While most medications are a mystery to most audiences, there are a few whose native source is more familiar. Willow bark as a precursor to aspirin, or bread mold as that of penicillin, are the usual examples; others, such as poppy extract for a sedative, are more obscure, but still recognizable to viewers who take an interest.
Therefore, in order to show that a primitive healer, herbalist, or apothecary is genuinely skilled, not ignorant or a fraud, they're shown administering one of these (very) few recognizable proto-drugs to patients in need. Never mind that an historical physician of the era may not know about the medicine in question, or be capable of extracting the active substance from its raw state, or that another, little-known remedy from the period might be safer and more effective: it's always the treatment audiences will recognize that gets used.
Can be an example of Viewers Are Geniuses
, for the more obscure remedies. Does not apply to fictional medications or recreational stimulants, as use of such drugs does not demonstrate legitimate medical know-how.
- Disney's Pocohontas has Pocohontas give John Smith willow bark for the pain after he is shot in the side.
- This is done in the Circle Of Magic series even to the point of actually using willow bark tea by name for headaches and fevers and the like. At one point there is an epidemic and very modern steps to quarantine the disease and develop treatments through experimentation are undertaken. Somewhat justified in that magic has allowed people in that universe to be much more knowledgeable about the mechanics of the world.
- In one of the Lord Darcy stories, an elderly herb-woman uses a bread-mold poultice to treat wounds, suggesting she's using penicillin as an antibiotic. Subverted in that it gets her into trouble with the real professional healers, who use magic to treat wounds and can't be having with such superstitious remedies.
- The moldy bread poultice is one of Magrat Garlick's specialties in the Discworld series.
- In Carpe Jugulum, Magrat also makes willow bark tablets. It also gets mentioned in Hogfather:
Bursar: Willow bark.
Senior Wrangler: That might work. It's an analgesic.
Ridcully: Well, possibly, but he might be better putting it in his mouth.
- Cadfael is all over this. He was a soldier in the Crusades, and he's an apothecary in his monastic community. Lavender for headaches (The Price of Light), poppy extract, and so on.
- In the Earth's Children series it's mentioned that practically everybody knows about willow bark tea, even non-healers.
- In the Garrett, P.I. fantasy/noir series, Dean brews willow-bark tea for Garrett after nights of heavy drinking.
- In the novel Outlander, Claire Beauchamp demonstrates even more knowledge when she comments that willow bark tea can make bleeding take longer to stop while discussing the healing properties of herbs with the keeper of Castle Leoch's herb garden.
- In A Song Of Ice And Fire, maesters (essentially doctors, though they have other duties) commonly prescribe "milk of the poppy" (that is, opium) to anyone suffering from a particularly painful injury.
- In Lois McMaster Bujold's The Hallowed Hunt, Ingrey was given a pain-reliving medication made from poppies (among other things).
- There is an episode of Dinosaurs in which the baby gets seriously ill and the family spends lots of money on fancy new medicines. When those fail, they go to a healer who lives in the woods, who cures the baby with moldy bread.
- In one episode of Queen Of Swords almost everybody in the village gets sick; the Mighty Whitey doctor doses them with a practically magical healing elixer, which he later reveals is made from willow bark.
- Dr. Quinn, Medicine Woman was always prescribing willow bark tea.
- When Jacques Cartier and his men where spending the winter in the region which is now Canada, they came down with scurvy until the natives showed them out to use the bark of certain trees to make a brew to cure them. Future research would prove that the tree bark in question contains high levels of Vitamin C.