The prescription drug pregabalin has been linked to a number of deaths in the UK and around the world.

Many users buy the drug illegally on the black market, often from unregulated websites.

It comes as tablets, capsules or in liquid form, and may be called Alzain, Axalid or Lyrica, depending on the brand.

Prescription rates are showing signs of levelling off across the UK, but doctors say it can be a very useful treatment for patients when taken correctly, and should remain available.

Some call pregabalin the new Valium or “Bud” (as in Budweiser beer) because it can make users feel relaxed, in a similar way to tranquilisers or alcohol.

Taking too much of it – particularly when combined with other street drugs that also have a sedative effect – can cause drowsiness and breathing problems.

Patients who are prescribed pregabalin are advised to avoid alcohol.

In many cases, the drugs had not been prescribed.

Taken together, opiates and pregabalin slow down breathing. An emergency antidote called naloxone that works against opiates does nothing to counteract pregabalin’s effects.

There have also been a significant number of deaths in Northern Ireland.

That compares to one death in 2013, nine in 2016, rising to 77 in 2019 before falling back.

Pregabalin’s calming effect – sometimes described as a “gentle high” – can mean some users underestimate the drug’s addictive nature over time.

Dependence on pregabalin is especially dangerous for those with a prior history of drug abuse or addiction.

Some people find it hard to stop taking pregabalin.

Withdrawal symptoms can include mood changes such as anger and irritability, anxiety and panic as well as physical symptoms like sweating, nausea and chills.

Anyone trying to come off the drug should seek health advice first.

You should not suddenly stop taking pregabalin unless advised by your doctor. The dose is usually reduced over a week or longer.

The Misuse of Drugs Act 1971 divides drugs into three categories, class A, B and C, according to the harm they cause when misused.

Pregabalin was made a class C drug in 2019. That means it is illegal to possess pregabalin without a valid prescription, or to supply it to others.

Police Service of Northern Ireland (PSNI) statistics show pregabalin is the fourth most commonly seized drug behind cannabis, cocaine and benzodiazepines.

Between July 2021 and June 2022, pregabalin was seized by officers on 804 occasions.

In the following twelve months, that figure rose to 1,081 – an increase of more than 34%.

Since being introduced in the US and UK in 1993, pregabalin has spread across the world.

A study published by the medical journal Nature Communications estimates that the number of doses of pregabalin and gabapentin taken daily around the world rose more than fourfold between 2008 and 2018.

There has also been a global increase in pregabalin abuse and deaths.

Large quantities of illegally-traded pregabalin have been captured in the UAE and Kuwait.

If you have been affected by addiction, help and support is available at BBC Action Line.

If you live in Northern Ireland, you can also call the 24-hour helpline Lifeline, on 0808 808 8000.