Which of the following substances is categorized under Schedule A poisons?

Digitalis is categorized under Schedule A poisons due to its significant toxicity and potential for abuse. Schedule A poisons are those substances recognized for their dangerous nature and are subject to strict regulations regarding their dispensing and usage. Digitalis, derived from the foxglove plant, contains compounds that can lead to severe cardiac effects, making it essential for health professionals to exercise caution when prescribing or handling this medication.

When it comes to the other substances listed, gingko biloba is generally regarded as safe and is often used as a dietary supplement; thus it does not fall under stringent scheduling. Atropine and belladonna are also toxic but their classifications may differ based on specific state regulations. Belladonna contains atropine, which is a toxic alkaloid, but it is not necessarily considered within the same regulatory framework as Digitalis when it comes to Schedule A classifications.

Understanding the categorization of substances into schedules helps manage their use to ensure patient safety and reduce the risks associated with toxic medications.