digitoksin

Digitoxin is a cardiac glycoside found in the leaves of the foxglove plant (Digitalis purpurea). It is structurally similar to digoxin, another well-known cardiac glycoside. Digitoxin has been used historically in medicine for its ability to strengthen the force of heart contractions and slow the heart rate. This makes it useful in the treatment of certain heart conditions, such as congestive heart failure and atrial fibrillation.

The mechanism of action for digitoxin involves inhibiting the sodium-potassium ATPase pump in heart muscle cells. This leads to an increase in intracellular sodium, which in turn promotes calcium influx into the cell. The increased intracellular calcium enhances the contractility of the heart muscle. Additionally, digitoxin can affect the electrical conduction system of the heart, slowing down the transmission of impulses through the atrioventricular node.

Due to its narrow therapeutic index, digitoxin has a significant potential for toxicity. Symptoms of digitoxin toxicity can range from gastrointestinal disturbances like nausea and vomiting to more severe cardiac arrhythmias and neurological effects such as confusion and visual disturbances. The elimination half-life of digitoxin is longer than that of digoxin, meaning it stays in the body for a longer period. Consequently, it requires careful monitoring and dosage adjustment to ensure patient safety. While its use has declined with the advent of newer medications, digitoxin may still be considered in specific clinical situations or when other treatments are ineffective.