An elderly man suffered stabbing pains after being given the wrong tablets for his heart condition.

Michael Lewry, 67, took the medication for a week before realising his chemist had blundered.

Mr Lewry is forced to take daily medication for angina after a heart attack in 1991.

An investigation is now being carried out into how the wrong drugs ended up in the pensioner's prescription.

He suffered stabbing pains in his arms and legs and feared he might have died.

The retired carpenter, of South Road, Newhaven, said: "I was in agony with severe pains in my arms and legs."

The mistake occurred when Mr Lewry renewed his prescription for the angina drug atenolol at Chapel Street Chemists in Newhaven on February 8.

The correct label with instructions for atenolol was stuck on a box of thyroxine tablets, taken for thyroid gland problems.

Mr Lewry, who lives alone, started his new tablets on February 14 and only realised the mistake seven days later when he fell ill.

He said: "I went to the health centre and they took one look at the box and rushed me in to see a doctor."

The GP contacted experts at the Royal Sussex County Hospital in Brighton for advice on possible side effects.

Mr Lewry was given the all-clear but left badly shaken.

He said: "The pharmacy made a very serious mistake and I was practically in tears when I went to see them.

"They couldn't apologise enough, saying it would never happen again."

After complaining, Mr Lewry received a written apology from Newhaven Pharmacies, owners of the chemists.

The letter from pharmacist Mark Heard said: "We are now making a written reply offering our apologies for the error that occurred when your prescription was dispensed.

"We confirm an investigation will follow and that procedures will be further reviewed to ensure a similar error does not occur again."

Mr Heard was unable to discuss the case with The Argus for reasons of NHS confidentiality.

He said: "If and when errors do occur in dispensing, every effort is made to find the cause and prevent it reoccurring."

A spokeswoman for East Sussex, Brighton and Hove Health Authority said: "The authority is in touch with the pharmacist to ensure appropriate dispensing and checking procedures are in place."