Medications that are provided on prescription are chosen, approved and dispensed by pharmacies because they are believed to be the treatment that is the most effective whilst being as safe as possible.
This is why drug discovery takes so long and is so expensive; it is not enough to find a drug compound but it needs to be rigorously tested first in laboratory conditions before multiple clinical trial stages for dosage and efficacy, as well as short-term and long-term safety.
Even after it has been approved for use, it will continue to be monitored and there is a Yellow Card Scheme that allows medical professionals and patients to report adverse side effects, which has led to certain popular medications being withdrawn from the market on safety grounds.
Typically, when a drug is withdrawn, that is the end of the story. It will often receive some modicum of research but it is typically seen as a dead end.
However, some medications that were previously banned have been sold again, and there are some rather interesting reasons why this is the case.
Fenfluramine
An appetite suppressant introduced in 1963, fenfluramine was relatively effective at helping to treat obesity, but its greatest success was the very reason it was withdrawn from the market.
It was found in the 1980s that combining it with phentermine made it far more effective at suppressing appetite and helping people to lose weight, but in 1997 both were withdrawn from the market for being linked to faulty heart valves.
For over 20 years, it remained banned until it was found to be effective at treating Dravet syndrome, a serious and violent form of treatment-resistant epilepsy that can also be treated with medical cannabis.
Thalidomide
One of the most controversial medicines of all time, thalidomide was originally sold over the counter as a treatment for morning sickness, only for it to be found that it caused severe, life-threatening birth defects.
The testing and clinical trials undertaken at the time were inadequate for ascertaining the risks to pregnancies, and the result was that the medicine was withdrawn from any country it was sold in, and a £20m settlement was paid to the victims.
It looked like thalidomide’s lasting legacy would be the people it harmed and the lessons hopefully learned by the industry, but in 1964 a somewhat unexpected turn of events turned it into the only medication that could help.
In 1964, a patient was visited by Jacob Sheskin who was seriously ill with leprosy. He was suffering from the painful skin condition erythema nodosum leprosum, a complication of leprosy that caused chronic pain and disability.
Dr Sheskin managed to get approval to try thalidomide to treat the condition and it helped the patient sleep and get up without help after resting.
It took until 1998 for thalidomide to be approved again, and only under very strict conditions controlling its use in order to keep people safe and avoid a repeat of what happened when it was first approved and later in Brazil in the 1960s.