Cure for Parkinsons isn't made because it is an overwhelmingly powerful aphrodisiac?

So I’m talking with a drug company exec about FDA policies concerning safety versus efficacy and he drops this little bomb on me, that there is a cure for Parkinsons but it isn’t manufactured because it is such a powerful aphrodisiac. According to him, it would be the ultimate date rape drug and is therefore suppressed. Anyone who took it would be so overcum that they would copulate with anything at hand.

Color me skeptical. I had just met this gentleman and I suspect he was pulling my leg. What’s the SD?

Parkinson’s is a loss of dopamine producing cells in the brain.

Taking regular doses of L-dopa (synthetic dopamine) is merely a treatment…a stop-gap measure.

Nothing short of stem cell/fetal cell transplants to replace the damaged brain tissue would be a cure.

We do some work on Parkinson Disease in the lab and I am familiar with modern treatment and some in development. PD is interesting simply because there is a lot of treatment for it – most neurologic disorders don’t have anywhere near it.

PD is a selective loss of dopaminergic neurons in a part of the midbrain called the substantia nigra. To “cure” it, one would need to replace these neurons. To halt the disease progression, one would need to prevent these from dying. There is no current medical technology to either of these. The best we can do is to supplement dopamine to the places that these neurons project. We have many ways of doing this, from direct supply of dopamine to inducing more dopamine release to surgical cutting of inhibitory neurons. This can alleviate symptoms and slow progression of the disease. There are two problems associated with this. First is that if you put too much dopamine in at the wrong place, you can get hallucinations, psychotic episodes, uncontrolled movements, and a bevy of other side effects. The second is that the brain often adapts to putting dopamine back in, and downregulates the dopamine receptors. So therapy only slows the progression – the brain adapts to the exogenously supplied dopamine and the drugs become less effective over time.

Elsewhere in the brain, dopamine can be a “feel good” neurotransmitter (although this is a bit of oversimplification). Dopamine has been associated with addiction, pain tolerance, happiness, the whole lot. New antidepressants modulate both the dopamine and serotonin pathways. Also, I have found some references to dopamine inducing hypothalamic oxytocin release in sexual arousal. PD patients often get hyposexual. It is certainly possible that new PD drugs have hypersexuality as a side effect. I have never heard of it, nor can I find any literature references. But, standard therapy can cause hypersexuality or changes in sexual behavior:

Drugs which show efficacy but have terrible side effects are quarantined in FDA trials all the time. “Cure” is probably an exaggeration; although it could be an extremely promising treatment, bad side effects could damn it. This is not unusual.