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Lipoglycopeptide antibiotic Pregnancy: §4.6, verbatim: 'There are no or limited amount of data (less than 300 pregnancy outcomes) from the use of oritavancin in pregnant women. Animal studies do not indicate direct or indirect harmful effects with respect to reproductive toxicity. As a precautionary measure, it is preferable to avoid the use of Tenkasi during pregnancy unless the clinical condition of the woman requires treatment with oritavancin.' Breast-feeding, verbatim: 'It is unknown whether oritavancin/metabolites are excreted in human milk. A risk to the newborns/infants cannot be excluded. A decision must be made whether to discontinue breast-feeding or to discontinue/abstain from Tenkasi therapy.'

Oritavancin

Brand names: Orbactiv, Tenkasi

Oritavancin is a long-acting lipoglycopeptide antibacterial used as a single intravenous infusion for acute bacterial skin and soft-tissue infections caused by Gram-positive organisms.

Adult dose

Dose: 1200 mg as a single dose. §4.2, verbatim: 'Adults 1 200 mg administered as a single dose by intravenous infusion over 3 hours.'
Route: Intravenous infusion over 3 hours. §4.2, verbatim: 'Each of the three 400 mg vials should first be reconstituted with 40 mL of sterile water for injection (WFI). The reconstituted solutions should be withdrawn and added to a 1 000 mL glucose 5% intravenous bag (D5W) for an intravenous infusion over 3 hours ... Only D5W should be used for dilution. Sodium chloride solution should not be used for dilution.'
Frequency: Single dose — one 1200 mg infusion is the whole course; no repeat dose is described in §4.2.
maxDose is blank deliberately: the adult regimen is a fixed single 1200 mg dose and §4.2 states no adult ceiling. The only 'maximum' cue in §4.2 belongs to the paediatric 15 mg/kg calculation and is recorded in the paediatric block, not here. The 3-hour infusion is itself a safety measure — §4.4, verbatim: 'Oritavancin is given via intravenous infusion over 3 hours, to minimise the risk of infusion-related reactions.' Cover for co-pathogens must be added separately — §4.4, verbatim: 'Oritavancin is active against Gram-positive bacteria only ... In mixed infections where Gram-negative and/or certain types of anaerobic bacteria are suspected, oritavancin should be co-administered with appropriate antibacterial agent(s).' Elderly: 'No dose adjustment is required for patients ≥ 65 years of age.'

Paediatric dose

Dose: 15 mg/kg
Route: Intravenous infusion over 3 hours — diluted in glucose 5% (D5W) only; sodium chloride solution must not be used
Frequency: Single dose
Max: Maximum 1200 mg as a single dose
Concentration: 1.2 mg/ml
§4.2, verbatim: 'Paediatric patients aged 3 months to < 18 years 15 mg/kg administered as a single dose by intravenous infusion over 3 hours (maximum 1 200 mg).' This is a single per-dose per-kilogram figure that applies across the whole licensed paediatric range, so it drives the weight calculator directly, capped at the SPC's own 1200 mg ceiling. concentration is 1.2 mg/ml because that is the final infusion concentration the SPC itself specifies for this calculation — §4.2 Table 1 heading, verbatim: 'Table 1: 15 mg/kg Body Weight Dose of Oritavancin: 3-Hour Infusion (Concentration of 1.2 mg/ml)' — and it reproduces the SPC's own volumes exactly (5 kg → 75 mg → 62.5 ml; 20 kg → 300 mg → 250 ml; 40 kg → 600 mg → 500 ml). Lower age limit — §4.2, verbatim: 'The safety and efficacy of oritavancin in paediatric patients < 3 months of age have not yet been established.' Paediatric safety experience is small: §4.8, verbatim: 'The safety assessment in paediatric patients is based on data from one trial in which 38 patients aged from 3 months to 18 years with suspected or confirmed Gram-positive bacterial infection received Tenkasi.' Verify against a children's formulary and paediatric infectious-diseases advice.

Dose adjustments

Renal

§4.2, verbatim: 'No dose adjustment is needed in patients with mild or moderate renal impairment. Very limited data are available in patients with severe renal impairment. Renal impairment had no clinically relevant effect on the exposure of oritavancin, however caution should be exercised when prescribing oritavancin in patients with severe renal impairment. Oritavancin is not removed from blood by haemodialysis procedures.'

Hepatic

§4.2, verbatim: 'No dose adjustment is required for patients with mild to moderate hepatic impairment (Child-Pugh Class B) ... The pharmacokinetics of oritavancin in patients with severe hepatic impairment (Child-Pugh Class C) has not been evaluated, however based on pharmacokinetic parameters, severe hepatic impairment is not expected to have an impact on oritavancin exposure. Therefore no dose adjustment is required, even if caution should be exercised when prescribing oritavancin to patients with severe hepatic impairment (Child-Pugh Class C).'

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Paediatric weight-based calculator

§4.2, verbatim: 'Paediatric patients aged 3 months to < 18 years 15 mg/kg administered as a single dose by intravenous infusion over 3 hours (maximum 1 200 mg).' This is a single per-dose per-kilogram figure that applies across the whole licensed paediatric range, so it drives the weight calculator directly, capped at the SPC's own 1200 mg ceiling. concentration is 1.2 mg/ml because that is the final infusion concentration the SPC itself specifies for this calculation — §4.2 Table 1 heading, verbatim: 'Table 1: 15 mg/kg Body Weight Dose of Oritavancin: 3-Hour Infusion (Concentration of 1.2 mg/ml)' — and it reproduces the SPC's own volumes exactly (5 kg → 75 mg → 62.5 ml; 20 kg → 300 mg → 250 ml; 40 kg → 600 mg → 500 ml). Lower age limit — §4.2, verbatim: 'The safety and efficacy of oritavancin in paediatric patients < 3 months of age have not yet been established.' Paediatric safety experience is small: §4.8, verbatim: 'The safety assessment in paediatric patients is based on data from one trial in which 38 patients aged from 3 months to 18 years with suspected or confirmed Gram-positive bacterial infection received Tenkasi.' Verify against a children's formulary and paediatric infectious-diseases advice.

Verify in a children's formulary

Contraindications

  • Hypersensitivity to the active substance or to any of the excipients (§4.3)
  • Intravenous unfractionated heparin sodium for 120 hours (5 days) after oritavancin — §4.3, verbatim: 'because the activated partial thromboplastin time (aPTT) test results may remain falsely elevated for up to 120 hours after oritavancin administration'

Side effects

  • Nausea, vomiting, diarrhoea, constipation — common (§4.8)
  • Hypersensitivity reactions; anaphylactic reaction uncommon, anaphylactic shock frequency not known (§4.8)
  • Infusion site reactions — common: phlebitis, erythema, extravasation, induration, pruritus, rash, peripheral oedema (§4.8)
  • Headache and dizziness — common (§4.8)
  • Cellulitis and limb or subcutaneous abscess — common; osteomyelitis — uncommon (§4.8)
  • Anaemia — common; eosinophilia and thrombocytopenia — uncommon (§4.8)
  • Abnormal liver function tests (raised ALT and AST) — common; raised blood bilirubin — uncommon (§4.8)
  • Urticaria, rash, pruritus — common; angioedema, erythema multiforme, leucocytoclastic vasculitis, flushing — uncommon (§4.8)
  • Tachycardia and myalgia — common (§4.8)
  • Infusion-associated reactions: chest pain, chest discomfort, chills, tremor, back pain, neck pain, dyspnoea, hypoxia, abdominal pain and fever (§4.4, §4.8)
  • Hypoglycaemia and hyperuricaemia — uncommon (§4.8)

Monitoring

  • Coagulation assays are unreliable after a dose — §4.4, verbatim: oritavancin artificially prolongs 'aPTT for up to 120 hours, PT and INR for up to 12 hours, Activated Clotting Time (ACT) for up to 24 hours, Silica Clot Time (SCT) for up to 18 hours, and Dilute Russell's Viper Venom Test (DRVVT) for up to 72 hours'; if aPTT monitoring is needed within 120 hours use a non-phospholipid-dependent test such as a chromogenic factor Xa assay
  • Anticoagulant effect of warfarin — §4.4, verbatim: 'making the monitoring of the anticoagulation effect of warfarin unreliable up to 12 hours after an oritavancin dose'
  • Watch during and after the infusion for hypersensitivity and infusion-related reactions; stop the infusion immediately for an acute hypersensitivity reaction, and slowing or stopping may abort an infusion reaction (§4.4)
  • Patients with any history of glycopeptide hypersensitivity — careful monitoring during and after the infusion because cross-reactivity data are absent (§4.4)
  • Clinical response, and cover for Gram-negative or anaerobic co-pathogens where a mixed infection is suspected (§4.4)

Clinical monograph

How it works

It inhibits bacterial cell-wall synthesis by binding to peptidoglycan precursors and also disrupts the bacterial membrane, giving bactericidal activity against Gram-positive bacteria including MRSA.

Prescribing in practice

  • It artefactually prolongs coagulation tests such as aPTT and PT/INR for a period after administration and is contraindicated with intravenous unfractionated heparin during that interval, so heparin monitoring becomes unreliable.
  • Its very long half-life means adverse effects can persist for an extended period after the single dose.
  • It is for Gram-positive skin and soft-tissue infection only and has no useful activity against Gram-negative organisms.

Monitoring

Be aware that coagulation tests are unreliable for a period after dosing; otherwise monitor for infusion reactions and clinical response.

Counselling the patient

  • This treatment is usually given as a single infusion by trained staff.
  • Tell any clinician you have received it, as it can affect blood-clotting test results for some days.

Evidence & guidelines

Single-dose efficacy in skin and soft-tissue infection is supported by the SOLO randomised trials and described in the SPC.

Reference: SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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