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Safe and appropriate use of ramipril


From 1 December 2022, ramipril (brand name: Tryzan) became fully funded without restriction and can be prescribed for any relevant use. These uses include hypertension, heart failure, progressive kidney disease, diabetic kidney disease, and prevention of cardiovascular events in those with established heart disease.


Mr Fapuleai is a 65-year-old Samoan man who has an appointment to renew the script for his regular medications. He has diagnoses of hypertension, hyperlipidaemia, and prediabetes.

Current medications:
Cilazapril 5mg orally once daily
Felodipine 5mg orally once daily
Atorvastatin 40mg orally once daily

He is stable on these medications with a blood pressure today of 130/74mmHg. Home readings sit below 130/80mmHg. Recent bloods show normal renal function. You calculate his creatinine clearance (CrCL) to be 55mL/min.

You explain to Mr Fapuleai that cilazapril is going off the market in mid 2023, and discuss the need to change to a different ACE inhibitor.

Ramipril mechanism of action

Ramipril is a prodrug and is hydrolysed into the active metabolite ramiprilat, which has a long half-life allowing once-daily dosing.

ACE inhibitors reduce the conversion of angiotensin I to angiotensin II and inhibit the breakdown of bradykinin. This reduces vascular smooth muscle vasoconstriction, increases renal excretion of sodium and water thus reducing blood volume and blood pressure, and is nephroprotective via reducing filtration pressure in the kidneys.2 


Safety and side effects

Ramipril shares common side effects, cautions, contraindications, and interactions with all other ACE inhibitors.1,3

Common side effects include:

Dry, persistent cough
This is the most common side effect of any ACE, experienced by around 11% of patients. This is more common in women, and often worse lying down and/or at night. Cough is generally a class effect of all ACE inhibitors. If cough is troublesome on one ACE inhibitor, changing to a different anti-hypertensive class may be required.

Alternatively, a change in anti-hypertensive class may be required.

This can occur with the first dose and with escalating doses, and particular caution is needed in those also on diuretic medications or who are volume deplete.

To avoid this initial drop in those on diuretics, the diuretic may be withheld for 2-3 days prior to starting then re-introduced. If this isn’t possible, consider a lower initial dose of 1.25mg.

Renal impairment 
It is likely that serum creatinine will slightly rise after starting an ACE inhibitor. If creatinine rises more than 30% from previous baseline, or eGFR drops by more than 25%, the dose should be reduced or stopped and other causes for decline investigated.

If serum potassium rises to greater than 5.9mmol/L the drug should be stopped.

For an extensive list of side effects see the New Zealand Formulary (NZF) monograph on ramipril, ‘adverse effects’ section.



  • Hypersensitivity to a previous ACE inhibitor
  • Previous angioedema - idiopathic or hereditary
  • Hypotension
  • Concurrent use with an angiotensin receptor blocker (ARB) or Entresto
  • Pregnancy
  • Severe bilateral renal artery stenosis 2


Pertinent interactions for a primary care setting

Interacting drug/class

Potential risks

ARB Renal impairment, hypotension, hyperkalaemia
Entresto Angioedema, renal impairment
Allopurinol In the context of pre-existing renal impairment: leucopaenia, hypersensitivity
Lithium Increased Lithium levels
Spironolactone Hyperkalaemia

The benefits and risks of different ACE inhibitors are very similar across the class.3




A practical approach for starting or changing to ramipril

Tryzan comes in capsule form with available strengths of 1.25mg, 2.5mg, 5mg, and 10mg. The capsules cannot be split or halved. It can be taken with or without food.1

Starting de novo

  • Identify a clear clinical indication.
  • Obtain the baseline blood pressure and renal function.
  • Check for interactions or contra-indications.
  • Prescribe ramipril at the recommended starting dose as per the NZF - the initial dose depends on the indication and CrCL.2
  • Arrange renal function 1-2 weeks after starting, followed by a clinic appointment to check blood pressure and toleranc.
  • Titrate dose as required.

Changing from another ACE inhibitor or ARB

  • Identify and discuss the rationale for changing (e.g. currently on cilazapril).
  • Discontinue current ACE inhibitor or ARB.
  • Identify the equivalent dose of ramipril.
  • Start ramipril to take at the same time the next dose would be due.
  • Arrange renal function 1-2 weeks after starting, followed by a clinic appointment to check blood pressure and tolerance.
  • Titrate dose as required.


Equivalent dosing for ACE/ARB medicines

bpacnz 2021

From Reference 3: Prescribing ACE inhibitors: time to reconsider old habits bpacnz (2022)

You describe Tryzan to Mr Fapuleai as a ‘cousin’ of cilazapril that he can safely change to at an equivalent dose. This will work in a similar way to maintain control of his blood pressure.

After discussing dosing and safety information, you relay the plan below:

  1. Stop cilazapril.
  2. Start ramipril at an equivalent dose of 10mg (1 tablet) once daily the following day.
  3. Get a blood test 1-2 weeks after starting ramipril to check kidney function.

You arrange for Mr Fapuleai to come back in two weeks after the blood tests to recheck blood pressure, and discuss any issues that arise with the transition.

This MedCase was written by Dr Hazel Wilks (MBChB), with expert review by Dr Hari Talreja, Consultant Renal Physician, MD, DNB, MPH (Harvard), FRACP.


  1. Tryzan
  2. Ramipril
  3. Tryzan

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