After a tribal raid with only 3 raiders(early in game). he had some cuts and was receiving medicine when i checked he was on doctor treatment only.
The prisoner was in a 1x7 room in a sleeping SPOT
Maybe the medicine was used for a medical operation?
Could be related to this bug: https://ludeon.com/mantis/view.php?id=2383 (https://ludeon.com/mantis/view.php?id=2383)
No more info, closing.