Recently, I was having some troubles falling asleep because my legs kept messing with me. My ole lady has restless leg syndrome, and she offers me some medicine that was prescribed to her for it – Requip (Ropinirole). To make sure it wasn’t a narcotic, I looked it up.

Well, some things popped out at me… I noticed some similarities in the pharmacology to Caber. Now, I’m not in the medical field, and I don’t know a whole lot about this. I am curious to know – for any of you that are in the medical field or may understand this better than I – if you would mind clarifying?

(I WASN'T SURE WHICH TOPIC TO PUT THIS UNDER. CABER AND PCT CAME TO MIND...)

I am not a 19-nor guy at all.. so, I do not ask this for me. I see all the time that people struggle with finding legit caber. So, my thought process is, if what I’m reading is what I think it is, this drug would act as a substitute for Caber or Prami. Here are the facts:

Caber

Although cabergoline is commonly described principally as a dopamine D2 receptor agonist, it also possesses significant affinity for the D3, D4, 5-HT1A, 5-HT2A, 5-HT2B, 5-HT2C, α2B- receptors, and moderate/low affinity for the D1 and 5-HT7 receptors. Cabergoline functions as an agonist at all receptors except for 5-HT7 and α2B-, where it acts as an antagonist.[3]
Half-life: 63-69 hours (estimated)

Requip

Ropinirole acts as a D2, D3, and D4 dopamine receptor agonist with highest affinity for D2. It is weakly active at the 5-HT2, and α2 receptors and is said to have virtually no affinity for the 5-HT1, benzodiazepine, GABA, muscarinic, α1, and β-adrenoreceptors.[6]
Half-life: 5-6 hrs

I tried to doing a little research to see if any studies had been done on the effectiveness of Requip for Hyperprolactinemia. Turns out there are a lot of studies that pop up on google scholar, BUT 99% of them are not only too vague in the abstract but also required money out of my empty wallet to read the articles. A few of the abstracts did mention that all dopamine agonists have been shown to be effective in the treatment of Hyperprolactinemia. They all seemed to be hitting on the drugs with affinity at the D1 and D2 receptors as being the determining factor. (you’ll notice above that both drugs possess this characteristic) Here is an excerpt from one abstract that I was able to find a tidbit in:

1. Ropinirole, SK&F 101468 has been characterized preclinically as a specific dopamine D2-receptor agonist. Nine male healthy subjects were investigated for the effects on supine and erect heart rate and blood pressure, catecholamines and prolactin, of a single dose of 800 micrograms ropinirole preceded by a single dose of 20 mg domperidone or domperidone-placebo, and those of a single dose of domperidone followed by ropinirole-placebo. 2. Single doses of 800 micrograms ropinirole did not cause clinically significant changes in supine resting heart rate and blood pressure. However, they caused postural faintness on 3 min immobile upright standing on 10/26 occasions. 3. Pretreatment with 20 mg domperidone 1 h before administration of ropinirole prevented the postural symptoms in all but one subject. It did not alter ropinirole's plasma pharmacokinetics. 4. Ropinirole did not alter supine or standing catecholamine concentrations. 5. Domperidone increased the plasma concentrations of prolactin whereas ropinirole administered alone reduced them. A single dose of 800 micrograms ropinirole did not attenuate the prolactin increase induced by a single dose of 20 mg domperidone administered 1 h earlier.

With Caber being so difficult to obtain, I am only wondering would this even be a feasible alternative. It appears to me that it will suffice for prolactin suppression; however, it would require administration much more frequently than say Caber would. Requip is commonly prescribed for restless leg syndrome. The typical quantity would be 30 tabs, and the starting dose for RLS seems to be 0.5mg. Doses do range from 0.25mg to 5mg. According to the study above, 0.8mg showed a decrease in plasma concentrations of prolactin.

I am writing this in hopes to brainstorm the topic. A lot of time and effort has gone into understanding the role of Caber in lowering elevated prolactin due to 19-nor compounds. Using a drug such as Requip would obviously require some trial and error plus lab tests to confirm effectiveness individually. But the scenario comes to mind that either someone has bunk caber or no caber and is experiencing sides. I would imagine that a drug like Requip could easily be obtained from a local doctor to help bridge the gap until good Caber can be obtained; therefore, pulling them out of the pickle.

Thoughts? Any are welcomed…

References:

http://en.wikipedia.org/wiki/Requip
http://en.wikipedia.org/wiki/Cabergoline
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2125.1991.tb03935.x/ab...
http://www.accessmedicine.com/content.aspx?aID=16662534