What potential toxic effect may occur from an overdose of isocarboxazid?

An overdose of isocarboxazid, which is a monoamine oxidase inhibitor (MAOI) used primarily in the treatment of depression, can lead to significant complications due to its pharmacological effects on the nervous system and cardiovascular system. One of the potential toxic effects from an overdose is circulatory collapse.

Circulatory collapse can occur because isocarboxazid can cause hypertensive crises when taken in excessive amounts or when combined with certain foods or other medications. This hypertensive response is linked to the buildup of norepinephrine, leading to severe spikes in blood pressure, which ultimately may overwhelm the vascular system. As the body's compensatory mechanisms fail to regulate blood pressure, this can lead to a state where circulation is compromised, resulting in decreased blood flow to vital organs and potentially precipitating shock or collapse.

Understanding the pharmacodynamics of isocarboxazid is essential, as it helps to underline how the drug's action can impact cardiovascular stability. Monitoring for signs of circulatory problems is critical in patients taking MAOIs, especially during dose adjustments or in the case of overdose.