The NHS Specialist Pharmacy Service have published a guide to Management of patients taking warfarin during the COVID-19 pandemic.
[See also: Guidance for Safe Switching of Warfarin to DOACs]
The guide recommends a stepwise approach:
- For patients with prior DVT or PE with low risk of recurrence, consider stopping warfarin.
- For other patients, consider switching to a DOAC – using a phased approach over a 12 week cycle to protect the supply chain, with priority for those with poor INR control.
- Seek specialist advice before switching people if any of the following apply:
- active malignancy and/or chemotherapy
- venous thrombosis at unusual sites
- taking phenytoin, carbamazepine, phenobarbitone or rifapicin
- dual antiplatelet plus warfarin triple therapy
- Where warfarin remains necessary (e.g.: prosthetic mechanical valve; consult cardiologist; moderate to severe mitral stenosis; antiphospholipid antibody syndrome; pregnant, breastfeeding or planning pregnancy; requires a higher INR; severe renal impairment; major drug interactions (e.g. HIV meds), consider options to minimise INR monitoring:
- extend INR intervals
- consider self-monitoring
- community monitoring via phlebotomy services
- self- or family/friend-supported-injection of LMWH