Medication errors do not only harm patients but also fuel the increase in antibiotic resistance, the head of the World Health Organisation (WHO) has said.

Antimicrobial resistance occurs when bacteria changes in such a way that the medication used to treat them – in this case antibiotics – becomes ineffective.

The issue has become a global one in recent years, with warnings the world could face a “post-antibiotic apocalypse” and the end of modern medicine unless the problem is addressed.

WHO director general Dr Tedros Adhanom Ghebreyesus said: “Medication errors do not only cause harm to the individual patient, they can also fuel the spread of antimicrobial resistance.

“Recently, WHO published the first report from global antimicrobial surveillance system known as GLASS, and the findings are alarming.

“In some countries up to 82% of bacterial infections are resistant to at least one of the most commonly used antibiotics.

“Medication errors are part of that story.

“When antibiotics are wrongly prescribed or are not taken correctly, it is not just the patient themselves who are at risk, it is all of us.”

In recent years, there has been a UK drive to raise global awareness of the threat posed to modern medicine by antimicrobial resistance.

If antibiotics lose their effectiveness, then key medical procedures – including gut surgery, cesarean sections, joint replacements and chemotherapy – could become too dangerous to perform.

Speaking at the World Patient Safety Summit in London his comments came as the Health and Social Care Secretary, Jeremy Hunt, also drew attention to medication errors.

Research commissioned by Mr Hunt’s Government department highlighted how more than 200 medication errors are made in the NHS every year.

The mistakes, which includes giving patients the wrong medication, could contribute up to  22,000 deaths annually in England, the study revealed.

Mr Hunt said the research shows medication errors are “a far bigger problem than generally recognised” and are causing “totally preventable” harm and deaths.

Dr Ghebreyesus told the summit that the cost of medication-related errors around the world has been estimated at 42 billion dollars annually.

Using his speech to highlight how the reasons for errors “are many”, he said examples include medicines looking or sounding the same, as well as patient identification issues.

But Dr Ghebreyesus said there “are ways to avoid all these errors”.

“Our message is simple – know, check, ask,” he said.

“Patients must know their medication, check that it is the right dose and ask their health provider if they are unsure,” he said.

“Health providers must also know their medication, check that they have the right drug at the right dose, for the right patient at the right time, and ask the patient if they understand.”

He also told the summit that as much as policies and systems are important, in the end, health services are delivered by people.

“Very often harm happens not because of incompetence or neglect, but because those workers are tired and overworked,” he said.

“Those facilities are overcrowded, or because of staff shortages, poor training or the wrong information being given to patients.

“We must therefore give all those workers the conditions, the skills, the training and the tools to do their jobs to the best of their ability.”