Friday, July 16, 2010

Dopamine Agonists in Psychiatry

The dopamine agonists pramipexole and ropinirole are drugs used in the treatment of Parkinson Disease.

These drugs are now well-established in treating restless legs syndrome (RLS) and periodic limb movement disorder of sleep (PLMS), which are frequent problems afflicting about 10% of the population, and which can negatively impact quality of life & mood symptoms.

There is a small body of evidence showing possible benefits of dopamine agonists in the treatment of depression.

Unfortunately, dopamine agonists can exacerbate addictive/compulsive behaviour: 

Here are some references about the role of dopamine agonists in RLS and PLMS:

Here's a good review article on the use of ropinirole to treat these conditions:
Here's a recent review of dopamine agonists in general to treat RLS:
Here's a 2008 meta-analysis comparing ropinirole with pramipexole for treating RLS.  Pramipexole is shown to be slightly superior:

In this 2010 study, gabapentin was compared to ropinirole for treating RLS.  While ropinirole was superior in reducing objective measures of periodic limb movements, subjects taking gabapentin had a higher subjective benefit:

Here's a case study showing remission of depressive symptoms with ropinirole used as an augmenting agent: 

Here's a 2005 study looking at ropinirole augmentation in treating depression:
This 2010 review in Lancet showed a direct antidepressant effect of pramipexole in Parkinson Disease patients:
Here's a rather weak but positive 2010 paper describing a group of patients with bipolar depression who appeared to benefit from longer-term pramipexole treatment; doses averaged about 1 mg/d:

The side effects from these drugs include frequent nausea and dizziness, possibly some daytime sleepiness.  Psychiatric adverse effects can include hallucinations, and increased compulsive or impulse-control problems.

In summary, I think dopamine agonists have a role in selected psychiatric conditions, particularly if there are restless-legs symptoms contributing to insomnia or nocturnal discomfort.  They may help treat refractory depression, but there is a risk of causing impulse control problems or hallucinations in predisposed individuals. 

1 comment:

Anonymous said...

I have a prolactinoma as well as bipolar disorder type 2. My current medications are Seroquel (200 mg IR), Zoloft (75 mg) and dopamine D2 agonist Dostinex (0.25 mg). What I have noticed after years of trying different medications is that WITHOUT a dopamine agonist I become psychotic (whereas too MUCH dopamine makes me psychotic as well obviously, but when I found the right dose for me it started helping wonderfully). Also, it gets me off the sofa. I don't feel Dostinex does much else for my depression, but together with Zoloft and Seroquel it has made me feel more normal than I have felt in my entire adult life.