Table 3Initiation, titration and monitoring of ACE inhibitors in patients after acute MI

Doses
ACE inhibitors should be started at an appropriate dose and titrated upwards until the optimum or target dose* is reached.
Which ACE inhibitor and target dose*
The doses are taken from the BNF for a post MI secondary prevention indication, the notes below indicate the specific licensed indication.
Licensed ACE inhibitor
Starting doseTarget dose
Captopril**6.25 mg tds50 mg tds
Lisinopril2.5 mg – 5 mg od10 mg od
Ramipril***1.25 – 2.5 mg bd5 mg bd
Trandalopril**0.5 mg od4 mg od
Enalapril****2.5 mg od20 mg od or 10 mg bd
These are the licensed recommended doses for post MI patients, and may differ from those for patients with symptomatic heart failure. In patients with asymptomatic LV systolic dysfunction aim for the target dose recommended in those with symptomatic heart failure and LV systolic dysfunction (refer to the NICE guidelines for chronic heart failure).
** licensed for use in patients following MI with left ventricular dysfunction.
*** licensed for use following myocardial infarction in patients with clinical evidence of heart failure and also susceptible patients over 55 years, prevention of MI, stroke, cardiovascular death or need of revascularisation procedures.
**** licensed for use in patients for prevention of symptomatic heart failure in patients with left ventricular dysfunction (this may include patients with MI in the past).
How to use
  • Avoid in patients with known severe renal artery stenosis.
  • Check renal function (creatinine) and serum electrolytes (particularly potassium), and blood pressure at baseline.
  • Seek specialist advice in patients taking a high dose loop diuretic (for example furosemide 80mg od) or if concerned about the risk of renal artery stenosis (for example if severe peripheral vascular disease).
  • Initiate a low dose of ACE inhibitor.
  • Titrate the dose of ACE inhibitor upwards at short intervals (for example every 1 to 2 weeks).
  • Monitor renal function (creatinine) and serum electrolytes, and blood pressure before starting an ACE inhibitor, again within 1 to 2 weeks of starting treatment. Monitor thereafter until treated with a stable dose, and then at least annually. More frequent monitoring should be considered in patients at risk of deterioration in renal function and or of developing hyperkalaemia, or during an intercurrent illness.
  • Aim for target dose, or maximum tolerated dose.
What to do if blood pressure is low
  • If asymptomatic, low blood pressure does not usually require any change in therapy.
  • If low blood pressure is symptomatic (dizziness, lightheadedness and or confusion), stop non-essential hypotensive agents (for example alpha blockers, diuretics if for hypertension and or if no signs of congestion).
  • If these measures do not resolve the problem seek specialist advice.
What to do with deteriorating renal function and hyperkalaemia
  • If serum creatinine is unchanged, continue to titrate upwards the ACE inhibitor, with monitoring of renal function (creatinine) and serum electrolytes, and blood pressure.
  • If serum creatinine increases > 30% from baseline, stop other potentially nephrotoxic drugs (for example NSAIDs), non-essential vasodilators (for example alpha blockers), and potassium retaining drugs (for example amiloride, triamterene), and if no signs of cardiac failure reduce dose of any diuretics. Consider seeking specialist advice.
  • Repeat after 1 week and if serum creatinine persistently increased > 30% from baseline, half the dose of ACE inhibitors, and if serum creatinine persistently > 30% above baseline, seek specialist advice.
  • If serum creatinine increases ≥50% from baseline, stop other potentially nephrotoxic drugs (for example NSAIDs), stop non-essential vasodilators (for example nitrates, alpha blockers), and potassium retaining drugs (for example amiloride, triamterene) and if no signs of congestion, reduce dose of any diuretics. Consider stopping the ACE inhibitor and or seeking specialist advice.
  • Repeat after 1 week and if serum creatinine persistently increased > 50% from baseline, stop the ACE inhibitor if still treated and seek specialist advice
  • If serum creatinine increases > 100% from baseline, or serum creatinine is > 350 micromol/l stop the ACE inhibitor and seek specialist advice.
  • A rise in serum potassium to ≤ 5.5 mmol/l is acceptable. If serum potassium rises to 5.6–5.9 mmol/l, review concomitant medication, and advice against the use of ‘lo-salt’ substitutes which may be high in potassium, repeat serum potassium after 1-2 weeks.
  • If serum potassium ≥6 mmol/l, stop the ACE inhibitor and seek specialist advice.
  • The rate of rise as well as the absolute level of serum potassium should be taken into account.
Adapted from the recommendations for monitoring ACE inhibitors in the NICE guidelines for the diagnosis and management of chronic heart failure in primary and secondary care , and part 2 of the renal National Serμvice Framework.

From: 6, Drug Therapy

Cover of Post Myocardial Infarction
Post Myocardial Infarction: Secondary Prevention in Primary and Secondary Care for Patients Following a Myocardial Infarction [Internet].
NICE Clinical Guidelines, No. 48.
National Collaborating Centre for Primary Care (UK).
Copyright © 2007, National Collaborating Centre for Primary Care.

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