Strophanthin

Strophanthin is a cardiac glycoside derived from the seeds of certain African plants belonging to the genera Strophanthus and Acokanthera. It has been historically used for its potent effects on the heart, particularly in the treatment of heart failure and certain types of arrhythmias.

History

Strophanthin was first isolated in the late 19th century and was used as a cardiotonic agent. It was particularly noted for its rapid onset of action when administered intravenously. The use of strophanthin has declined with the advent of more modern cardiac medications.

Chemical Composition

Strophanthin is a complex molecule that belongs to the class of cardiac glycosides. These compounds exert their effects by inhibiting the sodium-potassium ATPase pump, leading to an increase in intracellular calcium concentrations in cardiac muscle cells. This results in increased force of contraction of the heart muscle.

Medical Uses

Strophanthin has been used in the treatment of:

• Heart failure
• Certain types of arrhythmias

However, due to its narrow therapeutic index and the availability of safer alternatives, its use in modern medicine is limited.

Mechanism of Action

Strophanthin works by inhibiting the sodium-potassium ATPase pump, which leads to an increase in intracellular sodium levels. This, in turn, affects the sodium-calcium exchanger, leading to an increase in intracellular calcium levels. The increased calcium enhances the contractility of the heart muscle.

Side Effects

The use of strophanthin can lead to several side effects, including:

• Nausea
• Vomiting
• Diarrhea
• Arrhythmias
• Electrolyte imbalance

Toxicity

Strophanthin has a narrow therapeutic index, meaning the range between an effective dose and a toxic dose is small. Symptoms of strophanthin toxicity include severe arrhythmias, gastrointestinal distress, and electrolyte imbalance.

Related Compounds

Strophanthin is related to other cardiac glycosides such as digoxin and ouabain, which are also used to treat heart conditions but have different pharmacokinetic properties.

See Also

• Cardiac glycoside
• Heart failure
• Arrhythmia
• Digoxin
• Ouabain