Zofenopril Other names: Zofenoprilum

The administration of non-steroidal anti-inflammatory agents may reduce the antihypertensive effect of an ACE inhibitor. Furthermore, it has been described that NSAIDS and ACE inhibitors exert an additive effect on the increase in serum potassium whereas renal function may decrease. These effects are in principle reversible, and occur especially in patients with compromised renal function. Rarely, acute renal failure may occur, particularly in patients with compromised renal function such as older people or dehydrated.

May reduce the antihypertensive effects of ACE inhibitors; patients should be carefully monitored to confirm that the desired effect is being obtained.

Patients with moderate to severe renal impairment (creatinine clearance <45ml/min) should be given one-half the therapeutic dose of zofenopril; the once-daily dosage regimen does not require modification.

In hypertensive patients with mild to moderate hepatic impairment, the starting dose of zofenopril is half of the dose for patients with normal hepatic function.

Reduce the bioavailability of ACE inhibitors.

Rarely ACE inhibitors can potentiate the blood glucose-reducing effects of insulin and oral antidiabetics like sulphonylurea, in diabetics. In such cases it may be necessary to reduce the dose of the antidiabetic during simultaneous treatment with ACE inhibitors.

There may be additive hypotensive effect or potentiation. Treatment with nitroglycerine and other nitrates, or other vasodilators, should be used with caution. Clinical trial data has shown that dual blockade of the renin-angiotensin-aldosterone-system (RAAS) through the combined use of ACE-inhibitors, angiotensin II receptor blockers or aliskiren is associated with a higher frequency of adverse events such as hypotension, hyperkalaemia and decreased renal function (including acute renal failure) compared to the use of a single RAAS-acting agent.

Prior treatment with high dose diuretics may result in volume depletion and a risk of hypotension when initiating therapy with zofenopril. The hypotensive effects can be reduced by discontinuation of the diuretic, by increasing volume or salt intake or by initiating therapy with a low dose of zofenopril.

ACE inhibitors attenuate diuretic induced potassium loss. Potassium sparing diuretics e.g. spironolactone, triamterene, or amiloride, potassium supplements, or potassium-containing salt substitutes may lead to significant increases in serum potassium. If concomitant use is indicated because of documented hypokalemia they should be used with caution and with frequent monitoring of serum potassium and ECG.

Concomitant administration with ACE inhibitors may lead to an increased risk of leucopenia.

Nitritoid reactions (symptoms of vasodilatation including flushing, nausea, dizziness and hypotension, which can be very severe) following injectable gold (for example, sodium aurothiomalate) have been reported more frequently in patients receiving ACE inhibitor therapy.

ACE inhibitors may enhance the hypotensive effects of certain anaesthetic medicinal products.

Postural hypotension may occur.

Increased risk of renal dysfunction when ACE inhibitors are used concurrently.

May enhance the risk of hypotensive effect.

Reversible increases in serum lithium concentrations and toxicity have been reported during concomitant administration of lithium with ACE inhibitors. Concomitant use of thiazide diuretics may increase the risk of lithium toxicity and enhance the already increased risk of lithium toxicity with ACE inhibitors. Therefore, zofenopril is not recommended in association with lithium and careful monitoring of serum lithium levels should be performed if the concomitant use proves necessary.

There is an increased risk of severe hypotension and renal insufficiency when patients with renovascular hypertension and pre-existing bilateral renal artery stenosis or stenosis of the artery to a solitary kidney are treated with ACE inhibitors. Treatment with diuretics may be a contributory factor. Loss of renal function may occur with only mild changes in serum creatinine even in patients with unilateral renal artery stenosis. If considered absolutely necessary, treatment with zofenopril should be started in hospital under close medical supervision with low doses and careful dose titration. Diuretic treatment should be discontinued temporarily when therapy with zofenopril is initiated and renal function be closely monitored during the first few weeks of therapy.

Patients with primary aldosteronism generally will not respond to antihypertensive drugs acting through inhibition of the renin-angiotensin system. Therefore the use of this product is not recommended.

As with other ACE inhibitors, zofenopril may cause a profound fall in blood pressure, especially after the first dose, although symptomatic hypotension is seen rarely in uncomplicated hypertensive patients.

It is more likely to occur in patients who have been volume and electrolyte depleted by diuretic therapy, dietary salt restriction, dialysis, diarrhoea or vomiting, or who have severe renindependent hypertension.

In patients with heart failure, with or without associated renal insufficiency, symptomatic hypotension has been observed. This is more likely to occur in those patients with more severe degrees of heart failure, as reflected by the use of high doses of loop diuretics, hyponatraemia or functional renal impairment. In patients at increased risk of symptomatic hypotension, treatment should be started under close medical supervision preferably in the hospital, with low doses and careful dose titration.

If possible, diuretic treatment should be discontinued temporarily when therapy with zofenopril is initiated. Such considerations apply also to patients with angina pectoris or cerebrovascular disease in whom an excessive fall in blood pressure could result in a myocardial infarction or cerebrovascular accident.

If hypotension develops, the patient should be placed in a supine position. Volume repletion with intravenous normal saline may be required. he appearance of hypotension after the initial dose does not preclude subsequent careful dose titration with drug after effective management.

In some patients with heart failure who have normal or low blood pressure, additional lowering of systemic blood pressure may occur with zofenopril. This effect is anticipated and is not usually a reason to discontinue treatment. If hypotension becomes symptomatic, a reduction of dose or discontinuation of zofenopril may be necessary.

Hypotension in acute myocardial infarction

Treatment with zofenopril must not be initiated in acute myocardial infarction patients if there is a risk of additional serious heamodynamic depression following treatment with a vasodilator. These are patients with a systolic blood pressure of <100mmHg or with cardiogenic shock. Treatment with zofenopril in acute myocardial infarction patients may lead to severe hypotension. In the case of persistent hypotension (systolic blood pressure <90mmHg for more than one hour), zofenopril should be discontinued. In patients with severe heart failure following an acute myocardial infarction zofenopril should only be administered if the patient is haemodynamically stable.

Hyperkalaemia may occur during treatment with an ACE inhibitor. Patients at risk for the development of hyperkalaemia include those with renal insufficiency, diabetes mellitus or those using concomitant potassium-sparing diuretics, potassium supplements or potassium-containing salt substitutes; or in patients taking other active substances associated with increases in serum potassium (e.g. heparin). If concomitant use of the above mentioned agents is deemed appropriate, they should be used with frequent monitoring of serum potassium.

The starting dose and the dosage regimen of zofenopril for hypertensive patients maintained on dialysis should be one-quarter the dose used for patients with normal renal function.

Recent clinical observations have shown a high incidence of anaphylactoid-like reactions in patients on ACE inhibitors during haemodialysis with high-flux dialysis membranes or during LDL apheresis.

Patients who are dialysed using high-flux polyacrylonitrile membranes (e.g. AN 69) and treated with ACE inhibitors are likely to experience anaphylactoid reactions such as facial swelling, flushing, hypotension and dyspnoea within a few minutes of commencing haemodialysis. It is recommended to use an alternative membrane or an alternative antihypertensive medicinal product.

The efficacy and safety of zofenopril in myocardial infarction patients undergoing haemodialysis has not been established. Therefore, it should not be used in these patients.

Proteinuria may occur particularly in patients with existing renal function impairment or on relatively high doses of ACE inhibitors. Patients with prior renal disease should have urinary protein estimation (dip-stick on first morning urine) prior to treatment, and periodically thereafter.

Rarely, patients receiving ACE inhibitors during desensitisation treatment (e.g. hymenoptera venom) or after insect bites have experienced life-threatening anaphylactoid reactions. In the same patients, these reactions have been avoided when ACE inhibitors were temporarily withheld but they have reappeared upon inadvertent re-administration of the medicinal product. Therefore, caution should be used in patients treated with ACE inhibitors undergoing such desensitisation procedures.

ACE inhibitors may cause hypotension or even hypotensive shock in patients undergoing major surgery or during anaesthesia since they may block angiotensin II formation secondary to compensatory renin release. If it is not possible to withhold the ACE inhibitor, intravascular and plasma volumes should be carefully monitored.

Neutropenia/agranulocytosis, thrombocytopenia and anaemia have been reported in patients receiving ACE inhibitors. The risk of neutropenia appears to be dose- and type-related and is dependent on patient’s clinical status. It is rarely seen in uncomplicated patients but may occur in patients with some degree of renal impairment especially when it is associated with collagen vascular disease e.g. systemic lupus erythematosus, scleroderma and therapy with immunosuppressive agents, treatment with allopurinol or procainamide, or a combination of these complicating factors. Some of these patients developed serious infections which in a few instances did not respond to intensive antibiotic therapy.

If zofenopril is used in such patients, it is advised that white blood cell count and differential counts should be performed prior to therapy, every 2 weeks during the first 3 months of zofenopril therapy, and periodically thereafter. During treatment all patients should be instructed to report any sign of infection (e.g. sore throat, fever) when a differential white blood cell count should be performed. Zofenopril and other concomitant medication should be withdrawn if neutropenia (neutrophils less than 1000/mm³) is detected or suspected.

It is reversible after discontinuation of the ACE inhibitor.

During treatment with zofenopril a dry and non-productive cough may occur which disappears after discontinuation of zofenopril.

ACE inhibitor-induced cough should be considered as part of the differential diagnosis of cough.

ACE inhibitors should be used with caution in patients with mitral valve stenosis and obstruction in the outflow of the left ventricule.

Angioedema of the face, extremities, lips, mucous membranes, tongue, glottis and/or larynx may occur in patients treated with ACE inhibitors which occurs most frequently during the first weeks of treatment. However in rare cases severe angioedema may develop after long-term treatment with an angiotensin converting enzyme inhibitor. Treatment with ACE inhibitors should promptly be discontinued and replaced by an agent belonging to another class of drugs.

Angioedema involving the tongue, glottis or larynx may be fatal. Emergency therapy should be given including, but not necessarily limited to, immediate subcutaneous adrenaline solution 1:1000 (0.3 to 0.5ml) or slow intravenous adrenaline 1mg/ml (which should be diluted as instructed) with close monitoring of ECG and blood pressure. The patient should be hospitalised and observed for at least 12 to 24 hours and should not be discharged until complete resolution of symptoms has occurred.

Even in such instances where swelling of only the tongue is involved, without respiratory distress, patients may require observation since treatment with antihistamines and corticosteroids may not be sufficient.

Angiotensin converting enzyme inhibitors cause a higher rate of angioedema in black patients than in non-black patients.

Patients with a history of angioedema unrelated to ACE inhibitor therapy may be at increased risk of angioedema while receiving an ACE inhibitor.

ACE inhibitors should be used with caution in patients with psoriasis.

The use of ACE inhibitors is not recommended during the first trimester of pregnancy. The use of ACE inhibitors is contra-indicated during the second and third trimester of pregnancy.

Epidemiological evidence regarding the risk of teratogenicity following exposure to ACE inhibitors during the first trimester of pregnancy has not been conclusive; however a small increase in risk cannot be excluded. Unless continued ACE inhibitor is considered essential, patients planning pregnancy should be changes to alternative anti-hypertensive treatment which have an established safety profile for use in pregnancy. When pregnancy is diagnosed, treatment with ACE inhibitors should be stopped immediately, and, if appropriate, alternative therapy should be started.

ACE inhibitor therapy exposure during the second and third trimesters is known to induce human fetotoxicity (decreased renal function, oligohydramnios, skull ossification retardation) and neonatal toxicity (renal failure, hypotension, hyperkalaemia). Should exposure to ACE inhibitor have occurred from the second trimester of pregnancy, ultrasound check of renal function and skull is recommended. Infants whose mothers have taken ACE inhibitors should be closely observed for hypotension.

Because no information is available regarding the use of zofenopril during breastfeeding, zofenopril is not recommended and alternative treatments with better established safety profiles during breast-feeding are preferable, especially while nursing a newborn or preterm infant.

There are no studies on the effect of zofenopril on the ability to drive. When driving vehicles or operating machines it should be remembered that occasionally drowsiness, dizziness or weariness may occur.