^^ there's no need to worry about self-incrimination when referring to personal use. If you do want the post edited, just click on the report post button to ask a moderator for help.
I don't know if there is any evidence, but I do find opioids
and many other drugs
to be enhanced a little when used in combination with a small amount of caffeine
(such as a cup of coffee
or a can of cola). I'm not aware of any alarming possible interactions, although both opioids including tramadol
and caffeine may have an impact on blood pressure.
Diaz-Reval et al (2010) suggest there is an antinociceptive (reduction in pain sensitivity) effect of tramadol and caffeine administered separately or in combination. Synergistic and antagonistic effects may be possible, making tramadol and caffeine a useful combination in pain management. During recovery from surgery I noticed that caffeine improved the analgesic effects of opioids including heroin
Tramadol and caffeine produce synergistic interactions on antinociception measured in a formalin model.
DŪaz-Reval MI et al. Behav. 2010 Dec;97(2):357-62. doi
: 10.1016/j.pbb.2010.09.004. Epub 2010 Sep 15.