quinupristin/dalfopristin

Action and Spectrum

Action and Spectrum: 

Action:  

quinupristin/dalfopristin interferes with bacterial protein synthesis by binding to the ribosome and preventing the formation of peptide bonds. This leads to the inhibition of bacterial growth and replication. 

Spectrum:  

quinupristin/dalfopristin is active against a wide range of gram-positive bacteria, including VRE, Streptococcus pneumoniae, Streptococcus pyogenes, and Staphylococcus aureus. It is not active against gram-negative bacteria. 

Drug Interaction

Adverse Reaction

Frequency defined 

>10% 

Inflammation at infusion site (38-42%) 

Local pain (40-44%) 

Hyperbilirubinemia (3-35%) 

Infusion site reaction (12-13%) 

Local edema (17-18%) 

1-10% 

Myalgia (<1-5%) 

Nausea (3-5%) 

Arthralgia (<1-8%) 

Vomiting (3% to 4%) 

Diarrhea (3%) 

Anemia (3%) 

incr LDH (3%) 

Pain (2-3%) 

Rash (3%) 

Black Box Warning

Black Box Warning: 

quinupristin/dalfopristin (trade name Synercid) is a combination of two antibiotics used to treat serious bacterial infections caused by gram-positive bacteria. The drug has a black box warning due to its potential for causing serious and sometimes fatal heart problems, such as irregular heartbeats, that can lead to cardiac arrest. 

Contraindication / Caution

Contraindication / Caution: 

Contraindications: 

• Hypersensitivity to quinupristin, dalfopristin, or any of the excipients used in the formulation. 
• History of Long QT syndrome or any condition that predisposes to prolongation of the QT interval. 

Cautions: 

• Patients with renal impairment should be closely monitored as the drug is mainly excreted through the kidneys. Dosage adjustment may be necessary. 
• Patients with liver disease should be closely monitored as the drug is metabolized by the liver. 
• Patients with history of myocardial infarction or other heart disease should be closely monitored as the drug may cause arrhythmias. 
• Patients with a history of resistant or difficult-to-treat infections should be closely monitored for the development of resistant bacteria or fungi during treatment. 
• The combination of quinupristin/dalfopristin with other antibiotics, particularly those known to cause arrhythmias, should be avoided. 
• Patients receiving quinupristin/dalfopristin should be closely monitored for signs of gastrointestinal intolerance, such as abdominal pain, nausea, and vomiting. 
• Pregnant women and women who are breastfeeding should only be treated with quinupristin/dalfopristin if the potential benefit to the mother outweighs the potential risk to the fetus or newborn. 

Pregnancy / Lactation

Pregnancy warnings:     

US FDA pregnancy category: B 

Lactation:   

Excreted into human milk is unknown  

Pregnancy Categories:         

Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester.    

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women.   

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.     

Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.     

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.     

Category N: There is no data available for the drug under this category 

Pharmacology

Pharmacology: 

Quinupristin/dalfopristin is a combination of two streptogramin antibiotics used to treat serious infections caused by certain bacteria. 

Pharmacodynamics: 

Mechanism of Action: The combination of quinupristin and dalfopristin acts by inhibiting bacterial protein synthesis. Quinupristin targets the 50S ribosomal subunit, while dalfopristin targets the 30S ribosomal subunit. By binding to both subunits, the antibiotics prevent bacterial growth and replication. 

Pharmacokinetics: 

Absorption 

quinupristin/dalfopristin is administered intravenously and is rapidly absorbed into the bloodstream. 

Distribution 

The drug has a moderate volume of distribution and is distributed in the extracellular fluid. 

Metabolism 

quinupristin/dalfopristin is not metabolized and is excreted unchanged in the urine. 

Elimination and excretion 

The elimination half-life of quinupristin/dalfopristin is approximately 2 hours. The drug is eliminated primarily by the kidneys. 

Adminstartion

Administration:

quinupristin/dalfopristin is a combination antibiotic used to treat infections caused by gram-positive bacteria. It is available as a powder for intravenous infusion and is administered by healthcare professionals in a hospital setting. The recommended dosage and duration of treatment depends on the severity of the infection, the type of bacteria causing the infection, and the patient’s overall health. The usual adult dose is 7.5 mg/kg every 8 hours, administered as an intravenous infusion over 30 minutes to 1 hour. It is important to monitor patients for any adverse reactions, including hypersensitivity reactions, during treatment with quinupristin/dalfopristin. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: quinupristin/dalfopristin 

Why do we use quinupristin/dalfopristin? 

quinupristin/dalfopristin is used to treat serious infections caused by certain types of gram-positive bacteria that are resistant to other antibiotics. This combination antibiotic works by blocking the bacterial cell wall synthesis and protein synthesis, leading to bacterial death. It is particularly effective against strains of bacteria that have developed resistance to other antibiotics, such as methicillin-resistant Staphylococcus aureus (MRSA) and Streptococcus pneumoniae.