Doripenem

Absorption

Doripenem is administered intravenously as an infusion. There was no accumulation of doripenem following mulitiple infusions of either 500mg or 1g administered every 8 hours for 7-10 days in subjects with normal renal function.

Toxicity

Dosage adjustment is necessary in patients with moderate and severe renal impairment.
Doripenem's FDA label includes a warning against use in ventilator-associated bacterial pneumonia, as a clinical trial for that indication resulted in increased mortality with doripenem (23% vs. 16.7% recieving imipenem) as well as lower clinical response rates.
Seizures have been reported with doripenem treatment; patients at greater risk of developing seizures we found to have pre-existing central nervous system (CNS) conditions, compromised renal function, or patients receiving higher doses than 500 mg every 8 hours. Doripenem also reduces plasma levels of valproic acid when administered concomitantly; therefore patients with pre-existing seizure disorders on valproic acid are at even higher risk of breakthrough seizures if receiving both drugs at the same time.
Doripenem is considered pregnancy category B as it was not found to be teratogenic or produce effects on ossification, developmental delays, or fetal weight in rat and rabbit studies. There are no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. It is not known whether doripenem is excreted into breast milk, therefore caution should be exercised with doripenem administration to nursing women.

Description

Doripenem monohydrate is an ultra-broad-spectrum injectable β-lactam antibiotic and belongs to the subgroup of carbapenems. It was introduced by Shionogi Co. of Japan under the brand name Finibax in 2005 and is being marketed outside Japan by Johnson & Johnson. Doripenem act by decreases the process of cell wall growth, which eventually leads to elimination of the infectious cell bacteria together. It is used for treatment of bacterial respiratory and urinary tract infections. Doripenem is a 1β-methyl carbapenem derivative, and it is the fourth analog to be marketed in this series following the launch of meropenem, biapenem, and ertapenem in previous years. The introduction of a 1β-methyl group to the carbapenem skeleton enhances metabolic stability to renal dehydropeptidase-1 (DHP-1) and leads to improved antibacterial potency.

The Uses of Doripenem

Doripenem hydrate is used to treat complicated urinary infection including Pyelonephritis caused by E.coli. Doripenem hydrate is promoted in the United States as DORIBAX(R). This drug is synthesized from p-nitrobenzyl-protected enolphosphate 2b and N-(p-nitrobenzyloxycarbonyl)-protected aminomethylpyrrolidine.

Indications

Doripenem is indicated in the treatment of complicated intra-abdominal infections and complicated urinary tract infections, including pyelonephritis, caused by designated susceptible bacteria.

Background

Doripenem is a broad-spectrum, carbapenem antibiotic marketed under the brand name Doribax by Janssen. Doripenem injection was approved by the FDA in 2007 to treat complicated urinary tract and intra-abdominal infections. In a clinical trial of doripenem treatment in ventilator associated pneumonia (vs. imipenem and cilastatin), it was found that doripenem carried an increased risk of death and lower clinical cure rates, resulting in a premature termination of the trial. The FDA revised the doripenem label in 2014 to include a warning against use in ventilator-associated pneumonia and to reiterate its safety and efficacy for its approved indications.

What are the applications of Application

Doripenem is an antibacterial agent

Pharmacokinetics

Similar to other beta-lactam antimicrobial agents, the time that unbound plasma concentration of doripenem exceeds the MIC (T>MIC) of the infecting organism has been shown to best correlate with efficacy in animal models of infection.

Metabolism

Metabolism of doripenem is via dehydropeptidase-I (also called dipeptidase-1) into a microbiologically inactive ring-opened metabolite, doripenem-M1. Doripenem does not appear to be a substrate of the hepatic CYP450 enzymes.