A patient with organophosphate poisoning is being treated with atropine. The nurse notes that the pupil size has returned to normal but the patient still has profuse bronchial secretions. What is the correct interpretation of this finding?

• A Atropine dose is adequate; bronchial secretions are not muscarinic-mediated
• B Pupil size is not a reliable endpoint for atropine therapy; bronchial secretion control is the correct endpoint ✓
• C Additional oxime therapy should be started to address bronchial secretions
• D Atropine only works on iris sphincter; a different anticholinergic is needed for lungs

Explanation

In organophosphate poisoning, the clinical endpoint for atropine adequacy is drying of bronchial secretions and improvement of bronchospasm, NOT pupil dilation. Pupils may dilate with relatively low doses due to high sensitivity of the iris, whereas the bronchial glands require higher atropine doses. Relying on mydriasis as the endpoint risks undertreating pulmonary complications, which are the primary cause of death.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

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Written and medically reviewed by the StethoPrep medical team.