Atropine indications and dosing include which of the following statements?

• A. Indications: OP or carbamate poisoning; Nerve agent poisoning. Dose: 0.5–1 mg every 5–10 min
• B. Indications: OP or carbamate poisoning; Nerve agent poisoning. Dose: 1–6 mg every 5–10 min
• C. Indications: pesticide exposure; Dose: 25–50 mg
• D. Indications: cyanide poisoning; Dose: 2–4 mg

Answer: (B)

Atropine counters the muscarinic effects of excess acetylcholine seen in organophosphate and carbamate poisoning, as well as nerve agent exposure. The treatment goal is to titrate the dose until signs of atropinization appear—drying of airway secretions, bronchodilation, improved ventilation, and a faster heart rate—without overdoing it. Because these poisonings can produce significant muscarinic stimulation, starting with a moderate IV dose and repeating every 5–10 minutes is the standard approach, allowing doses to accumulate into the 1–6 mg range as needed to achieve adequate muscarinic blockade. This dosing strategy reflects the need to rapidly counteract life‑threatening secretions and bronchospasm while monitoring for response.

The other statements don’t fit as well. A smaller initial dose like 0.5–1 mg often isn’t sufficient to overcome the heavy muscarinic burden in OP or nerve agent exposures. Dosing that suggests treating pesticide exposure with a high total dose, or proposing cyanide poisoning as an indication, isn’t aligned with how atropine is used in practice. And while organophosphate pesticides are a common context, the guidance typically calls for the 1–6 mg titration range rather than a fixed, very large or very small single dose.