Captopril tablets discontinued – transition advice to another ACE inhibitor

Medicines

Decision

Due to a discontinuation in the supply of captopril tablets, 12.5 mg, 25 mg, and 50 mg (m-Captopril) tablets will no longer be funded.  We recommend that prescribers transition their patients to another funded alternative at the next practicable opportunity.

Captopril oral liquid 5 mg per ml will remain fully subsidised for children under 12 years of age.

Approximately 1300 patients are currently taking captopril, with 1000 having been on the treatment long term, out of a total of 290,000 patients who are currently on ACE inhibitor therapy.

There are a number of other fully funded ACE inhibitors available. The table below indicates suggested equivalent daily doses for other fully funded ACE inhibitors.

This table does not attempt to represent exact or equivalent dosing conversions but is based on approved dosing ranges and comparative doses from clinical trials used in the treatment of raised blood pressure. Practitioners should exercise clinical discretion in the practical application of this guide, including consideration of a patient’s current cardiovascular risk and other clinical variables[1]. As with titration of any ACE inhibitor, when switching patients it is important to monitor renal function and blood pressure. Blood pressure should be checked a week after a change has occurred, as by then a steady state should be reached.

In general, there is little difference between each of the ACE inhibitors when used for the treatment of raised blood pressure. Enalapril is most commonly used for congestive heart failure, however dosing equivalents are not as easy to determine due to factors like renal function and use of diuretics.

CURRENT CAPTOPRIL DOSES suggested cilazapril daily dosing suggested enalapril daily dosing suggested lisonopril daily dosing suggested quinapril daily dosing
25 mg daily 1 mg 2.5 mg1 5 mg 5 mg
50 mg daily 2 mg 5 - 7.5 mg1 10 mg 10 mg
100 mg daily 4 mg 20 mg* 20 mg 20 mg
150 mg daily 5 mg 40 mg 40 mg 40 mg
  • This table does not represent exact or equivalent dosing conversions. It is based on FDA-approved dosing ranges and comparative doses from clinical trials used in the treatment of raised blood pressure.
  • For lower doses of captopril (12.5 mg daily) a proportion of the other recommended doses should be used.

*Doses have been rounded to nearest convenient dose form. A dose equivalency between enalapril:captopril of 1:7.5 is suggested for the treatment of raised blood pressure.

Equivalent dosing, as indicated in the above table, is difficult as captopril should not be used as a once daily medication. Average daily doses for each of the ACE inhibitors are captopril 37.5 mg = lisinopril 10mg = enalapril 5mg = quinapril 10mg = cilazapril 2mg. Usual doses for the above are cilazapril 2.5mg daily; enalapril 20-40mg daily (40mg as 20mg bid); lisinopril 10-40mg daily, and quinapril 20-40mg daily (some sources suggest 80mg daily). Twice daily dosing is preferable for quinapril if the dose is 40mg daily.