General discusson on use of analgesics

The bullet points on this page are an informal compilation of opinions of contributors to the online VOLE List. As such, they are not peer reviewed and may contain differences of opinion. Those wishing to contact the list may contact Adrian Smith.

• In my experience, in commercial drug development work, the main worries have been with the incidental use of NSAIDs for clinical purposes in long term studies with "immunomodulator" test materials. The point of friction is usually at the interface with the client rather than with internal stakeholders. In my experience again, this has always been managed properly, even at the expense of the client relationship. Obviously there are potential interferences with many other study types, but clearly defined humane end points seem to deal with most of these adequately.
• Yes we've experienced reluctance for researchers to give opioid pain relief to mice in an inflammation model "because it has immune-modulating effects and might alter the experiment" (no evidence provided) and also that "there's nothing in the literature about pain relief in this model". We pointed out that pain also has immune modulating effects, the issues of accuracy in reporting and the need to apply 3Rs but to no avail... The techs are currently scoring mice (with the Mouse Grimace Scale) through this recent experiment and we'll regroup with this information. At the risk of being controversial, it does seem that the onus is usually on the "welfare end" to provide evidence that a refinement won't mess up the experiment, whereas surely the opposite should be the case, that the burden should lie upon the PI to show the robust scientific evidence that applying such a humane refinement to a technique is not possible for whatever reason.
• Regarding pilot studies, my approach has always been that analgesia must be used by default, so if they don’t currently have evidence to show that they can’t study that question with analgesia, they need to set up analgesia vs no analgesia in order to provide an evidence base (unless it’s a pain study). I do find the severity limits unhelpful though. How a surgical study with no analgesia can be moderate just because it’s a rodent makes no sense to me (since when did we have evidence that their experience of pain was less detrimental than that of a monkey).  I have known researchers use the severity limit as evidence that analgesia isn’t needed (in good faith, i.e. they genuinely don’t believe rodents need analgesia and believe that’s supported by the view that the work is moderate).
• Bio-Serv has a range of bacon-flavoured analgesic tablets. See also: Use of Flavored Tablets of Gabapentin and Carprofen to Attenuate Postoperative Hypersensitivity in an Incisional Pain Model in Rats (Rattus norvegicus).
• The fact that pain itself has a myriad of uncontrolled side effects seems to be ignored.  Sometimes on the basis of the need to compare with historical results. With this argument.of course, nothing changes.  Alternatively, we can use that argument as a scientific rationale for trying both methods (with and without analgesia) to see which give the more consistent results.  If the results are different an explanation has to be found? The ethical argument is that of the precautionary principle in that if we err on the side of caution (try to promote better welfare) and are wrong LESS harm is caused than not going for better welfare.  If we assume that animals are not in pain and they are, not doing anythings will result in a greater harm. The North American argument has been going on for decades and revolves who has to prove what. You prove to me that the animal is in pain and I will use analgesics (etc). You prove to me the animal is not in pain and I will forego analgesia. The assumption that an animal is in pain and to provide analgesia is to err on the side of caution as less harm will result and so is the best ethics. (Assuming one agrees that pain is a harm).