- In 2017, NHS England published a document advising prescribers to switch doxazosin XL to standard release doxazosin. This is because doxazosin XL has a significantly higher cost and relevant clinical guidelines do not identify any benefits of using it above standard release doxazosin.
- There are no recommendations from manufacturers or any published data available to suggest how to switch from doxazosin XL to standard release doxazosin. Therefore, in the absence of any firm recommendations, we suggest possible strategies to conduct this switch.
- Upon discontinuation of modified release doxazosin, the dose of standard doxazosin could be re-initiated at 1mg daily, as if newly starting therapy, or at half the modified release doxazosin dose. Converting to the same dose of standard release doxazosin may be another option.
- In each of these instances, all patients will require monitoring of blood pressure and some patients will need subsequent dose increases and titration until the desired efficacy is achieved.
- Patients should be made aware of the risks associated with postural hypotension and how to manage them, for example, avoiding situations where falls as a result of dizziness or faintness could result in injury.
Regional Medicines Information Manager, London Medicines Information Service