Is the Largely used Analgesic Paracetamol without any Adverse Effects? A Study on Ants as Models

The nowadays most used analgesic is paracetamol. Its mode of action is not yet elucidated and its adverse effects have been only partly studied. In the present work, using ants as models, we examined the potential effect of a large dose (4g per day) on 22 physiological and ethological traits. It appeared that paracetamol increased the ants’ sinuosity of movement, decreased their orientation ability, trail-following behavior, tactile (pain) perception, cognition, visual and olfactory conditioning as well as memory. It did not affect the ants’ food consumption, general activity, audacity, brood caring, aggressiveness against nestmates and aliens, as well as ability in escaping from an enclosure. Paracetamol impacted thus some traits depending from the central nervous system. On the basis of other researchers’ studies, it can be advanced that such an impact depends on the consumed dose. Ants presented slight adaptation, as well as a significant habituation to paracetamol, two traits which are unfavorable to this drug use. Moreover, ants developed some dependence on paracetamol, and the effect of this drug rapidly decreased after weaning, nearly vanishing in about 4 hours. We suggest some control and limitation of usage as for the access to and the use of paracetamol. Note also that pain perception is a vital function and continuously inhibiting it may imperil the health.