Medications used to treat impulsivity linked to Parkinson’s drugs Mirapex (pramipexole) and Requip (ropinirole) may be ineffective, a preliminary study has found. In fact, selective serotonin reuptake inhibitors and glutamatergic modulators appear to worsen symptoms associated with these drugs, the investigators reported.

People with Parkinson’s disease are at risk of developing impulse control disorder related to Mirapex and Requip. The condition can lead to disruptive behaviors such as compulsive shopping, gambling and hypersexuality. Some drugs are thought to be useful in easing this medication-linked side effect. These include atypical antipsychotics, selective serotonin reuptake inhibitors, and glutamatergic modulators.

To further investigate whether these drugs can indeed ease symptoms, the researchers analyzed health data from more than 900 Parkinson’s patients who took either Mirapex and Requip and also took at least one additional medication to ease symptoms of impulsivity.

None of the medications appeared to reduce the risk of impulse control disorder episodes related to Mirapex or Requip. In addition, selective serotonin reuptake inhibitors and glutamatergic modulators appeared to significantly increase the risk of further incidents, reported Nakyung Jeon of Chonnam National University, South Korea, and Marco Bortolato of the University of Utah.

The researchers caution that the results are observational and not conclusive. The study was published in Plos One.