Drugs to Avoid in Heart Failure: Calcium Channel Blockers, NSAIDs and DPP-4 Inhibitors

BNP and NT-proBNP are released in response to myocardial wall stress, so a normal BNP with a normal ECG makes acute heart failure very unlikely as the cause of a patient's breathlessness — the dyspnoea is most likely pulmonary or another non-cardiac cause. One nuance: in a patient presenting late, days after the onset of acute heart failure while partially compensating, BNP can occasionally read lower than expected, so very recent-onset context still matters.

This is congestive cardiac failure — combined right and left heart failure — and the patient should ideally be hospitalised for close monitoring of renal function and electrolytes. For NYHA class 3 or 4 patients like this, we now routinely add acetazolamide alongside loop diuretics, which improves diuresis and speeds resolution of congestion as long as renal function isn't severely impaired. If blood pressure is low, low-dose renal-dose dopamine in addition to diuretics can help significantly, particularly with right heart failure and valvular dysfunction. Given the liver cirrhosis, use a higher dose of spironolactone, since it also acts on hepatic ascites, and monitor hepatorenal function closely.

The mechanism is glycosuria, which is a nidus for genitourinary infections — balanitis in men and UTIs in women, at an incidence of around 5 to 6%. Counsel every patient on personal and perineal hygiene when starting the drug. If a genitourinary infection develops, get a urine culture, and if confirmed, hold the SGLT2 inhibitor until it resolves, then restart with reinforced hygiene counselling.

There is no substantial long-term beneficial role — it is like flogging a dead horse, a transient cardiac output boost without sustained benefit. It's useful only as a short-term emergency bridge for a profoundly hypotensive patient. We now more routinely use noradrenaline rather than dobutamine in acute low-output heart failure.

The Sgarbossa criteria identify acute myocardial infarction in the presence of a left bundle branch block, where it is otherwise difficult to tell whether ECG changes represent an acute MI or simply the LBBB pattern — specifically, 4mm or more of ST elevation discordant to the QRS is considered an acute MI regardless of the LBBB. This is used specifically in the context of chest pain with LBBB, not in the context of established heart failure management.

Both types. Dihydropyridines such as amlodipine, felodipine and nifedipine, and non-dihydropyridines such as verapamil and diltiazem, are contraindicated because they worsen left ventricular function.

They don't improve outcomes and are associated with an increased risk of hospitalisation.

DPP-4 inhibitors such as saxagliptin and linagliptin. In diabetic patients, they should be replaced with an SGLT2 inhibitor first, then metformin.

No. It has no benefit when used routinely and is reserved specifically for documented non-sustained ventricular tachycardia with a clear indication.

Yes. NSAIDs cause sodium and fluid retention, which worsens both heart failure and renal function.