LOS ANGELES, April 13 (Xinhua) -- Parkinson patients taking a class of Parkinson's disease drugs might develop destructive behaviors such as compulsive gambling or hypersexuality, a new study has found.

    One in six patients developed unhealthy behaviors after taking therapeutic doses of dopamine agonists, such as pramipexole and ropinirole, according to the study conducted by researchers at the Mayo Clinic in Rochester, Minnesota.

    But lower doses of dopamine agonists appear to curb compulsive acting out, said the study appearing in the April issue of Mayo Clinic Proceedings.

    "It is crucial for clinicians prescribing dopamine agonists to apprise patients as well as their spouses or partners about this potential side effect. The onset can be insidious and overlooked until life-altering problems develop," J. Eric Ahlskog, a Mayo Clinic neurologist, said.

    "It also is worth noting that the affected patients were all taking therapeutic doses. Very low doses, such as those used to treat restless legs syndrome, carry much less risk."

    "For some patients, a reduction in the dose of the dopamine agonist may prove to be sufficient treatment, although total elimination of the offending drug is often necessary," Ahlskog added.

    The researchers based their study on the medical records of 267Parkinson's disease patients treated at the Mayo Clinic between 2004 and 2006. Of those patients, 66 were taking dopamine agonists, including 38 who were taking therapeutic doses (doses expected to be at least minimally beneficial).

    Seven of the 38 patients taking therapeutic doses of dopamine agonists developed compulsive gambling or hypersexuality after they started taking the drugs, the study found.

    None of the other Parkinson's patients developed those destructive behaviors, including the 28 patients taking subtherapeutic doses of dopamine agonists, or the 178 patients taking carbidopa/levodopa, the standard drug for Parkinson's disease.