Patients on diuretics, and especially those started recently, may occasionally experience an excessive reduction of blood pressure after initiation of ACEON therapy. The possibility of hypotensive effects can be minimized by either decreasing the dose of or discontinuing the diuretic or increasing the salt intake prior to initiation of treatment with perindopril. If diuretic therapy cannot be altered, provide close medical supervision with the first dose of ACEON, for at least two hours and until blood pressure has stabilized for another hour [see Warnings and Precautions].
The rate and extent of perindopril absorption and elimination are not affected by concomitant diuretics. The bioavailability of perindoprilat was reduced by diuretics, however, and this was associated with a decrease in plasma ACE inhibition.
Potassium Supplements and Potassium-Sparing Diuretics
ACEON may increase serum potassium because of its potential to decrease aldosterone production. Use of potassium-sparing diuretics (spironolactone, amiloride, triamterene and others), potassium supplements or other drugs capable of increasing serum potassium (indomethacin, heparin, cyclosporine and others) can increase the risk of hyperkalemia. Therefore, if concomitant use of such agents is indicated, monitor the patient's serum potassium frequently.
Increased serum lithium and symptoms of lithium toxicity have been reported in patients receiving concomitant lithium and ACE inhibitor therapy. Frequent monitoring of serum lithium concentration is recommended. Use of a diuretic may further increase the risk of lithium toxicity.
Nitritoid reactions (symptoms include facial flushing, nausea, vomiting and hypotension) have been reported rarely in patients on therapy with injectable gold (sodium aurothiomalate) and concomitant ACE Inhibitor therapy including ACEON.
A controlled pharmacokinetic study has shown no effect on plasma digoxin concentrations when coadministered with ACEON, but an effect of digoxin on the plasma concentration of perindopril/perindoprilat has not been excluded.
Animal data have suggested the possibility of interaction between perindopril and gentamicin. However, this has not been investigated in human studies.
Non-Steroidal Anti-Inflammatory Agents including Selective Cyclooxygenase-2 Inhibitors (COX-2 Inhibitors)
In patients who are elderly, volume-depleted (including those on diuretic therapy), or with compromised renal function, co-administration of NSAIDs, including selective COX-2 inhibitors, with ACE inhibitors, including perindopril, may result in deterioration of renal function, including possible acute renal failure. These effects are usually reversible. Monitor renal function periodically in patients receiving perindopril and NSAID therapy.
The antihypertensive effect of ACE inhibitors, including perindopril, may be attenuated by NSAIDs including selective COX-2 inhibitors.
Dual Blockade of the Renin-Angiotensin System (RAS)
Dual blockade of the RAS with angiotensin receptor blockers, ACE inhibitors, or aliskiren is associated with increased risks of hypotension, hyperkalemia, and changes in renal function (including acute renal failure) compared to monotherapy. Closely monitor blood pressure, renal function and electrolytes in patients on ACEON and other agents that affect the RAS.
Do not co-administer aliskiren with ACEON in patients with diabetes. Avoid use of aliskiren with ACEON in patients with renal impairment (GFR <60 ml/min).