Trump is a classic snake oil salesman, although snake oil would be much less dangerous than his prescriptions. He belongs to a tradition of quacks and charlatans peddling dangerous medical nonsense. That tradition, sad to say, has flourished in the USA since colonial times.
Historically, orthodox medical practitioners have offered remedies just as dangerous and useless as those of the quacks. Until the late 19th century, bleeding and purging were mainstays of their practice, and their drugs often included toxic ingredients. Critics of standard medical practice loved to claim that doctors were more dangerous than the diseases they treated. English artist/engraver William Hogarth lumped fashionable doctors and famous quacks together and called them "The Company of Undertakers." (1736)
Another English artist Thomas Rowlandson, among others, saw little difference between the orthodox doctors and the quacks. (Below: Rowlandson, "Death and the Apothecary, or the Quack Doctor," from the English Dance of Death, 1815-1817)
Along with heavy bleeding Rush recommended drastic purging with large quantities of jalap, a powerful herbal cathartic, and calomel -- mercuric chloride. Rush declared that his remedies were beneficial for all manner of diseases. He called his system “heroic" medicine. The patients who survived it surely must have been heroic. Calomel became a mainstay of 19th century medicine, especially in America.
From the 16th century into the early 20th, compounds of the heavy metal mercury were used to treat a wide variety of illnesses. The 16th century German physician Paracelsus promoted mercury as a specific in the treatment of syphilis. Mercury continued to be the medicine of choice for that disorder until the early 20th century. Its use gave rise to the saying “One night with Venus and a lifetime with Mercury.” Joking aside, the effects of ingesting mercury can be frightful. They include loss of teeth, rotting of the jaw, paralysis, and death.
Other highly toxic minerals were common in patent and proprietary remedies, especially arsenic and antimony. In the mid-18th century, Dr Robert James patented his famous fever powders, a concoction of oxide of antimony and calcium phosphate. Dr James’ Fever Powders remained a popular remedy well into the 20th century.
In the early 20th century, the German scientist Paul Ehrlich developed arsenic compounds that were widely used to treat syphilis until penicillin became available in the 1940s.
Even young children could purchase these dangerous chemicals, as this Punch cartoon of 1849 points out. The young girl buys "lodnum" and arsenic "for the rats" on behalf of her "mother."
Godfrey’s Cordial, a favourite remedy for teething or sleepless children, was a mixture of laudanum and treacle. Laudanum is a tincture of opium, which has been used medicinally since ancient times. Treacle is a sweet sugar syrup, which made the concoction tasty to kids. They lapped it up and slept ever so well. Godfrey's Cordial and its imitators was a mainstay of the Industrial Revolution, great for mothers condemned to work 12 hours a day, 6 days a week in a factory. Not so good for the little ones, who often developed addiction and all sorts of physical and mental problems. The ad below is for a version of the cordial.
Opium in various forms was a standard ingredient in many patent and proprietary medicines from the 17th to the 20th centuries, often mixed with alcohol. It was mixed with ipecac in Dover’s Powders, which remained for sale in many places into the 1960s. When morphine, an opium derivative, was discovered in the early 19th century, it was hailed as a miracle pain killer. It is still in use for extreme pain, though carefully controlled. It was so readily available and widely used in the late 19th century that morphine addicts became a regular feature of literature.
In the 1890s, the Bayer Co. in Germany came up with a solution to the morphine problem: heroin, another opium derivative. They hailed it as another miracle drug, for many disorders. We know how that turned out.
In the early 20th century many countries began to regulate and limit the sale and use of opiates and other drugs, such as cocaine. But toxic ingredients continued to be used in some patent and proprietary medicines. And as Trump's medical pronouncements make clear, quackery in medical advice can flourish at the highest levels of society and government.