Oritavancin (Orbactiv) - Uses, Doses, MOA, Side effects

Oritavancin (Orbactiv) is a new-generation synthetic lipoglycopeptide that is used as a single injection for the treatment of acute bacterial skin and soft-tissue infections.

Oritavancin Uses:

  • Acute bacterial skin and skin structure infections:

    • Adult patients with acute bacterial skin and skin structure infections (ABSSSI) brought on by susceptible isolates of the gram-positive pathogens listed below are treated with it.:
      • Staphylococcus aureus (including methicillin-susceptible and methicillin-resistant isolates)
      • Streptococcus pyogenes
      • Streptococcus agalactiae
      • Streptococcus dysgalactiae, Streptococcus anginosus group (including S. anginosus, S. intermedius, S. constellatus)
      • Enterococcus faecalis (vancomycin-susceptible isolates only)

Oritavancin (Orbactiv) Dose in Adults

Oritavancin (Orbactiv) Dose in the treatment of Acute bacterial skin and skin structure infections (ABSSI):

  • IV: 1,200 mg as a stat dose.

Use in Children:

Not studied in children.

Pregnancy Risk Factor C

  • In animal reproduction studies, no adverse events were observed.

Use during breastfeeding:

  • It is unknown if the drug is excreted from breast milk.
  • It is recommended that nursing women be cautious when administering the medication.

Dose in Kidney Disease:

  • CrCl ≥30 mL/minute:

    • Dosage adjustment not necessary.
  • CrCl <30 mL/minute:

    • No dosage adjustments have been provided in the manufacturer’s labeling (has not been studied).
  • ESRD requiring hemodialysis:

    • No dosage adjustments have been provided in the manufacturer’s labeling (has not been studied)
    • It is not removed by hemodialysis.

Dose in Liver Disease:

  • Mild to moderate hepatic impairment (Child-Pugh class A or B):

    • No Dosage adjustment 
  • Severe hepatic impairment (Child-Pugh class C):

    • No dosage adjustments 

Side Effects of Oritavancin (Orbactiv):

  • Cardiovascular:

    • Tachycardia
    • Hypersensitivity Angiitis
    • Peripheral Edema
  • Central Nervous System:

    • Headache
    • Dizziness
  • Dermatologic:

    • Erythema Multiforme
    • Pruritus
    • Skin Rash
    • Urticaria
  • Endocrine & Metabolic:

    • Hyperuricemia
    • Hypoglycemia
  • Gastrointestinal:

    • Nausea
    • Vomiting
    • Diarrhea
  • Hematologic & Oncologic:

    • Anemia
    • Eosinophilia
  • Hepatic:

    • Increased Serum ALT
    • Increased Serum AST
    • Increased Total Serum Bilirubin
  • Hypersensitivity:

    • Angioedema
    • Hypersensitivity Reaction
  • Infection:

    • Abscess
  • Local:

    • Injection Site Phlebitis
    • Injection Site Reaction
    • Erythema At Injection Site
    • Extravasation
    • Induration At Injection Site
  • Neuromuscular & Skeletal:

    • Myalgia
    • Osteomyelitis
    • Tenosynovitis
  • Respiratory:

    • Bronchospasm
    • Wheezing

Contraindications to Oritavancin (Orbactiv):

  • Intolerance to oritavancin or any other ingredient in this mixture
  • Use of IV UFH (unfractionated heparin) for five days following medication administration (it causes false elevation of aPTT for up to 5 days after administration)

Warnings and precautions

  • Hypersensitivity

    • There have been reports of severe hypersensitivity reactions (median onset in studies was 1.2 days).
    • If there is an acute reaction, it is important to stop the infusion immediately and provide supportive care (median resolution: 2.4 days).
    • Patients with a history glycopeptide allergy should be asked about any hypersensitivity reactions they have had in the past.
  • Infusion reactions

    • Reports of infusion-related reactions including urticaria, pruritus, and flushing have been made.
    • If there is a reaction, you can interrupt or slow down infusion.
  • Osteomyelitis

    • Patients treated with oritavancin had more osteomyelitis cases in clinical trials.
    • Patients should be kept an eye out for osteomyelitis symptoms and provided with alternative antimicrobial medication if necessary.
  • Superinfection

    • Oritavancin may result in bacterial or fungal superinfection. This includes pseudomembranous collitis and diarrhoea associated with C. difficile (CDAD) (CDAD).
    • More than two months after receiving treatment, several cases have been documented.

Oritavancin: Drug Interaction

Note: Drug Interaction Categories:

  • Risk Factor C: Monitor When Using Combination
  • Risk Factor D: Consider Treatment Modification
  • Risk Factor X: Avoid Concomitant Use

Risk Factor C (Monitor therapy)

Anticoagulants Oritavancin may lessen the anticoagulant's therapeutic effect. In particular, oritavancin may erroneously inflate the outcomes of laboratory tests frequently used to track anticoagulant efficacy, which could result in erroneous dosage reduction choices. There are certain exceptions, including Tinzaparin, Antithrombin, Bemiparin, Dalteparin, Enoxaparin, Fondaparinux, Nadroparin, and Protein C Concentrate (Human).
BCG Vaccine (Immunization) Antibiotics may reduce the BCG vaccine's therapeutic effect (Immunization).
Lactobacillus and Estriol The therapeutic effects of Lactobacillus and Estriol may be reduced by antibiotics.
Vitamin K Antagonists (eg, warfarin) The serum concentration of Vitamin K antagonists may rise when ritavancin is used.

Risk Factor D (Consider therapy modification)

Sodium Picosulfate Antibiotics may diminish the therapeutic effect of Sodium Picosulfate. Management: Consider using an alternative product for bowel cleansing prior to a colonoscopy in patients who have recently used or are concurrently using an antibiotic.
Typhoid Vaccine Antibiotics may diminish the therapeutic effect of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Management: Vaccination with live attenuated typhoid vaccine (Ty21a) should be avoided in patients being treated with systemic antibacterial agents. Use of this vaccine should be postponed until at least 3 days after cessation of antibacterial agents.

Risk Factor X (Avoid combination)

BCG (Intravesical) Antibiotics may diminish the therapeutic effect of BCG (Intravesical).
Cholera Vaccine Antibiotics may diminish the therapeutic effect of Cholera Vaccine. Management: Avoid cholera vaccine in patients receiving systemic antibiotics, and within 14 days following the use of oral or parenteral antibiotics.
Heparin Oritavancin may lessen heparin's therapeutic efficacy. In particular, oritavancin may unintentionally inflate the outcomes of laboratory tests frequently used to assess the efficacy of IV heparin, which could result in inaccurate decisions to reduce heparin doses.

Monitoring Parameters:

  • Baseline renal functions (serum urea nitrogen, creatinine) & liver function tests (AST, ALT, bilirubin).
  • Patients should be monitored for any kind of infusion-related reactions i.e pruritus, urticaria, flushing, signs & symptoms of osteomyelitis & hypersensitivity reactions (especially in patients with known glycopeptide allergy).

How to administer Oritavancin (Orbactiv)?

  • Intravenous: Infuse over three hours.
  • Use dextrose water to cleanse the IV line before and after each infusion if a standard IV line is being used to administer oritavancin along with other medications.
  • If an infusion-related reaction i.e pruritus, urticaria, flushing occurs, consider interrupting or slowing infusion.

Mechanism of action of Oritavancin (Orbactiv):

  • This lipoglycopeptide has bactericidal action that is concentration-dependent.
  • By interacting with the stempeptides of peptidoglycan precursors, it prevents the formation of cell walls.
  • By tying up bridging segments and compromising the integrity of the bacterial membrane, this prevents cross-linking.

Protein binding:

  • 85%

Metabolism:

  • metabolized

Half-life elimination:

  • About 245 hours

Excretion:

  • Excreted in feces and urine as unchanged drug (less than 1% in feces & 5% in urine, over 2 weeks  after administration)

International Brand Names of Oritavancin:

  • Orbactiv

Oritavancin Brand Names in Pakistan:

No Brands Available in Pakistan.