bacteria and maintain the effectiveness of CONTEPO and other antibacterial drugs, CONTEPO should be used only to treat infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

Dosage and Administration

2 DOSAGE AND ADMINISTRATION Administer CONTEPO, 6 grams every 8 hours by intravenous (IV) infusion over 1 hour for up to 14 days, in patients 18 years of age or older with an estimated creatinine clearance (CLcr) greater than 50 mL/min. ( 2.1 ) The recommended dosage in patients 18 years of age and older with an estimated CLcr of 50 mL/min or less is presented in the table below. ( 2.2 ) a CLcr estimated using Cockcroft-Gault Equation. b All doses of CONTEPO are administered by intravenous infusion over 1 hour. Estimated CLcr (mL/min) a Loading Dose b Maintenance Dosage b Dose Frequency 41-50 6 grams 4 grams Every 8 hours 31-40 6 grams 3 grams Every 8 hours 21-30 6 grams 5 grams Every 24 hours 11-20 6 grams 3 grams Every 24 hours Approximately 60% to 80% of the fosfomycin dose is cleared from the body by hemodialysis. Administer CONTEPO after hemodialysis on hemodialysis days. ( 2.2 ) 2.1 Recommended Dosage The recommended dosage of CONTEPO is 6 grams administered every 8 hours by intravenous (IV) infusion over 1 hour in patients 18 years of age or older with an estimated creatinine clearance (CLcr) greater than 50 mL/min. The duration of therapy is up to 14 days and should be guided by the severity of infection and the patient's clinical status. During treatment, different dosage recommendations may be required based on change in estimated CLcr [ see Dosage and Administration ( 2.2 ) ] . 2.2 Recommended Dosage in Patients (18 Years of Age and Older) with Renal Impairment The recommended dosage of CONTEPO in patients 18 years of age and older with an estimated CLcr of 50 mL/min or less is presented in Table 1 . Monitor estimated CLcr and adjust the dosage of CONTEPO accordingly [ see Warnings and Precautions ( 5.1 ), Use in Specific Populations ( 8.6 ) and Clinical Pharmacology ( 12.3 ) ] . Table 1 Dosage of CONTEPO in Patients (18 Years of Age and Older) with Renal Impairment a CLcr estimated by Cockcroft-Gault Equation. b All doses of CONTEPO are administered by IV infusion over 1 hour. Estimated CLcr (mL/min) a Loading Dose b Maintenance Dosage b Dose Frequency 41-50 6 grams 4 grams Every 8 hours 31-40 6 grams 3 grams Every 8 hours 21-30 6 grams 5 grams Every 24 hours 11-20 6 grams 3 grams Every 24 hours Approximately 60 to 80 % of the fosfomycin dose is cleared from the body by hemodialysis. Administer CONTEPO after hemodialysis on hemodialysis days. 2.3 Preparation of Diluted Solutions of CONTEPO Preparation CONTEPO is supplied as a dry powder in a single-dose vial that must be constituted and further diluted prior to intravenous infusion as described below. CONTEPO does not contain preservatives. Aseptic technique must be used for constitution and dilution prior to IV infusion. Constitute the vial with 30 mL of Sterile Water for Injection, USP and gently mix to completely dissolve contents. A slight degree of warming occurs when the powder is dissolved. The constituted solution should appear clear and colorless. Parenteral drug products...

Side Effects (Adverse Reactions)

6 ADVERSE REACTIONS The following adverse reactions are discussed in greater detail in the Warnings and Precautions section: Serum Electrolyte Abnormalities [see Warnings and Precautions ( 5.1 )] QT Prolongation [see Warnings and Precautions ( 5.2 )] Increased Transaminase Levels [see Warnings and Precautions ( 5.3 )] Hypersensitivity Reactions [see Warnings and Precautions ( 5.4 )] Neutropenia Including Agranulocytosis [see Warnings and Precautions ( 5.5 )] Clostridioides difficile -Associated Diarrhea [see Warnings and Precautions ( 5.6 )] Development of Drug-Resistant Bacteria [see Warnings and Precautions ( 5.7 )] Most common adverse reactions (incidence ≥2%) are transaminase elevations, hypokalemia, neutropenia, nausea, vomiting, diarrhea, hypocalcemia, hypernatremia, headache, and hypophosphatemia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Meitheal Pharmaceuticals Inc. at 1-844-824-8426 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. CONTEPO was evaluated in a comparator-controlled clinical trial (Trial 1) in patients with cUTI, including acute pyelonephritis, which included 233 patients treated with CONTEPO and 231 treated with comparator (piperacillin/tazobactam 4.5 g every 8 hours) for 7 days, allowing bacteremic patients to receive up to 14 days. No switch to oral antibacterial drugs was allowed. The median age of treated patients was 54 years (range 18-89 years) and 64% were female. All patients were white (100%). Patients (99%) were predominantly enrolled in Eastern Europe. Concomitant bacteremia was identified in 9% of patients at baseline. Serious Adverse Reactions and Adverse Reactions Leading to Discontinuation Serious adverse reactions occurred in 2.1% (5/233) CONTEPO and 2.6% (6/231) piperacillin/tazobactam-treated patients, respectively. Treatment was discontinued due to adverse reactions in 3% (7/233) of patients receiving CONTEPO and in 2.6% (7/231) of patients receiving piperacillin/tazobactam. The most common adverse reactions resulting in discontinuation of CONTEPO were gastrointestinal disorders (nausea, vomiting, and abdominal pain) in 1.3% (3/233) of patients. No deaths occurred in the clinical trial. Common Adverse Reactions Table 3 lists adverse reactions occurring in 2% or greater of patients receiving CONTEPO in Trial 1. These adverse reactions were reversible upon completion of therapy. Table 3 Adverse Reactions Occurring in 2% or Greater of Patients with cUTI Receiving CONTEPO in Trial 1 a Transaminase elevations include increased ALT and AST ≥3x ULN. b Neutropenia includes absolute neutrophil count <1500 cells/mm 3 Adverse Reaction CONTEPO N=233 % Piperacillin/Tazobactam N=231 % Gastrointestinal Disorders Nausea 4.3 1.3 Diarrhea 3.9 4.8 Vomiting 3.9 0.4 Laboratory Investigations Transaminase elevations a 10.3 4.8 Hypokalemia 9.9 1.7 Hypophosphatemia 2.1 0.0 Hypocalcemia 3.9 2.6 Hypernatremia 3.4 0.9 Blood and Lymphatic System Disorders Neutropenia b 6.4 3.9 Nervous System Disorders Headache 2.6 2.2 Adverse Reactions Occurring in < 2% of Patients Receiving CONTEPO in Trial 1: Blood and lymphatic system disorders : anemia, thrombocytopenia Cardiac disorders : atrial fibrillation, palpitations, tachycardia, heart failure Ear and labyrinth disorders : hearing loss Gastrointestinal disorders : constipation General disorders and administration site conditions : asthenia, infusion site reactions, peripheral edema Hepatobiliary disorders : hepatic steatosis, hepatomegaly Infections and infestations : vaginal infection, vaginitis Investigations : increase creatinine kinase Metabolism and nutritional disorders : hyperglycemia Nervous system disorders : dysgeusia, syncope Respiratory, thoracic, and...

Drug Interactions

7 DRUG INTERACTIONS Avoid co-administration of CONTEPO with drugs known to prolong the QT interval. ( 5.2 , 7.1 ) 7.1 Drugs that prolong QT interval Co-administration of CONTEPO with other drugs known to prolong the QT interval may increase the risk for ventricular arrhythmia. Avoid co-administration of CONTEPO with drugs known to prolong the QT interval, such as class IA or class III antiarrhythmic medications, tricyclic antidepressants, macrolides, and antipsychotics [see Warnings and Precautions ( 5.2 )] .

Contraindications

4 CONTRAINDICATIONS CONTEPO is contraindicated in patients with known serious hypersensitivity to fosfomycin, or any of the excipients [ see Warnings and Precautions ( 5.2 ) ] . CONTEPO is contraindicated in patients with known serious hypersensitivity to fosfomycin, or any of the excipients. ( 4 )

Pregnancy and Breastfeeding

8.1 Pregnancy Risk Summary Available data from observational studies and pharmacovigilance reports with fosfomycin use in pregnant women are insufficient to identify a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. Fosfomycin crosses the placental barrier. There are no animal data that meet current standards for nonclinical developmental toxicity studies. However, some reproductive toxicity data are available from published literature. Intravenous or intraperitoneal fosfomycin-sodium did not cause malformations in rabbits or rats, respectively, but showed evidence of fetotoxicity (see Data ). The clinical relevance of these animal data is uncertain. The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defect and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Animal Data Fosfomycin crosses the placenta in rats and rabbits. In rats administered intraperitoneal fosfomycin sodium on Days 7 to 17 of gestation (during organogenesis), there were increased numbers of dead or resorbed fetuses at 1500 mg/kg (approximately 0.8 times the recommended human dose of 18 g/day, based on body surface area comparisons), a dose associated with maternal toxicity . Rabbits were administered intravenous fosfomycin sodium on Days 6 to 18 of gestation (during organogenesis) at doses 800 mg/kg (approximately 0.9 times the recommended human dose). No malformations were observed in rabbits or rats after intravenous or intraperitoneal fosfomycin sodium, respectively. In a pre- and post-natal developmental study in rats (dosed intraperitoneally with fosfomycin tromethamine between gestational day 6 and postnatal Day 21), no effects were observed in first-generation offspring at doses up to...

Overdosage

10 OVERDOSAGE To date, no cases of accidental overdose with clinically relevant intolerances have been reported. In the event of an overdose, the patient must be monitored and treated symptomatically. Fosfomycin is cleared from the body by hemodialysis, during which patients with end stage renal disease have an increased mean fosfomycin elimination half-life to approximately 4 hours.

How Supplied

16 HOW SUPPLIED/STORAGE AND HANDLING How Supplied CONTEPO for injection is supplied as a white to almost white sterile powder containing 6 grams of fosfomycin in a single-dose vial. Each gram of fosfomycin disodium contains 330 mg of sodium (i.e., each vial contains 1,980 mg of sodium). CONTEPO is supplied in a clear Type I glass single-dose vial (NDC 71288-035-51) with a rubber closure and a twist-off cap. Twelve ( 12 ) vials are supplied in each carton (NDC 71288-035-52). Storage and Handling Store CONTEPO vials at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) [See USP Controlled Room Temperature]. Store CONTEPO in the carton until time of use [see Dosage and Administration ( 2.4 )].

About This Information

This drug information is sourced from FDA-approved labeling via the openFDA database. It is intended for educational and reference purposes only. This is not medical advice. Always consult your healthcare provider before making decisions about medication. Drug information may be updated by the FDA; check with your pharmacist for the most current information.

What are side effects?

Side effects are unwanted reactions that can occur when taking a medication. They range from mild (headache, nausea) to severe (allergic reactions, organ damage). Not everyone experiences side effects, and severity varies. Report any concerning side effects to your doctor.

What are drug interactions?

Drug interactions occur when a medication is affected by another drug, food, or supplement. Interactions can make medications less effective or cause dangerous side effects. Always tell your doctor about all medications and supplements you take.