How quickly should Metacam take effect?

Boris had his first full dose today and I'm just wondering when I should start seeing results? I think he's perked up a bit already but I'm not sure it's helped much with the sneezing/inflammation in nasal passages as of yet.

The peak plasma levels (i.e. when the maximum level of drug is in the bloodstream) aren't reached for 6 to 8 hours
http://wildpro.twycrosszoo.org/s/00Chem/ChComplex/Meloxicam.htm
but the analgesic effect kicks in much much sooner. I would think if you are going to see an improvement you should see it within the first 24 to 48 hours.