Paracetamol, unlike other common analgesics such as
aspirin and
ibuprofen, has relatively little
anti-inflammatory activity, and so it is
not considered to be a
non-steroidal anti-inflammatory drug (NSAID).
...
One theory holds that paracetamol works by inhibiting the
COX-3 isoform of the cyclooxygenase family of enzymes. This enzyme, when expressed in dogs, shares a strong similarity to the other COX enzymes, produces pro-inflammatory chemicals, and is selectively inhibited by paracetamol.
[27] However, some research has suggested that in humans and mice, the COX-3 enzyme is without inflammatory action.
[17] Another possibility is that paracetamol is able to block cycloxygenase as in aspirin, but that in an inflammatory environment, where the concentration of peroxides is high, the oxidation state of paracetamol is high which prevents its actions. This would mean that paracetamol has no direct effect at the site of inflammation but instead acts in the CNS to reduce temperature etc where the environment is not oxidative.
[27] The exact mechanism by which paracetamol is believed to affect COX-3 is still disputed by some research.
Afaik. 