Warnings about common medications that can cause impulsive behaviours, such as sex and gambling addictions, are being officially reviewed after BBC News identified an error in drug leaflets.
Side effects of a family of drugs used to treat Parkinson’s, Restless Legs Syndrome (RLS) and other conditions have led to huge debts, broken marriages, criminality and suicide, our year-long investigation found. More than 350 affected people have contacted the BBC during that period.
One in six Parkinson’s patients taking the drugs are affected by impulse control disorders, the clinical term for these behaviours, according to one study cited as the largest of its kind.
Yet we discovered those side effects are described as “uncommon” in leaflets for one of the drugs, suggesting they only affect fewer than one in a hundred patients.
After being alerted by the BBC, the UK’s drug safety regulator said that “an error has been identified” and it would be changing that label to “common”.
In response to our findings, the Medicines and Healthcare products Regulatory Agency (MHRA) has also begun reviewing warnings for all eight of these medications, which are known as dopamine agonist drugs.
Boehringer Ingelheim, the developer of Pramipexole – the Parkinson’s drug with impulsive behaviours listed as “uncommon” – said the regulator had approved its leaflets and that it was committed to improving patient safety.
Neither it nor the MHRA were able to say how long the error had existed for, but the BBC has discovered its inclusion in a leaflet from 2021 – meaning patients have been misled for at least five years.
The MP who heads the Health Select Committee has told us she “wants answers” from the MHRA and believes it should apologise to families for the mistake.
“I just can’t even begin to imagine hearing what they’ve been through – abuse, financial ruin, all that you’ve uncovered – and then to find out that they could have been so much better forewarned,” said Layla Moran.
Jane Ryde’s husband became addicted to pornography and demanded sex at least three times a day after being prescribed Pramipexole to treat his Parkinson’s.
She wasn’t warned about these side effects by doctors, but when she read about them in the leaflet, she says she was reassured to see them listed as being “uncommon”.