Drugs Used to Treat Heart Failure!

Introduction

Heart failure does not mean the heart has failed. Instead, the term refers to an inability of the heart to efficiently pump blood around the body. For this to happen, the heart may have become too weak or too rigid. Here, we review drugs used in heart failure, as well as which drugs to avoid / to be used with caution.

In 2015, heart failure affected over 40 million people. Risk of death within the first-year post-diagnosis is approximately 30 percent.

Causes of heart failure include coronary heart disease, high blood pressure, cardiomyopathy, heart rhythm disorders, damage to heart valves and congenital heart disease. Exposure to a previous heart attack also increases the risk of developing heart failure.

Symptoms of heart failure include:

• Tiredness
• Shortness of breath
• Dizziness
• Cough
• Peural effusion – excess fluid around the lungs
• Swelling in the abdomen – known as ascites
• Swelling in the ankles and legs

Shortness of breath is exacerbated while lying down or by engaging in exercise.

Drugs Used in Heart Failure

Treatment of heart failure depends on the patient – the cause of the disease and its severity. Patients with stable, mild heart failure are typically recommended lifestyle modifications (smoking cessation, changes to diet, exercise etc.).

Before we review drugs to avoid in heart failure, let’s quickly review the drugs that are used. Medications – often more than one – may be used

These include:

• Diuretics – to prevent fluid retention and its causing shortness of breath.
• ACE inhibitors dilating blood vessels to make it easier for the heart to pump blood. Examples include ramipril
• Angiotensin receptor blockers – also known as ‘sartans’. They have a similar effect to ACE inhibitors but are not associated with a persistent, dry cough.
• Beta blockers – drugs that slow the heart; protecting it from the effects of epinephrine and norepinephrine. Examples include bisoprolol and nebivolol.
• Sacubitril / Valsartan – combination of an angiotensin receptor blocker (valsartan) and sacubitril, which works as a neprilysin inhibitor. It is frequently reserved for patients with severe heart failure.
• Aldosterone antagonists– drugs that work as diuretics, lowering blood pressure and reducing fluid accumulation. Unlike other diuretics, they are not associated with hyperkalemia. Examples include spironolactone and eplerenone.
• Hydralazine – often used alongside a nitrate; the combination of which works to open up blood vessels and produce a pronounced hypotensive effect.

The combination of drugs chosen depends on severity. For example – patients are often only given aldosterone antagonists and hydralazine in severe heart failure. Many patients are given two or three medications.

For some patients, surgery is required. In these cases, a device may be implanted to control heart rhythm. In extreme cases, a heart transplant is required.

Drugs to Avoid in Heart Failure

Many drugs can exacerbate heart failure; both its symptoms and disease progression. Some drugs are absolutely contraindicated, whilst others are relatively contraindicated.

Below, we’ve put together many of these drugs – learning how each drug class impacts patients with heart failure – whether mild, moderate or severe heart failure.

• NSAIDs – drugs that promote fluid retention, increase blood pressure and which can cause kidney damage, such as acute kidney failure. These effects serve to increase heart workload and so directly worsen heart failure and the patient’s symptoms. Examples of NSAIDs include naproxen and ibuprofen. Low-dose aspirin, as recommended by the patient’s physician, is largely exempt from this rule.
• Triptans – triptans are medicines used to treat migraine. Examples include sumatriptan and zolmitriptan. By narrowing blood vessels around the body, they increase cardiovascular risks.
• Non-dihydropyridine calcium channel blockers – examples of which include verapamil and diltiazem. Both drugs have negative inotropic effects, meaning that they can depress cardiac function. The risk is higher with verapamil. Dihydropyridine CCBs – such as amlodipine and nifedipine – may be used to treat comorbidities – such as high blood pressure and coronary heart disease.
• Antiarrhythmic drugs – some antiarrhythmic drugs, such as flecainide, increases the risk of ventricular arrhythmias and may worsen heart failure. Similarly, dronedarone has been linked to an elevated mortality risk in some patients.
• Tricyclic antidepressants – drugs that increase the risk of QT prolongation in patients with heart failure.
• Thiazolidinediones – drugs also known as ‘glitazones’ – for example; pioglitazone and rosiglitazone. Both drugs can cause fluid retention by increasing sodium reabsorption from the kidney. Rosiglitazone also increases the risk of myocardial infarction.
• Corticosteroids – may worsen heart failure by increasing fluid retention and by increasing blood pressure. High dose corticosteroids also increase the risk of cardiac arrhythmias.
• Clozapine – increases the risk of cardiomyopathies and myocarditis.
• Monoclonal antibodies – some monoclonal antibodies, such as infliximab and etanercept, increase the risk of causing heart failure.
• OTC drugs – some drugs available without a prescription may also worsen heart failure / symptoms the patient experiences. For example – medicines that contain high sodium content increase the risk of fluid retention. Medicines that contain pseudoephedrine, often found in cough and cold preparations, may increase cardiac workload.

It’s worth re-emphasizing that some of these contraindications are relative, whilst others are absolute. The patient, their condition and drug recommendations must be considered on a case-by-case basis as determined by their physician.

Some of the above drugs may be recommended should clinical benefits outweigh any risks. Nonetheless, the above risks should be considered in patients with heart failure.