A hospital patient was given a "significant" overdose of an anti-epileptic drug with a coroner warning masks worn by doctors "aggravated" the miscommunication.

Fifty-six-year-old John Skinner died at Watford General Hospital in May 2020 after being admitted following an epileptic seizure.

An inquest heard after suffering another seizure upon arrival, a junior doctor sought advice on how much phenytoin - a drug used to control epileptic seizures - to give Mr Skinner and misheard 15mg/kg as 50 mg/kg.

The usual phenytoin to treat epilepsy, as set out on the NHS website, is between 200mg and 500mg a day for adults.

The assistant coroner for Hertfordshire, Graham Danbury, said Mr Skinner was given a 3,600mg dosage and he suffered a cardiac arrest within 16 minutes. Doctors were unable to revive Mr Skinner and he died.

Following the conclusion of an inquest on November 4 2021, Mr Skinner's cause of death was listed as acute cardiac failure and phenytoin toxicity.

On February 10, Mr Danbury submitted a Prevention of Future Deaths Report to the chief executive of the NHS saying he feared the same type of error could happen at other hospitals if action was not taken.

He wrote: "As a result of a failure in verbal communication between the doctors, aggravated as both were masked, a dose of 15 mg/kg was heard as 50 mg/kg and an overdose was administered."

He added: "The junior doctor instructed to administer phenytoin did not know the required dosage and asked his more senior colleague for advice. The senior doctor's reply 15kmg/kg was heard by the junior doctor as 50mg/kg resulting in administration of a significant overdose.

"This is a readily foreseeable confusion which could apply in any hospital and could be avoided by use of clearer and less confusable means of communication and expression of number.

"In my opinion action should be taken to prevent future deaths and I believe you NHS England have the power to take such action."

NHS England told the BBC it would respond to the coroner by April 12.

A spokesperson for West Hertfordshire Hospitals NHS Trust, which runs Watford General, said: "A comprehensive action plan is in place to ensure that lessons are learned from this incident."