A RETIRED pharmacologist has recalled how he nearly died after accidentally taking ten times the intended dosage of a drug to treat asthma.

In the late 1960s Dr Richard Marshall, 73, put himself forward as a human guinea pig to trial the then untested medication salbutamol, which almost killed him.

Salbutamol is widely used today to relieve breathlessness in asthma sufferers, but in 1968 it was little more than an experimental substance.

As a fresh-faced 22-year-old pharmacology graduate in 1968, Mr Marshall was one of three volunteers in the first ever human safety trial was ready to be trial on patients.

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Salbutamol was patented in Britain in 1966 before it became commercially available across the UK in 1969.

Mr Marshall and two senior chemist colleagues employed at the small Hertfordshire pharmaceutical firm, Allen & Hanburys, were given steadily increasing doses of medication and a control substance over three days.

The trial was intended to make sure the drug worked as expected by stimulating the lungs without affecting the heart.

Dr Marshall, from Falkirk, said: "I was the first person in the world to take salbutamol.

“That was just chance, because of where my bed was positioned during the trial.

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"These were the days before health and safety - I don't think they'd be allowed to do it now.

“But we were supposed to be getting two milligrams, four milligrams and eight milligrams over three successive days, and they would measure blood pressure and heart rate.”

On the final day of the trial things took a frightening turn when Dr Marshall was accidentally given a massive 80 milligrams instead of eight.

As a result, his heart started racing and his blood pressure dropped sharly.

Dr Marshall said: "But things didn't go right on the last day because we were supposed to be getting eight milligrams of salbutamol but the pharmacist made a mistake in her weighing and gave us 80 milligrams by accident.

"Alarm bells began to ring almost straight away.

“My heart was pounding and of course it wasn't supposed to touch the heart - but 80 milligrams was a massive dose.

"Our blood pressure started falling away.

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"That was quite hairy."

Allen & Hanburys, which had been taken over by Glaxo a decade earlier, was better known for medicinal pastilles and cod liver oil.

But it was another Scot - Sir David Jack, a coal miner's son from Fife - who pioneered the development of salbutamol as the company’s director of research.

As the overdose crisis unfolded, Sir David was telephoned at his London headquarters.

Dr Marshall said: "Sir David came rushing up from Bethnal Green in his chauffeur-driven car to find out what the hell was going on.

"This was his two best chemists and a newly-recruited young Scottish pharmacologist who were now in some danger.

"He arrived - this was the first time I'd ever met him - and took charge of proceedings.

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“When things looked a bit dodgy he decided to stop that part of the trial and gave us each a beta-blocker.

“That quickly reversed the side effects."

With the safety trial complete, salbutamol went on to patient clinical trials and in 1969 it revolutionised asthma treatment when it launched under the brand name Ventolin.

It proved to be a major commercial success and, 50 years on, remains the world's most used asthma drug.

Dr Marshall said: "For that trial we got £30 Boots vouchers - and Sir David got his knighthood.

"But £30 was quite a lot of money then."

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The salbutamol trial was a seminal moment in both men's careers and the beginning of a friendship that lasted until Sir David's death, aged 87, in 2011.

Dr Marshall returned to Scotland in 1971 to complete a PhD in Glasgow, followed by stints as a lecturer at Strathclyde University and a sabbatical in Canada, before being headhunted by Dutch-based pharmaceutical company Organon.

He remains proud of the contribution he and his fellow Scot made to the lives of asthma patients worldwide.

Dr Marshall said: "All through my life I've met people all over the place who suddenly bring out this blue and grey inhaler and I've met people who claim it's saved their lives.

"That makes you feel like you were part of something, and that's really nice."