What is the minimum dose of atropine that can be administered intravenously?

The minimum dose of atropine that can be administered intravenously is 0.5 mg. This dosage is significant because it is effective in managing bradycardia (slow heart rate) and can help to counteract the effects of certain types of poisoning, particularly from organophosphate compounds. Atropine works by blocking the action of acetylcholine at the muscarinic receptors, which leads to increased heart rate and reduced glandular secretions.

While other doses are possible, 0.5 mg is recognized as the lowest effective dosage for intravenous use in clinical practice. Lower doses, such as 0.1 mg, may not produce the desired physiological effects, hence are generally not used in urgent clinical scenarios.