A 27-year-old pharmacist has been cleared of manslaughter after a terminally ill cancer patient died from a prescription of morphine that was 10 times stronger than it should have been.

Phillip Dean had been accused of failing to read a doctor’s instructions carefully and handing over 100mg of Oramorph instead of 10mg.

Critically ill Arthur Thomas, 84, died soon after he was given the lethal dose at his home in Hythe by his grandson.

The prosecution asserted at Maidstone Crown Court that because Mr Dean did not make sure that what he was dispensing was intended by the doctor, he was grossly negligent.

Mr Dean, of Mitchell Avenue, Hawkinge, near Folkestone, was working at Eakins Chemist in Hythe High Street when he was given the prescription in April 2005.

Mark Fenhalls, prosecuting, said although Mr Thomas’s illness was terminal, it was not relevant as far as the case was concerned.

He was diagnosed with liver cancer in January 2005 and his health deteriorated. He at first took Codeine, but it was not strong enough to relieve the pain.

On April 23, a nurse visited him and then spoke to a doctor. Oramorph was then prescribed.

The jury was shown the prescription which, said Mr Fenhalls, instructed that 10mg be taken in 5ml.

"At the heart of this case is the action Mr Dean took when he read that line," said the prosecutor. "On the face of it, he appears to have interpreted it wrongly as being 100mg per 5ml."

Mr Thomas’s grandson Tony Poole collected the prescription from the chemist on April 25. Mr Dean gave him two boxes, each containing 20 doses of Oramorph. One was of 10mg strength and the other 100mg.

"He asked how to administer it," said Mr Fenhalls. "Critically, perhaps, Mr Dean never warned Mr Poole that there were two different doses of morphine he supplied."

That night, Mr Poole gave his grandfather one of the stronger doses. "That dose, we say, was the one that killed him," said Mr Fenhalls. "He lapsed into unconsciousness that night and died on April 27."

Mr Dean, who denied manslaughter, embraced family members after the jury of six men and six women returned a not guilty verdict.

He told the court there was no doubt in his mind that there was anything wrong with the prescription or that he was doing anything improper.