Warn patients treated for Parkinson's disease about gambling behaviour risk
Patients with Parkinson’s disease should be warned that treatment could be associated with an increased risk of gambling, suggest American researchers (Neurology 2003;61:422).
After a review of 1,884 patients with Parkinson’s disease who were
seen at the Muhammad Ali Parkinson Research
Centre, Barrow Neurological Institute, Phoenix, Arizona, over a 12-month
period, Dr Mark Stacy and colleagues found that seven men and two women
showed signs of pathological gambling.
Of these nine patients, eight were being treated with pramipexole (Mirapexin,
mean dose 4.3mg/day, range 2 to 8mg/day) and one was being treated with
pergolide (Celance, 4.5mg/day) when they started gambling.
The researchers report that the overall incidence of gambling among the
patients was 0.05 per cent. The incidence of this behaviour among pramipexole-treated
patients was 1.5 per cent and 0.3 per cent for pergolide-treated patients.
The researchers point out that the rate of pathological gambling found
in subjects taking pramipexole is only slightly higher than the reported
rate in the general population (0.3 to 1.3 per cent) and other factors
could have contributed to the development of this behaviour.
“However, this clinical observation suggests that higher dosages
of dopamine agonists may be a catalyst to bringing out this destructive
behaviour,” said
Dr Stacy.
He added that it might be appropriate to inform patients of this potential
risk, “particularly patients taking relatively high dosages of
a dopamine agonist, and with a documented history of depression or anxiety
disorder”.
The patients identified as pathological gamblers had been taking pramipexole
or pergolide for between six and 64 months. Seven patients started gambling
within one month of an increase in their dopamine agonist dose.
For six of the patients the gambling was controlled by switching treatment
to ropinirole (Requip). Another patient, who did not tolerate a change
in dopamine agonist therapy, improved after the pramipexole dose was
reduced from 8mg/day to 3mg/day with a concurrent increase in the levodopa
dose.
Pfizer, manufacturer of Mirapexin, said that long-term, controlled clinical
trials of pramipexole involving nearly 1,000 patients with Parkinson’s
disease did not suggest an association between the product and excessive
gambling or other impulsive behaviours. |
