What You Need To Know About Inotropics
Christmas season is way past over, however, Nurse Hannah finds herself staring at a Christmas Tree-like ceiling. Like Colorful Christmas balls, IV hooks are full of different IV bottles of different sizes, all lines connected to the patient.
“Oh boy, this is going to be one exciting duty,” she says to herself as she proceeds to reading the chart.
Dopamine. Dobutamine. Norepinephrine. We do not always encounter those drugs in the area, however, once they are ordered, they give nurses the chill.
Inotropics: An overview
Basically, inotropics or inotropes are drugs that make a person’s heart beat more strongly as they affect the contraction of the heart muscle. In other words, an inotropic drug is a medicine that amends the force or strength of the heart’s muscular contractions or what is commonly known as the heart beat.
There are two different types of inotropic drugs: negative and positive. While the negative inotropics act to make the heart beat less strongly, positive inotropic drugs, on the other hand, make the heart beat more strongly. However different their effects may be, both kinds are used to manage various conditions that may affect the function of the heart, the kind of inotrope to be given depending on a patient’s condition.
Positive Inotropic Agents
This kind of inotrope that strengthens the force of the heart beat includes digoxin, dopamine, dobutamine, eicosanoids, epinephrine, inamrinone, isoprenaline, milrinone, norepinephrine, phosphodiesterase inhibitors, theophylline.
Here, the heart pumps more blood with fewer heartbeats meaning although the heart beats less, it also beats with more force to meet the oxygen demands of your body. Usually, this kind is given to patients with congestive heart failure, cardiomyopathy, heart attack and those experiencing cardiogenic shock (weakened heart) after surgery.
Dopamine used as medication acts on the sympathetic nervous system. Using dopamine results to increased heart rate and blood pressure. It is also a continuous IV infusion and increases the amount of norepinephrine active in your body. Usually, dopamine is used to help get rid of edema because of how it affects receptors in the kidney’s blood vessels. However, the nurse must also watch out for potential side effects such as irregular heart rhythm, and increased demand for oxygen by the heart
Like Dopamine, it is also used as a continuous IV infusion as it improves heart function and may lower blood pressure. It also helps your body make more use of a substance called norepinephrine, which stimulates your heart to work harder. It also makes a patient tolerant to the drug and larger doses might be required in time, it may also come to a point wherein the drug may no longer affect a patient anymore.
The nurse must watch out for potential side effects like irregular heart rhythm and increased demand for oxygen by the heart
Negative Inotropic Agents
This kind of inotrope weakens the contraction of the heart and slows the heart rate, it includes beta-blockers, calcium channel blockers, disopyramide, flecainide, procainamide, quinidine. Usually, these are ordered for patients to treat high blood pressure (hypertension), chronic congestive heart failure, abnormal heart rhythms (arrhythmias), and chest pain (angina). Each of these negative inotropes works in each of their ways.
These drugs act to “block” the effects of adrenaline on your body’s beta receptors, which then slow the nerve impulses that travel through the heart. Because of such, the patient’s heart does not have to work as hard because it needs less blood and oxygen.
These are usually given to address high blood pressure, heart attack, chest pain and irregular heart rhythm.
- Calcium channel blockers
These drugs slow the rate at which calcium passes into the heart muscle and into the vessel walls, which then results to relaxation of the vessels. The relaxed vessels then let blood flow more easily through them, thus lowering blood pressure.
These are usually used in treating high blood pressure, chest pain, and irregular heart rhythm.
- Anti-arrhythmic medicines
In simple words, these medicines slow the electrical conduction in the heart.
As nurses going on duty, we are not only responsible for administering ordered medications and infusions, part of our responsibility also includes knowing the actions and indications of the drugs that we are administering including possible side effects that it may bring. Like doctors, we are professionals too and we have studied about drugs way back during our college years. Let us not just be dependent on doctors alone, let us also practice our part as well as act as professionals and active members of the health care team.