What do we (not) know about how paracetamol (acetaminophen) works?

WHAT IS KNOWN AND BACKGROUND

Although paracetamol (acetaminophen), N-(4-Hydroxyphenyl)acetamide, is one of the world's most widely used analgesics, the mechanism by which it produces its analgesic effect is largely unknown. This lack is relevant because: (i) optimal pain treatment matches the analgesic mechanism to the (patho)physiology of the pain and (ii) modern drug discovery relies on an appropriate screening assay.

OBJECTIVE

To review the clinical profile and preclinical studies of paracetamol as means of gaining insight into its mechanism of analgesic action.

METHODS

A literature search was conducted of clinical and preclinical literature and the information obtained was organized and reviewed from the perspective of its contribution to an understanding of the mechanism of analgesic action of paracetamol.

RESULTS

Paracetamol's broad spectrum of analgesic and other pharmacological actions is presented, along with its multiple postulated mechanism(s) of action. No one mechanism has been definitively shown to account for its analgesic activity.

WHAT IS NEW AND CONCLUSION

Further research is needed to uncover the mechanism of analgesic action of paracetamol. The lack of this knowledge affects optimal clinical use and impedes drug discovery efforts.

Parents' decision following the Food and Drug Administration recommendation: the case of over-the-counter cough and cold medication

BACKGROUND

In 2007, the Food and Drug Administration (FDA) recommended against parents administering over-the-counter cough and cold medications (OTC-CCM) to children under 2 years of age because serious and potentially life-threatening side effects can occur. This study examined the impact of FDA's recommendations against giving children under 2 years old OTC-CCM.

METHODS

We asked parents (n= 377) whether they knew of and trusted the FDA recommendations, as well as whether they intended to follow them. We also examined parents' knowledge, perceptions and behaviours with respect to OTC-CCM.

RESULTS

About 33% of our sample had never heard of the FDA recommendations. Of those who were aware, 32.9% intended to continue administering OTC-CCM, and another 36.7% were not sure what to do. Our results indicate that parents who trust the FDA recommendations are significantly more likely to stop giving OTC-CCM to their children. However, almost half did not trust the FDA recommendations or were not sure whether to trust them. Our results indicate that parents who trust the FDA recommendation are significantly more likely to discontinue using OTC-CCM. Our data also reveal that many parents give more than one drug simultaneously (32.9%), cannot identify the active ingredient(s) (28.9%) or fail to store the medications in a safe place (86.1%).

CONCLUSION

Parents' confidence in the FDA recommendations predicted whether they would continue or stop administering OTC-CCM to their children. Our findings illustrate the urgent need for widespread public education about OTC-CCM products to ensure children's safety.