A 29-month-old boy was in critical condition after being injected with six times the prescribed dosage of a heart medication at the Prince of Wales Hospital in Sha Tin, the New Territories last month.

The boy, who has a pre-existing heart condition, was admitted to the emergency room of the Prince of Wales Hospital at 7:30pm on September 30, suffering from fever and difficulty in breathing, Apple Daily reported, adding that his heartbeat reportedly dropped to 51 beats per minute.

Pediatricians on duty prescribed 0.26mg of atropine, which is used to treat patients with slow heartbeats. However, after he received the injection, the infant’s condition further deteriorated and he fell into a coma.

After a round of resuscitation, the boy was revived and received treatment in the pediatric intensive care unit before being transferred to Queen Mary Hospital.

Upon checking his medical record, a nurse at the Prince of Wales Hospital discovered that 1.56 milligrams of the drug was injected – six times the prescribed amount.

It is suspected that the Atropine kept in the Prince of Wales Hospital is in a higher concentration, and that staff failed to take that into consideration.

Doctors in Queen Mary Hospital diagnosed an inflammation of the heart muscle and a respiratory viral infection. He remains in critical condition.

A hospital spokesman said the overdose of atropine might not be the cause of the boy’s condition as his heartbeat did not become faster, Apple Daily reported.

The hospital apologized for the error and said that a panel would be set up to further investigate the incident.