Medical records of some patients were destroyed in an arson attack which also cost the NHS £7,000 when a power loss meant drugs meant for immunisation could not be used, a judge was told.

It all happened after 30-year-old patient Sion Griffiths, upset that he had not been able to get the diazepam he craved, broke in during the night and started a fire to hide the evidence after he bled when smashing a window.

It happened at the surgery at Gwalchmai, Anglesey, which has 2,500 patients and also serves surrounding villages.

Griffiths, who lived at Maes Meurig, close to the surgery, pleaded guilty to burglary and arson and was jailed for two years and four months, with an extended licence period of three years at the end of the sentence.

Judge Huw Rees at Caernarfon crown court praised the efforts of Dr Richard Keatinge, who had rushed from his home and fought to put out the flames in the early hours of May 5, “at some obvious risk to himself.”

Elen Owen, prosecuting, said when he arrived at the surgery he spotted Griffiths trying to hide outside. “The manager’s office window had been smashed and there was smoke billowing,” said Miss Owen. Dr Keatinge had borrowed a hose from a neighbour and managed to get the fire out, having also called the fire brigade.

Three or four boxes of diazepam had been stolen and two office chairs and paperwork set ablaze.

Miss Owen said the result of the power loss was that immunisation had to be cancelled for a week.

Griffiths had 29 previous offences, including for criminal damage in 2008 at a surgery a few miles away when slates had been torn from the roof. In 2011 he had started fires at two houses near his home and also to a tractor and had been jailed for three years.

Gareth Roberts, defending, said Griffiths had never recovered from personal tragedies, losing his father when he was four, his stepfather when 16, and two of his friends in a car crash when he was 14.

“He’s ashamed and profoundly remorseful,” said the barrister.

“His intention was to steal the medication he craved.”

When his sentence was completed he hoped to start a landscape gardening business.

Passing sentence, Judge Rees said reports from a psychiatrist and the probation service suggested that Griffiths posed a significant risk when under the influence of drink or drugs.

He had targeted the surgery deliberately because “you wanted those drugs which you had been quite properly denied earlier that day.”   

After the case Detective Constable Matt Corkish said: “Griffiths is a prolific offender with a track record of both burglary and arson  and so today’s sentence is significant for both his latest victims and the communities of Anglesey.”

He added: “Anglesey and north Wales is a far safer place with Griffiths behind bars.”