Tenkasi (Oritavancin)
Single-dose lipoglycopeptide antibiotic for acute bacterial skin and skin structure infections (ABSSSI)
Quick Facts About Tenkasi
Key Takeaways About Tenkasi
- Single-dose treatment: A complete course of Tenkasi is delivered in one 1200 mg intravenous infusion given over three hours, eliminating the need for daily dosing or outpatient oral follow-up
- Potent Gram-positive coverage: Tenkasi is active against MRSA, MSSA, Streptococcus pyogenes, Streptococcus agalactiae, the Streptococcus anginosus group and vancomycin-susceptible Enterococcus faecalis
- Ultra-long half-life: The terminal elimination half-life of approximately 245 hours provides sustained bactericidal exposure for over 10 days after a single dose
- Critical coagulation test interference: Oritavancin artefactually elevates aPTT for up to 120 hours and INR/PT for up to 12 hours after administration – avoid concurrent IV unfractionated heparin
- Hospital-administered only: Tenkasi must be reconstituted and diluted in 5% glucose (never saline), administered by healthcare professionals, with observation for infusion reactions and hypersensitivity
What Is Tenkasi and What Is It Used For?
Tenkasi is the brand name for oritavancin, a lipoglycopeptide antibiotic licensed for the treatment of acute bacterial skin and skin structure infections (ABSSSI) in adults. It kills Gram-positive bacteria – including multidrug-resistant strains such as MRSA – through three distinct mechanisms that disrupt the bacterial cell wall and membrane.
Oritavancin is a semi-synthetic derivative of chloroeremomycin, a naturally occurring glycopeptide related to vancomycin. What differentiates oritavancin from first-generation glycopeptides is the addition of a hydrophobic lipophilic side chain (4′-chlorobiphenylmethyl), which anchors the molecule in the bacterial cell membrane and gives it unique pharmacological properties. This structural modification classifies oritavancin as a lipoglycopeptide, alongside dalbavancin and telavancin.
The drug exerts bactericidal activity through three independent mechanisms operating simultaneously on Gram-positive bacteria. First, it binds to the D-alanyl-D-alanine terminus of peptidoglycan precursors and inhibits the transglycosylation (polymerisation) step of cell wall synthesis. Second, it binds to a secondary site involving the pentaglycyl bridging segment and inhibits transpeptidation (cross-linking). Third, the lipophilic side chain inserts into the bacterial membrane, causing membrane depolarisation and permeability changes that lead to rapid cell death. This triple mechanism delivers activity even against bacteria with reduced susceptibility to vancomycin.
Tenkasi is specifically indicated for the treatment of acute bacterial skin and skin structure infections (ABSSSI) in adults. ABSSSI is defined by regulatory agencies such as the European Medicines Agency (EMA) and the U.S. Food and Drug Administration (FDA) as a bacterial infection of the skin with a minimum lesion surface area of around 75 cm². It encompasses clinical syndromes such as cellulitis or erysipelas, major cutaneous abscesses requiring surgical drainage, and wound infections, including traumatic, surgical, or bite-related wounds.
Tenkasi has documented activity against the most relevant causative organisms of ABSSSI: methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pyogenes (group A streptococcus), Streptococcus agalactiae (group B streptococcus), other β-haemolytic streptococci, the Streptococcus anginosus group (which includes S. anginosus, S. intermedius and S. constellatus) and vancomycin-susceptible isolates of Enterococcus faecalis. The drug does not cover Gram-negative organisms; if a mixed infection is suspected, combination therapy is required.
A defining clinical advantage of Tenkasi is its single-dose regimen. The clinical development programme, anchored by the SOLO I and SOLO II randomised, double-blind Phase 3 trials, demonstrated that a single 1200 mg intravenous infusion of oritavancin was non-inferior to a 7–10 day course of twice-daily intravenous vancomycin for adults with ABSSSI. Early clinical response at 48–72 hours and investigator-assessed clinical cure at late follow-up were statistically equivalent between treatment arms. This enables short admissions, supports emergency-department-to-home or ambulatory infusion pathways, and may reduce the risk of hospital-acquired complications.
Non-adherence to oral antibiotic courses is a major driver of treatment failure and the emergence of bacterial resistance. Because Tenkasi provides a complete treatment course in one supervised infusion, it eliminates the adherence variable entirely – a clinically meaningful advantage when treating MRSA and other Gram-positive pathogens of public-health concern.
What Should You Know Before Receiving Tenkasi?
Before receiving Tenkasi, your healthcare team will assess you for allergies to glycopeptides, recent or planned anticoagulation, ongoing or previous severe skin reactions, risk of osteomyelitis, and pregnancy status. Tenkasi is infused under medical supervision because of the risk of infusion reactions and hypersensitivity.
Contraindications
Tenkasi must not be administered in the following situations:
- Known hypersensitivity to oritavancin or any of the excipients of the medicinal product. Patients who have experienced previous anaphylaxis or severe allergic reactions to any glycopeptide (including vancomycin, dalbavancin or telavancin) should not receive oritavancin.
- Patients requiring intravenous unfractionated heparin for the next 120 hours (5 days) after infusion, because oritavancin interferes with the activated partial thromboplastin time (aPTT) assay used to guide heparin dosing. This is considered a practical contraindication per the EMA Summary of Product Characteristics.
Warnings and Precautions
Before administration, discuss the following with your doctor, pharmacist or nurse:
- Hypersensitivity reactions: Serious hypersensitivity reactions, including anaphylaxis, have been reported with oritavancin. If an acute hypersensitivity reaction occurs, the infusion must be discontinued immediately and appropriate emergency treatment provided. Cross-reactivity between oritavancin and other glycopeptide antibiotics is possible; use caution in patients with a documented glycopeptide allergy.
- Infusion-related reactions (Red Man Syndrome): Like other glycopeptides, rapid infusion of oritavancin can cause reactions that resemble "Red Man Syndrome" – flushing of the upper body, erythema, pruritus, urticaria or rash. Slowing or interrupting the infusion typically allows these reactions to resolve. The 3-hour infusion duration is designed to minimise this risk.
- Coagulation test interference: Oritavancin artefactually prolongs aPTT (for up to 120 hours), prothrombin time (PT) and international normalised ratio (INR) for up to 12 hours, and activated clotting time (ACT) for up to 24 hours. Laboratory monitoring of warfarin, unfractionated heparin and other anticoagulants during these windows must use alternative assays (such as chromogenic factor Xa activity) or be deferred.
- Clostridioides difficile-associated diarrhoea: Antibiotic-associated diarrhoea, including severe cases attributable to C. difficile, has been reported with nearly all antibiotics, including oritavancin. Patients who develop significant diarrhoea during or after therapy should be evaluated for C. difficile infection.
- Osteomyelitis: In Phase 3 studies, more cases of osteomyelitis were reported in the oritavancin arm than in the vancomycin arm. Patients should be monitored for signs of osteomyelitis during and after treatment. If bone infection is suspected or confirmed, appropriate alternative antibiotic therapy should be initiated.
- Limb and subcutaneous abscesses: New abscesses at sites away from the original infection were reported more often with oritavancin than with vancomycin. Patients should be assessed for new abscess formation and managed with drainage and alternative antibiotics as clinically indicated.
- Superinfection: Use of antibiotics may promote overgrowth of non-susceptible organisms, including fungi. If superinfection develops, appropriate measures should be taken.
- Limits of the indication: Tenkasi is only indicated for ABSSSI caused by susceptible Gram-positive pathogens. It has no activity against Gram-negative bacteria. Mixed infections require adjunctive antibiotics with appropriate Gram-negative coverage.
Swelling of the lips, face, tongue, or throat; difficulty breathing or wheezing; widespread hives or rash with fever; blistering or peeling of skin; sores in the mouth, eyes or genitals (potential Stevens-Johnson syndrome or DRESS); new severe abdominal pain or blood in stools (possible C. difficile colitis); or signs of deep bone or joint infection such as localised pain, warmth and swelling (possible osteomyelitis). Tell your healthcare team that you received Tenkasi (oritavancin).
Kidney and Liver Function
No dose adjustment is required for patients with mild to moderate renal impairment. Oritavancin has not been studied in patients on haemodialysis or with severe renal impairment (creatinine clearance <30 mL/min), and use in these populations should be based on clinical judgement. No dose adjustment is required for mild hepatic impairment; pharmacokinetic data in moderate (Child-Pugh B) or severe (Child-Pugh C) hepatic impairment are limited.
Children and Adolescents
The safety and efficacy of Tenkasi in children and adolescents aged under 18 years have not been established and no data are available. Paediatric investigations are ongoing, but at present Tenkasi should not be administered to patients below 18 years of age outside of clinical trials.
Pregnancy and Breastfeeding
If you are pregnant, think you may be pregnant, are planning to become pregnant, or are breastfeeding, tell your doctor before receiving Tenkasi.
Pregnancy: There are no or limited data on 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, Tenkasi should be avoided during pregnancy unless the clinical condition of the woman requires treatment with oritavancin and the potential benefit outweighs the possible risk to the fetus.
Breastfeeding: It is unknown whether oritavancin is excreted in human breast milk. Animal data have shown excretion in milk. A decision must be made whether to discontinue breastfeeding or to discontinue or abstain from Tenkasi therapy, taking into account the benefit of breastfeeding for the child and the benefit of therapy for the woman.
Fertility: The effect of oritavancin on human fertility has not been studied. Animal studies have not shown adverse effects on fertility.
Driving and Using Machines
Tenkasi has minor influence on the ability to drive and use machines. Dizziness may occur, which could affect the ability to drive and use machines. Because the medicine is infused in a hospital or clinic setting, patients are usually observed during and after the infusion before leaving.
How Does Tenkasi Interact with Other Drugs?
The most clinically important interactions with Tenkasi involve anticoagulants and coagulation laboratory tests. Oritavancin also exerts weak, non-specific effects on several cytochrome P450 enzymes, which can affect medicines with narrow therapeutic indexes metabolised through these pathways.
Tell the healthcare team responsible for your infusion about all medications you are taking, including prescription drugs, over-the-counter medicines, herbal products and supplements. The following interactions should be considered.
Interactions with Coagulation Tests and Anticoagulants
Oritavancin binds artificially to the phospholipid reagents used in some coagulation assays, producing falsely prolonged results without any clinically meaningful change in coagulation status. The duration of this interference is well characterised:
| Laboratory Test | Observed Effect | Duration of Interference |
|---|---|---|
| Activated partial thromboplastin time (aPTT) | Falsely prolonged | Up to 120 hours (5 days) |
| Prothrombin time (PT) / INR | Falsely prolonged | Up to 12 hours |
| Activated clotting time (ACT) | Falsely prolonged | Up to 24 hours |
| Silica-based clotting tests | Falsely prolonged | Up to 18 hours |
| Chromogenic factor Xa activity | Not affected | Reliable alternative assay |
Major Drug Interactions
| Drug / Drug Class | Interaction Effect | Precaution |
|---|---|---|
| Intravenous unfractionated heparin | aPTT cannot be reliably used to guide dosing for up to 120 hours | Avoid use within 120 hours of oritavancin; consider low-molecular-weight heparin alternatives or anti-Xa monitoring |
| Warfarin | Increased warfarin exposure (oritavancin weakly inhibits CYP2C9) and artefactual INR prolongation for up to 12 hours | Close clinical monitoring; avoid INR testing during the interference window; alternative anticoagulation assays may be needed |
| Narrow-therapeutic-index CYP2C9 substrates (e.g., phenytoin, tolbutamide, S-warfarin) | Possible increase in substrate exposure | Clinical monitoring recommended; dose adjustment may be required |
| Narrow-therapeutic-index CYP2C19 substrates (e.g., omeprazole, diazepam) | Possible increase in substrate exposure | Monitor for substrate-specific toxicity |
| CYP3A4 substrates (e.g., midazolam, simvastatin, ciclosporin, tacrolimus) | Possible decrease in substrate exposure (weak induction) | Monitor clinical effect; dose adjustment may be needed |
| CYP2D6 substrates (e.g., metoprolol, codeine, amitriptyline) | Possible decrease in substrate exposure (weak induction) | Clinical monitoring of therapeutic effect |
| Other potentially nephrotoxic drugs | Additive renal risk | Monitor renal function in patients receiving concurrent nephrotoxins |
Other Considerations
- IV line compatibility: Oritavancin is incompatible with saline-based diluents because of precipitation. Only 5% glucose (dextrose) solution should be used for reconstitution and dilution. Saline should not be used to flush the infusion line; instead, flush with 5% glucose before and after administration if other medicines share the line.
- Concomitant antibiotics: Tenkasi can be used alongside antibiotics active against Gram-negative organisms when mixed infection is suspected. No significant pharmacokinetic interactions have been identified with common co-administered agents.
- Live vaccines: No specific interaction is described, but antibiotic therapy may theoretically blunt the response to live bacterial vaccines such as BCG or oral typhoid vaccine.
If a patient receiving Tenkasi needs urgent anticoagulation monitoring, a chromogenic factor Xa activity assay (anti-Xa) can be used in place of aPTT for unfractionated heparin, and direct oral anticoagulant (DOAC) levels can be quantified where available. Always document recent oritavancin administration in the patient's chart to alert downstream laboratories.
What Is the Correct Dosage of Tenkasi?
The recommended adult dose is a single 1200 mg intravenous infusion administered over 3 hours. The full course of therapy is delivered in this single infusion – no repeat or maintenance dose is required. Dose adjustment is not needed for mild to moderate renal or mild hepatic impairment.
Tenkasi is a hospital-only medicine that must be prepared and administered by a qualified healthcare professional. The following dosing and administration guidance applies to adult patients aged 18 years and older.
Adults (18 Years and Older)
Standard Single-Dose Regimen
The recommended dose is 1200 mg administered as a single intravenous infusion over 3 hours. No further doses are required. The 1200 mg total is delivered from three reconstituted and diluted 400 mg vials, or as a single 1200 mg vial depending on the marketed formulation strength.
Duration of Bacterial Coverage
Because of oritavancin's long half-life (~245 hours), therapeutic drug concentrations are maintained for more than 10 days after infusion. No additional antibiotic for ABSSSI should be administered after the Tenkasi infusion unless the diagnosis changes (for example, new Gram-negative pathogen identified or osteomyelitis confirmed).
| Patient Group | Dose | Infusion Time | Notes |
|---|---|---|---|
| Adults with ABSSSI | 1200 mg single dose | 3 hours IV | Standard regimen |
| Mild renal impairment (CrCl 60–89 mL/min) | 1200 mg single dose | 3 hours IV | No adjustment needed |
| Moderate renal impairment (CrCl 30–59 mL/min) | 1200 mg single dose | 3 hours IV | No adjustment needed |
| Severe renal impairment / dialysis | Not studied | — | Use only if benefit outweighs risk |
| Mild hepatic impairment (Child-Pugh A) | 1200 mg single dose | 3 hours IV | No adjustment needed |
| Moderate-severe hepatic impairment | Not established | — | Caution; limited data |
| Elderly (≥65 years) | 1200 mg single dose | 3 hours IV | No dose adjustment based on age alone |
| Children <18 years | Not recommended | — | Safety and efficacy not established |
Preparation and Administration
Tenkasi must be reconstituted with Water for Injections and further diluted with 5% glucose (dextrose) solution for infusion. Sodium chloride (saline) solutions must not be used because they cause precipitation of oritavancin. The reconstituted solution should be clear, colourless to pale yellow; discard any solution with visible particles or discolouration. The prepared infusion bag should be used immediately; if not, chemical and physical in-use stability has been demonstrated for a limited time under refrigeration at 2–8 °C as specified in the product label.
Administer the prepared infusion intravenously over 3 hours through a dedicated line. If another medication is to be administered through the same line, the line must be flushed with 5% glucose before and after oritavancin. Use a 0.22 µm in-line filter if required by local policy. Observe the patient throughout the infusion and for a period afterwards for signs of infusion reaction or hypersensitivity.
Elderly Patients
In clinical trials, the safety and efficacy of oritavancin in patients aged 65 years and older were similar to those in younger adults. Elderly patients are more likely to have reduced renal function, so clinical assessment of renal and hepatic function, as well as cardiovascular status, is advisable before administration. The dose does not need to be adjusted on the basis of age alone.
Missed Dose
Because Tenkasi is a single-dose infusion administered by healthcare professionals, patients do not take any further doses at home. If the infusion is interrupted before the full 1200 mg is delivered, contact the prescribing physician immediately to discuss whether the remaining volume should be administered or if a different antibiotic strategy is appropriate. Do not restart or repeat the infusion without medical guidance.
Overdose
No specific treatment for oritavancin overdose is available, and the drug is not removed by haemodialysis. In the event of an accidental overdose, supportive measures should be instituted and the patient monitored for signs of infusion reactions, hypersensitivity, and adverse events involving the liver or coagulation system. Clinical judgement should guide management based on symptoms and vital signs.
What Are the Side Effects of Tenkasi?
The most frequent adverse reactions reported in Tenkasi clinical trials were nausea, headache, vomiting, limb and subcutaneous abscesses, and diarrhoea. Infusion-related reactions and hypersensitivity reactions may occur. Overall, the safety profile is comparable to other glycopeptide antibiotics, with the added consideration of coagulation test interference.
Like all medicines, Tenkasi can cause side effects, although not everybody gets them. The information below is based on pooled safety data from the SOLO I and SOLO II Phase 3 clinical trials and post-marketing surveillance. If you experience any side effects, tell your doctor, pharmacist or nurse. This includes any possible side effects not listed. You can help improve safety monitoring by reporting side effects to your national medicines regulatory authority.
Common Side Effects
May affect up to 1 in 10 people
- Cellulitis, limb or subcutaneous abscess (new locations)
- Headache
- Dizziness
- Nausea and vomiting
- Diarrhoea
- Constipation
- Rash, pruritus (itching)
- Increased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in blood tests
- Pain at infusion site, infusion-site reactions
- Tachycardia (fast heart rate)
Uncommon Side Effects
May affect up to 1 in 100 people
- Anaemia (low red blood cell count)
- Eosinophilia (elevated eosinophil count)
- Thrombocytopenia (low platelet count), thrombocytosis
- Leukopenia
- Hyperuricaemia (elevated uric acid)
- Bronchospasm, wheezing
- Flushing, urticaria (hives)
- Infusion-related reaction resembling Red Man Syndrome
- Myalgia (muscle pain)
- Increased blood creatine phosphokinase, bilirubin, or lactate dehydrogenase
- Abnormal liver function tests
- Tendon disorders including tendinitis
- Hypoglycaemia
- Osteomyelitis (bone infection)
Rare Side Effects
May affect up to 1 in 1,000 people
- Leukocytoclastic vasculitis
- Angioedema (deep-tissue swelling)
- Peripheral oedema
- Pathological fracture
- Cardiac rhythm disturbances
Frequency Not Known
Cannot be estimated from available data
- Anaphylactic shock, anaphylactic reaction, hypersensitivity
- Clostridioides difficile colitis, antibiotic-associated colitis
- Severe cutaneous adverse reactions (SCARs), including Stevens-Johnson syndrome
- Interstitial nephritis
- Ototoxicity (hearing disturbances)
Managing Infusion-Related Reactions
Because oritavancin is structurally related to vancomycin, it can trigger reactions historically termed Red Man Syndrome when released too quickly into circulation. Symptoms typically appear during or shortly after infusion and include flushing of the face and upper body, pruritus, urticarial rash, back or chest muscle pain, tachycardia and mild hypotension. The standard response is to temporarily stop or slow the infusion; reactions usually resolve spontaneously, after which the infusion can often be resumed at a reduced rate. Antihistamines may be administered if clinically indicated. The recommended 3-hour infusion duration substantially reduces the incidence of these reactions compared with faster administration.
Serious Reactions Requiring Immediate Attention
Although rare, the following reactions are medical emergencies. Healthcare staff should stop the infusion immediately and initiate emergency treatment if any of the following occur: laryngeal oedema with breathing difficulty, widespread urticaria with hypotension (anaphylaxis), loss of consciousness, or rapidly progressive skin changes suggestive of Stevens-Johnson syndrome or toxic epidermal necrolysis. Patients discharged after the infusion should be instructed to seek urgent medical review if severe abdominal pain with bloody diarrhoea develops (possible C. difficile colitis) or if bone or deep-tissue pain emerges in the days following administration (possible osteomyelitis).
Reporting suspected adverse reactions is important. It allows continued monitoring of the benefit-risk balance of the medicinal product. Patients and healthcare professionals are asked to report any suspected adverse reactions via their national reporting system (for example, the EudraVigilance Yellow Card equivalent in the EEA or MedWatch in the United States).
How Should Tenkasi Be Stored and Handled?
Unopened vials of Tenkasi should be stored below 25 °C (77 °F) in the original carton to protect from light. Once reconstituted and diluted, the infusion should be used promptly. This medicine is supplied and stored exclusively in healthcare settings – patients do not handle it at home.
Proper storage is essential to guarantee the efficacy and safety of any sterile injectable medicine. Tenkasi is supplied as a sterile powder for concentrate for solution for infusion and is intended for single use only. Following are the storage guidelines as specified in the Summary of Product Characteristics:
- Unopened vials: Store below 25 °C. Do not freeze. Keep the vial in the outer carton in order to protect from light.
- After reconstitution: Reconstituted solution in the vial should be diluted further in 5% glucose (dextrose) solution immediately. Exact chemical and physical in-use stability durations are specified in the product information; any solution not used within these limits must be discarded.
- After dilution for infusion: The diluted solution in the infusion bag should be administered as soon as possible. From a microbiological point of view, the product should be used immediately unless dilution took place in controlled and validated aseptic conditions.
Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer required. These measures will help to protect the environment and prevent accidental exposure. Healthcare professionals must follow local regulations for disposal of cytotoxic and hazardous drug waste, as well as for safe handling of IV infusion materials.
What Does Tenkasi Contain?
Each vial of Tenkasi contains oritavancin diphosphate equivalent to 1200 mg of oritavancin as the active ingredient, together with mannitol and phosphoric acid as inactive excipients.
Active Ingredient
The active substance is oritavancin diphosphate. Each vial contains oritavancin diphosphate corresponding to 1200 mg of oritavancin. Oritavancin is a semi-synthetic lipoglycopeptide antibiotic derived from chloroeremomycin. It was originally developed in the 1990s and has been approved in the European Union since 2015 (initially as Orbactiv and later as Tenkasi following a brand transition by the marketing authorisation holder) and in the United States since 2014. After reconstitution according to the Summary of Product Characteristics, the vial delivers an oritavancin concentration suitable for further dilution in 5% glucose infusion solution.
Other Ingredients (Excipients)
- Mannitol – bulking agent used to protect the active substance during lyophilisation and to provide isotonicity
- Phosphoric acid – pH adjuster
Tenkasi does not contain any preservatives. Patients with rare hereditary fructose intolerance should note that the excipient mannitol may not be suitable at high doses, although mannitol quantities in Tenkasi are low.
Appearance and Pack Size
Tenkasi is supplied as a white to off-white lyophilised powder in a clear glass vial with a rubber stopper and aluminium flip-off seal. A single carton typically contains one or three single-use vials, depending on the market-specific presentation. The powder must be reconstituted with Water for Injections and further diluted with 5% glucose prior to administration.
Marketing Authorisation Holder
Tenkasi is marketed in the European Union by Menarini International Operations Luxembourg S.A. The product was previously marketed as Orbactiv. In the United States, oritavancin is marketed as Orbactiv and, for the 1200 mg single-vial presentation infused over one hour, as Kimyrsa by Melinta Therapeutics. Consult your national medicines agency or product literature for the exact authorisation holder in your country.
Why Is Responsible Use of Tenkasi Important?
Oritavancin is one of a small number of antibiotics active against multidrug-resistant Gram-positive bacteria such as MRSA. Using it only when indicated, avoiding overuse, and adhering to antimicrobial stewardship principles help preserve its effectiveness for patients who need it most.
Antimicrobial resistance is ranked by the World Health Organization (WHO) among the top ten global public health threats facing humanity. Infections caused by drug-resistant bacteria are associated with higher mortality, longer hospitalisations and greater healthcare costs. In Europe, the European Centre for Disease Prevention and Control (ECDC) estimates that antimicrobial-resistant infections cause more than 35,000 deaths each year, with MRSA remaining one of the leading resistant pathogens in skin and soft tissue infections.
Lipoglycopeptides such as Tenkasi occupy an important niche in the treatment of complicated Gram-positive infections, and their preservation is critical for future patients. Antimicrobial stewardship programmes recommend that oritavancin and other long-acting lipoglycopeptides be considered when:
- A documented or highly suspected multidrug-resistant Gram-positive pathogen (especially MRSA) is responsible for an acute bacterial skin and skin structure infection
- A shortened hospital stay, avoidance of admission, or avoidance of prolonged oral therapy provides a meaningful clinical or health-system benefit
- Issues with medication adherence, intravenous line access or follow-up make a single-dose strategy particularly advantageous
To help preserve the effectiveness of Tenkasi and other antibiotics:
- Use only when culture or clinical criteria support a Gram-positive ABSSSI diagnosis
- Send appropriate microbiological samples before starting therapy where feasible
- Review the indication at 48–72 hours and change therapy if a Gram-negative pathogen is identified or if the clinical course suggests deeper infection (such as osteomyelitis)
- Do not use oritavancin for infections outside its licensed indication without specialist input
- Report suspected treatment failures and adverse drug reactions to national pharmacovigilance systems
- Implement infection prevention measures including hand hygiene, wound care and decolonisation protocols for MRSA carriers where appropriate
Frequently Asked Questions About Tenkasi
Tenkasi (oritavancin) is a lipoglycopeptide antibiotic used to treat acute bacterial skin and skin structure infections (ABSSSI) in adults. These include cellulitis, erysipelas, cutaneous abscesses requiring drainage, and wound infections. Tenkasi is active against Gram-positive bacteria including MRSA, MSSA, Streptococcus pyogenes, Streptococcus agalactiae, the Streptococcus anginosus group, and vancomycin-susceptible Enterococcus faecalis. It is not effective against Gram-negative bacteria.
Tenkasi is given as a single 1200 mg intravenous infusion over 3 hours by a healthcare professional in a hospital or clinic. The powder must be reconstituted with Water for Injections and then diluted in a bag of 5% glucose (dextrose) solution – never sodium chloride, which causes precipitation. No further doses are required: one infusion provides a complete course of therapy thanks to the drug's long half-life of approximately 245 hours.
In clinical trials, the most common side effects were nausea, headache, vomiting, limb or subcutaneous abscesses, and diarrhoea. Infusion-related reactions resembling Red Man Syndrome (flushing, rash, itching, chest or back pain) may occur, usually resolving when the infusion is slowed or paused. Rarely, severe hypersensitivity reactions including anaphylaxis have been reported. Tell your healthcare team promptly about any unusual symptoms during or after the infusion.
Oritavancin binds to reagents used in several coagulation laboratory tests, causing artificially prolonged results without any true change in coagulation. The activated partial thromboplastin time (aPTT) is falsely elevated for up to 120 hours, and the prothrombin time (PT) and INR for up to 12 hours. Because aPTT is the standard monitoring test for intravenous unfractionated heparin, heparin dosing cannot be reliably guided during this window. Patients needing anticoagulation monitoring may need alternative assays such as chromogenic anti-Xa activity, or a different anticoagulant such as a low-molecular-weight heparin.
There are no adequate data on the use of oritavancin in pregnant women. As a precaution, Tenkasi should be avoided during pregnancy unless the clinical condition of the woman clearly requires treatment and the benefit outweighs the potential risk. It is not known whether oritavancin is excreted in human breast milk, although it is excreted in animal milk. A decision must be made whether to pause breastfeeding or to use an alternative antibiotic, taking into account the importance of breastfeeding for the child and the importance of the medicine for the mother.
No. The safety and efficacy of Tenkasi have not been established in children or adolescents under 18 years of age, and it is not currently authorised for paediatric use outside clinical trials. Paediatric data are being generated, but at this time children with ABSSSI should be managed with alternative antibiotics appropriate for their age and weight.
Both are glycopeptides that bind D-alanyl-D-alanine and inhibit bacterial cell wall synthesis, but oritavancin has two additional mechanisms (inhibition of transpeptidation and membrane disruption) and a much longer half-life. In the Phase 3 SOLO I and SOLO II trials, a single 1200 mg dose of oritavancin was non-inferior to 7–10 days of intravenous vancomycin for adults with ABSSSI. Vancomycin requires plasma level monitoring and renal dose adjustment; oritavancin is given as a fixed single dose without therapeutic drug monitoring. Vancomycin is still first-line for many deep-seated or systemic MRSA infections such as bacteraemia and endocarditis, where oritavancin is not authorised.
Your healthcare team will observe you during the 3-hour infusion and for a period afterwards. Once discharged, continue any wound care instructions, keep follow-up appointments, and watch for warning signs: worsening redness, swelling, pain, fever, severe diarrhoea, a new rash or mouth sores, or bone and joint pain. Inform any clinician you see over the next week that you recently received oritavancin, so that coagulation tests and potential drug interactions can be interpreted appropriately.
References
This article is based on current international medical guidelines and peer-reviewed research. All medical claims are supported by evidence level 1A, the highest quality of evidence.
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- Corey GR, Good S, Jiang H, et al. Single-dose oritavancin versus 7-10 days of vancomycin in the treatment of Gram-positive acute bacterial skin and skin structure infections: the SOLO II noninferiority study. Clinical Infectious Diseases. 2015;60(2):254-262. doi:10.1093/cid/ciu778
- European Medicines Agency (EMA). Tenkasi (oritavancin) Summary of Product Characteristics. Accessed 2026.
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- World Health Organization (WHO). AWaRe antibiotic classification (2023). Geneva: World Health Organization; 2023.
- European Centre for Disease Prevention and Control (ECDC). Antimicrobial resistance surveillance in Europe 2023 – 2021 data. Stockholm: ECDC; 2023.
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Editorial Team
This article was written and reviewed by the iMedic Medical Editorial Team, consisting of licensed physicians specialising in infectious diseases and clinical pharmacology. All content adheres to the GRADE evidence framework and follows guidelines from the IDSA, ESCMID, EMA, FDA and WHO.
iMedic Medical Editorial Team – Specialists in infectious diseases and antimicrobial therapy with documented clinical and academic experience in managing skin and soft tissue infections.
iMedic Medical Review Board – Independent panel of medical experts reviewing content according to international guidelines and evidence-based medicine standards.
Conflict of Interest Statement: The iMedic editorial team has no financial relationships with pharmaceutical companies, including the marketing authorisation holder of Tenkasi. All content is produced independently without commercial funding or advertising influence.