inotropik

Inotropics are a class of drugs that alter the contractility of the heart muscle. They are primarily used to treat conditions where the heart is unable to pump blood effectively, such as heart failure and certain types of shock. Inotropics can be categorized as positive inotropes, which increase the force of myocardial contraction, or negative inotropes, which decrease it.

Positive inotropic agents work through various mechanisms. Some, like dobutamine and dopamine, stimulate beta-adrenergic receptors in the heart, leading to increased intracellular cyclic adenosine monophosphate (cAMP). This ultimately results in more calcium ions entering cardiac cells, which enhances contraction. Other positive inotropes, such as digoxin, inhibit the sodium-potassium ATPase pump, which indirectly increases intracellular calcium levels. Phosphodiesterase inhibitors, like milrinone, prevent the breakdown of cAMP, also leading to increased contractility.

Negative inotropic agents are less commonly used and are primarily employed in specific situations, such as managing hypertrophic obstructive cardiomyopathy or preventing excessive cardiac stimulation in certain arrhythmias. Beta-blockers, for example, can have negative inotropic effects by blocking the action of adrenaline and noradrenaline on the heart.

The use of inotropic drugs requires careful monitoring due to potential side effects, which can include arrhythmias, increased myocardial oxygen demand, and changes in blood pressure. The choice of inotropic agent and its dosage depend on the specific clinical condition, the patient's overall health, and potential interactions with other medications.