Marked suppression of ventilation while awake following massive ingestion of atenolol

We describe a patient who ingested 5 g of atenolol with ethanol. After awakening, with repeat toxicology screen only showing atenolol, and in spite of normal voluntary breathing mechanics, he had marked suppression of his spontaneous respirations as measured by minute ventilation and by occlusion pressure with no incremental response to hypercapnic challenge. Subsequently, he recovered. Although we are unable to prove a causal relationship, future patients with atenolol overdose should be observed carefully for ventilatory failure, even if fully conscious.