Arthrocentesis and Joint Injection in Patients Receiving Direct Oral Anticoagulants – Yui et al – Mayo Clinic 2017

  • DOAC (direct-acting anticoagulants) or NOAC (Novel Oral Anticoagulants) –  rivaroxaban [Xarelto], apixaban [Eliquis], and dabigatran [Pradaxa]
  • Joint aspiration / injection seems safe in patients on DOAC.
  • In 1050 consecutive procedures, there were no bleeding complications.
  • Conclusion – Arthrocentesis and joint injections in patients receiving DOAC therapy are safe procedures, and there is no need to withhold anticoagulation treatment before the procedure.

The Risks of Continuing or Discontinuing Anticoagulants for Patients Undergoing Common Interventional Pain Procedures – Endres et al, Pain Medicine 2017

  • Aim of the study was to determine if continuing or discontinuing anticoagulants for pain procedures was associated with a detectable risk of complications.
  • This was an observational study where some clinicians continued to do interventions without stopping anticoagulants whilst some discontinued anticoagulants.
  • There were no complications attributable to anticoagulants encountered in 4,766 procedures in which anticoagulants were continued.
  • In 2,296 procedures in which anticoagulants were discontinued, nine patients suffered serious morbidity, including two deaths.
Conclusion: Lumbar transforaminal injections, lumbar medial branch blocks, trigger point injections, and sacroiliac joint blocks appear to be safe in patients who continue anticoagulants. In patients who discontinue anticoagulants, although low (0.2%) the risk of serious complications is not zero, and must be considered when deciding between continuing and discontinuing anticoagulants

Update of a Study of Not Ceasing Anticoagulants for Patients Undergoing Injection Procedures for Spinal Pain – Endres et al, Pain Medicine 2020

  • A total of 1,936 consecutive patients were prospectively monitored during a total of 12,723 injection procedures.
  • The prevalence of hemorrhagic complications was tallied for a variety of procedures performed on patients who ceased or continued various anticoagulants.
  • No hemorrhagic complications occurred in any patient who continued anticoagulants.
Conclusion: Lumbar transforaminal injections and lumbar facet injections have a very low rate of hemorrhagic complications when patients continue to take anticoagulants

Determination of a safe INR for joint injections in patients taking warfarin – Bashir et al – Annals Royal College of Surgeons of England 2015

  • 41 patients on warfarin were given 86 injections either landmark guided by ortho surgeons or US guided by radiologists. None had any haemarthrosis post injection.
Conclusion – With a mean INR of 2.77 (range, 1.7-5.5) and a maximum INR within this group of 5.5, joint injections to the shoulder and knee can be undertaken safely in primary or secondary care settings despite the patient taking warfarin

Safety of joint and soft tissue injections in patients on warfarin anticoagulation – Conway et al – Rheumatology 2013

  • 2 Groups with 32 procedures each. For one group warfarin was stopped, other group continued to take warfarin.
  • In group who continued on warfarin, 27 were joint injections and 5 were soft tissue injections.
  • There were no clinical hemarthroses or complications in either group.
Conclusion – Joint and soft tissue injections appear to be safe in patients receiving warfarin anticoagulation with an INR <3

Hand Corticosteroid Injections in Patients on “Blood Thinners” – Malige & Matullo – Hand NY 2020

  • There were 6 complications after 433 injections (1.6%) placed in patients on blood thinners and 6 complications after 1040 injections (0.6%) placed in patients not on blood thinners.
  • Conclusion – With the complication rate of corticosteroid injections being so low, even in patients taking “blood thinners,” the fear of adverse reactions should not preclude a physician from using this treatment modality to prevent surgical intervention

Dental extractions on direct oral anticoagulants vs. warfarin: The DENTST study – Research and practice in thrombosis and haemostasis – Brennan et al 2020

Conclusion – Dental extractions on patients continuing DOACs led to bleeding rates similar to patients on warfarin with an INR between 2.0 and 4.0. There is no need to adjust DOAC dosing prior to dental extractions.

Should we fear direct oral anticoagulants more than vitamin K antagonists in simple single tooth extraction? A prospective comparative study – Clinical oral investigations – Berton et al 2019

Clinical relevance: Patients assuming DOACs can be treated similarly to patients in VKAs therapy with INR index between 2 and 3. Non-ceasing of DOAC therapy seems to be appropriate for simple single dental extractions.

What is Half Life | Drugs

Half life is the time it takes in the body for the concentration of the drug to reduce by half.

For example, if a 100 mg of a drug has a half life of 1 hour or 60 minutes then the following estimates can be made.

  • After 1 hour or 60 minutes of administration of the drug, 50mg will remain in the body.
  • After 2 hours, 25mg will remain.
  • After 3 hours, 12.5mg will remain.
  • so on and so forth.

It is considered that most drugs have negligible effect after 4-5 half life cycles.

It is not that straightforward however. Drug metabolism depends upon various body organs such as liver and kidneys. Someone with kidney dysfunction for example may have longer drug half lives as it will take longer for the drug to leave the system as the function of kidneys is impaired. Likewise for drugs metabolised in liver, it may take longer in someone with liver disease.

Half life of Apixaban – Eliquis

  • Half life of Apixaban is around 12 hours

Half life of Rivaroxaban – Xarelto

  • Elimination of rivaroxaban from plasma occurs with a terminal half-life of 5–9 h in healthy young subjects and 11–13 h in elderly subjects

Half life of Dabigatran – Pradaxa

  • In patients with normal renal function, approximately 80% of an intravenous dabigatran dose is excreted in urine with an elimination half-life of 12–17 h