CEFTRIAXONE — ceftriaxone sodium injection, powder, for solution
Wockhardt USA LLC.
To reduce the development of drug-resistant bacteria and maintain the effectiveness of ceftriaxone for injection and other antibacterial drugs, ceftriaxone for injection should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria.
Ceftriaxone for injection, USP is a sterile, semisynthetic, broad-spectrum cephalosporin antibiotic for intravenous or intramuscular administration. Ceftriaxone sodium is (6R ,7R)-7-[2-(2-Amino-4-thiazolyl)glyoxylamido]-8-oxo-3-[[(1,2,5,6-tetrahydro-2-methyl-5,6-dioxo-as -triazin-3-yl)thio]methyl]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, 72 -(Z)-(O -methyloxime), disodium salt, sesquaterhydrate.
The chemical formula of ceftriaxone sodium is C18 H16 N8 Na2 O7 S3 ●3.5H2 O. It has a calculated molecular weight of 661.59 and the following structural formula:
Ceftriaxone for injection, USP is a white to yellowish-orange crystalline powder which is readily soluble in water, sparingly soluble in methanol and very slightly soluble in ethanol. The pH of a 1% aqueous solution is approximately 6.7. The color of ceftriaxone for injection, USP solutions ranges from light yellow to amber, depending on the length of storage, concentration and diluent used.
Ceftriaxone for injection, USP contains approximately 83 mg (3.6 mEq) of sodium per gram of ceftriaxone activity.
Average plasma concentrations of ceftriaxone following a single 30-minute intravenous (IV) infusion of a 0.5, 1 or 2 g dose and intramuscular (IM) administration of a single 0.5 (250 mg/mL or 350 mg/mL concentrations) or 1 g dose in healthy subjects are presented in Table 1.
* IV doses were infused at a constant rate over 30 minutes.
ND = Not determined.
|Dose/Route||Average Plasma Concentrations (mcg/mL)|
|0.5 hr||1 hr||2 hr||4 hr||6 hr||8 hr||12 hr||16 hr||24 hr|
|0.5 g IV*||82||59||48||37||29||23||15||10||5|
|0.5 g IM 250 mg/mL||22||33||38||35||30||26||16||ND||5|
|0.5 g IM 350 mg/mL||20||32||38||34||31||24||16||ND||5|
|1 g IV*||151||111||88||67||53||43||28||18||9|
|1 g IM||40||68||76||68||56||44||29||ND||ND|
|2 g IV*||257||192||154||117||89||74||46||31||15|
Ceftriaxone was completely absorbed following IM administration with mean maximum plasma concentrations occurring between 2 and 3 hours post-dose. Multiple IV or IM doses ranging from 0.5 to 2 g at 12- to 24-hour intervals resulted in 15% to 36% accumulation of ceftriaxone above single dose values.
Ceftriaxone concentrations in urine are shown in Table 2.
ND = Not determined.
|Dose/Route||Average Urinary Concentrations (mcg/mL)|
|0 to 2 hr||2 to 4 hr||4 to 8 hr||8 to 12 hr||12 to 24 hr||24 to 48 hr|
|0.5 g IV||526||366||142||87||70||15|
|0.5 g IM||115||425||308||127||96||28|
|1 g IV||995||855||293||147||132||32|
|1 g IM||504||628||418||237||ND||ND|
|2 g IV||2692||1976||757||274||198||40|
Thirty-three percent to 67% of a ceftriaxone dose was excreted in the urine as unchanged drug and the remainder was secreted in the bile and ultimately found in the feces as microbiologically inactive compounds. After a 1 g IV dose, average concentrations of ceftriaxone, determined from 1 to 3 hours after dosing, were 581 mcg/mL in the gallbladder bile, 788 mcg/mL in the common duct bile, 898 mcg/mL in the cystic duct bile, 78.2 mcg/g in the gallbladder wall and 62.1 mcg/mL in the concurrent plasma.
Over a 0.15 to 3 g dose range in healthy adult subjects, the values of elimination half-life ranged from 5.8 to 8.7 hours; apparent volume of distribution from 5.78 to 13.5 L; plasma clearance from 0.58 to 1.45 L/hour; and renal clearance from 0.32 to 0.73 L/hour. Ceftriaxone is reversibly bound to human plasma proteins, and the binding decreased from a value of 95% bound at plasma concentrations of <25 mcg/mL to a value of 85% bound at 300 mcg/mL. Ceftriaxone crosses the blood placenta barrier.
The average values of maximum plasma concentration, elimination half-life, plasma clearance and volume of distribution after a 50 mg/kg IV dose and after a 75 mg/kg IV dose in pediatric patients suffering from bacterial meningitis are shown in Table 3. Ceftriaxone penetrated the inflamed meninges of infants and pediatric patients; CSF concentrations after a 50 mg/kg IV dose and after a 75 mg/kg IV dose are also shown in Table 3.
|50 mg/kg IV||75 mg/kg IV|
|Maximum Plasma Concentrations (mcg/mL)||216||275|
|Elimination Half-life (hr)||4.6||4.3|
|Plasma Clearance (mL/hr/kg)||49||60|
|Volume of Distribution (mL/kg)||338||373|
|CSF Concentration-inflamed meninges (mcg/mL)||5.6||6.4|
|Range (mcg/mL)||1.3 to 18.5||1.3 to 44|
|Time after dose (hr)||3.7 (±1.6)||3.3 (±1.4)|
Compared to that in healthy adult subjects, the pharmacokinetics of ceftriaxone were only minimally altered in elderly subjects and in patients with renal impairment or hepatic dysfunction (Table 4); therefore, dosage adjustments are not necessary for these patients with ceftriaxone dosages up to 2 g per day. Ceftriaxone was not removed to any significant extent from the plasma by hemodialysis; in six of 26 dialysis patients, the elimination rate of ceftriaxone was markedly reduced.
|Subject Group||Elimination Half-Life (hr)||Plasma Clearance (L/hr)||Volume of Distribution (L)|
|Healthy Subjects||5.8 to 8.7||0.58 to 1.45||5.8 to 13.5|
|Elderly Subjects (mean age, 70.5 yr)||8.9||0.83||10.7|
|Patients With Renal Impairment|
|Hemodialysis Patients (0 to 5 mL/min)*||14.7||0.65||13.7|
|Severe (5 to 15 mL/min)||15.7||0.56||12.5|
|Moderate (16 to 30 mL/min)||11.4||0.72||11.8|
|Mild (31 to 60 mL/min)||12.4||0.70||13.3|
|Patients With Liver Disease||8.8||1.1||13.6|
Pharmacokinetics in the Middle Ear Fluid: In one study, total ceftriaxone concentrations (bound and unbound) were measured in middle ear fluid obtained during the insertion of tympanostomy tubes in 42 pediatric patients with otitis media. Sampling times were from 1 to 50 hours after a single intramuscular injection of 50 mg/kg of ceftriaxone. Mean (± SD) ceftriaxone levels in the middle ear reached a peak of 35 (± 12) mcg/mL at 24 hours, and remained at 19 (± 7) mcg/mL at 48 hours. Based on middle ear fluid ceftriaxone concentrations in the 23 to 25 hour and the 46 to 50 hour sampling time intervals, a half-life of 25 hours was calculated. Ceftriaxone is highly bound to plasma proteins. The extent of binding to proteins in the middle ear fluid is unknown.
Interaction with Calcium: Two in vitro studies, one using adult plasma and the other neonatal plasma from umbilical cord blood have been carried out to assess interaction of ceftriaxone and calcium. Ceftriaxone concentrations up to 1 mM (in excess of concentrations achieved in vivo following administration of 2 grams ceftriaxone infused over 30 minutes) were used in combination with calcium concentrations up to 12 mM (48 mg/dL). Recovery of ceftriaxone from plasma was reduced with calcium concentrations of 6 mM (24 mg/dL) or higher in adult plasma or 4 mM (16 mg/dL) or higher in neonatal plasma. This may be reflective of ceftriaxone-calcium precipitation.
Mechanism of Action
Ceftriaxone is a bactericidal agent that acts by inhibition of bacterial cell wall synthesis. Ceftriaxone has activity in the presence of some beta-lactamases, both penicillinases and cephalosporinases, of Gram-negative and Gram-positive bacteria.
Mechanism of Resistance
Resistance to ceftriaxone is primarily through hydrolysis by beta-lactamase, alteration of penicillin-binding proteins (PBPs), and decreased permeability.
Interaction with Other Antimicrobials
In an in vitro study antagonistic effects have been observed with the combination of chloramphenicol and ceftriaxone.
Ceftriaxone has been shown to be active against most isolates of the following bacteria, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE (1) section:
● Gram-negative bacteria
● Gram-positive bacteria
Viridans group streptococci
● Anaerobic bacteria
The following in vitro data are available, but their clinical significance is unknown. At least 90 percent of the following microorganisms exhibit an in vitro minimum inhibitory concentration (MIC) less than or equal to the susceptible breakpoint for ceftriaxone. However, the efficacy of ceftriaxone in treating clinical infections due to these microorganisms has not been established in adequate and well-controlled clinical trials.
● Gram-negative bacteria
Providencia species (including Providencia rettgeri)
Salmonella species (including Salmonella typhi)
● Gram-positive bacteria:
● Anaerobic bacteria:
Porphyromonas (Bacteroides) melaninogenicus
Prevotella (Bacteroides) bivius
Susceptibility Test Methods
For specific information regarding susceptibility test interpretive criteria and associated test methods and quality control standards recognized by FDA for this drug, please see: https://www.fda.gov/STIC.
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