Fabrizio Sanna and colleagues at the University of Cagliari in Italy injected oxytocin into particular parts of the brains of rats and induced yawning, or blocked the effect by injecting an oxytocin-blocking chemical first.

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Garret A. FitzGerald, a pharmacologist at the University of Pennsylvania, raised the first red flags about pharmaceuticals like Vioxx, Celebrex and Bextra after he saw chemical reasons that the drugs, which all inhibit inflammation by blocking the same enzyme, might cause heart attacks.

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It works similarly to many pesticides, by blocking the breakdown of acetylcholine, a major neurotransmitter, leading to a rapid buildup of this chemical in the body.

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