Managing Parkinson’s Disease: An Informational Guide
It is a slowly progressing chronic neurologic disease mostly characteristic for people of elderly age. This is a degenerative illness of the extrapyramidal motor system induced by the accelerating destruction of neurons that release dopamine which is one of the most important neurotransmitters, primarily in the substantia nigra, and other areas of the central nervous system (CNS). The insufficient release of the substance induces to the activating impact of basal ganglia on the cortex of the brain. The main signs of the condition onset are: muscle stiffness; hypokinesia (the state of insufficient motor activity of the organism with the restriction of the tempo and volume of movements); tremor; and posture violation.
Unfortunately, to date, the disease is impossible to be cured. It means that the manifestations can be minimized but not completely eliminated if you buy antiparkinsonian drugs.
The existing methods of medicinal and surgical treatment can significantly improve the quality of life of individuals with the disease and slow down the development of it.
The term Parkinsonism is a general notion used for a number of conditions and disease with the above-listed major symptoms. But the most notorious form of the disorder is Parkinson’s disease which is an idiopathic condition, i.e. the autonomous disease not associated with the genetic factors or other diseases.
The name of the condition was suggested by the French neurologist Jean-Martin Charcot as a tribute to the British physician and author of “The essay on the tremulous paralysis”, James Parkinson, whose work was not properly appreciated during his lifetime
What are antiparkinsonian medications?
The medicinal formulations used for Parkinsonism are aimed at elevating the dopamine compound in the CNS as its low levels are the major cause of the symptoms. Dopamine along with acetylcholine, serotonin, and norepinephrine is the most important neurotransmitter. Its main effect is manifested in the striatum on predominantly postsynaptic D1 and D2 receptors. Re-seizure of dopamine in the presynaptic endings and its inactivation proceeds via dopamine transports.
Subsequently, dopamine is destroyed by the action of monoamine oxidase type B and catechol-O-methyltransferase. The lack of dopamine leads to an overabundance of acetylcholine and a lack of serotonin and norepinephrine which results in a violation of coordinated movements or the onset of unintentional, involuntary movements.
The elevation dopamine level is made in several ways: by supplementary feeding to the brain of dopamine or substances acting as dopamine; a blockade of enzymes that promote the breakdown of the neurotransmitter (COMT-, MAO-B-, NMDA-blockers), and a lowering of the elevated levels of acetylcholine (anticholinergics).
Classification of antiparkinsonian medicines
Within the framework of medical management of Parkinson's disease the following medicinal preparations are utilized:
1. Levodopa along with aromatic L-amino acid-decarboxylase (AADC) blockers;
2. Dopamine agonists (substances that promote the release of dopamine);
3. Blockers of enzymes inducing the destruction of dopamine;
4. Drugs that act on the manifestations of the disease are not through dopamine mechanisms: amantadine and anticholinergic medicines.
Levodopa
Levodopa is a direct predecessor of dopamine. After entering the blood from the bowel, it then penetrates the CNS. In the striatal system of the brain, the preparation is perceived by the remaining dopaminergic nerve endings and, with the aid of decarboxylase, is transformed into dopamine. The substance formed this way supplements the dopamine produced by the organism and does not differ in its properties from the endogenous one.
The effective dosages of the preparation necessary lead to the onset of pronounced peripheral actions - nausea and elevated arterial pressure. Therefore, levodopa is utilized exclusively along with a peripheral decarboxylase blocker (benserazide or carbidopa). At our med store, we offer you to buy antiparkinsonian drugs based such as Carbidopa plus Levodopa. The medication has biological availability of around 100 percent. The max level in the blood is reached in 30-60 minutes.
Dopamine agonists
Dopamine agonists render stimulating effect directly on dopamine receptors. They do not turn into active forms of dopamine, like Levodopa. All dopamine agonists exert their effect through the stimulation of D2 and D3 receptors, the drugs differ, however, from each other in their effect on other dopamine receptors, duration of action, and adverse reactions. Dopamine agonists are an important part of Parkinson's therapy. Tests have shown that if the therapy of Parkinsonism begins with the utilization of dopamine agonists or their combination with preparations with Levodopa in their composition, the development of dyskinesia and other motor complications occurs somewhat later. The subject of discussion is also the possible protective effect of dopamine agonists on dopamine-producing nerve cells. On the other hand, due to the simultaneous binding of peripheral dopamine receptors, dopamine agonists may cause more severe side effects than Levodopa, namely: orthostatic circulation disorder and nausea, less often leg edema, dopamine-induced psychoses, impulse control impairments, and fatigue.
10 dopamine agonists (5 ergoline and 5 nonergolinic derivatives) are allowed on the market. Non-agroline preparations are first choice medicines, these are oral preparations for piribedil, pramipexole, and ropinirole, a transdermal patch rotigotine, and parenteral apomorphine. Ergoline derivatives due to their side effects (increased risk of pleuropulmonary, retroperitoneal and cardiac fibrosis) are second choice drugs. These include bromocriptine, cabergoline, alpha-dihydroergocryptine, lisuride, and pergolide.
Blockers of enzymes involved in the destruction of dopamine
Preparations of this group block enzymes that catalyze the metabolism of dopamine, thereby increasing its level. These include inhibitors MAO-B inhibitors.
Catechol-O-methyltransferase inhibitors (COMT)
In this group, two preparations are known on the market: entacapone and tolcapone. It is possible to utilize them along with levodopa. At the end of 2003, a combined preparation containing levodopa, Carbidopa, and entacapone had been introduced onto the market.
Monoamine Oxidase Type B Inhibitors (MAO-B)
The preparations of this group reduce the cerebral oxidant metabolism of dopamine and therefore elevate its level in the striatal (possibly also in the extrestrial) system. There are two drugs on the market with selective inhibition of B-type monoamine oxidase: selegiline is the first-generation medication; and rasagiline, a second-generation medication, the advantage of which is the rapid achievement of maximum plasma concentration within one to two hours after administration and the sufficiency of one intake a day.
Drugs that act on the manifestations of the condition not through dopamine mechanisms
This group includes amantadine and budipin.
Amantadine - its effect is due to incomplete blockade of NMDA receptors, which causes anticholinergic action. It Produced in the form of hydrochloride (for parenteral use) or sulfate (for oral use). It is utilized both in mono- and in combined therapy. Due to the ability to use it parenterally, it is used in the therapy of akinetic crises. But the medication has a serious adverse effect which is the causing of psychosis and confusion, especially in old and multimorbid (suffering from multiple diseases) individuals with dementia - which limits the use of the preparation in this group.
Budipin has a mechanism similar to amantadine. In small uncontrolled studies, his positive effect on tremor was shown. But due to the risk of occurrence of the QT-interval elongation, periodic ECG monitoring is required.
Central choline-blockers
Preparations of this group are the very first in the group of antiparkinsonian. They have been used since 1860, then in the form of tinctures of belladonna. The market was released: biperiden, bornaprin, methixen and triexyphenidyl.
Antiparkinsonian medications you can buy at RXShopMD
- Sinemet, a combination product based on Carbidopa and Levodopa is an antiparkinsonian, dopaminergic medication that inhibits decarboxylase. It is used for the therapy of Parkinson's disease symptoms such as rigidity, tremor, dysphagia, sialorrhea, orthostatic instability of the body.
- Trivastal based on Piribedil by Serdia Pharmaceuticals is an antiparkinsonian preparation, an agonist of dopamine receptors. The preparation renders stimulating effect on the dopamine receptors in the CNS, improves the blood inflow to brain tissues, their supply of oxygen, and cerebral metabolism, promotes the transfer of nerve impulses, raises the electrical activity of cortical neurons. The preparation is utilized for Parkinson’s disease and other degenerative conditions including dementia.
Please note that although we offer you to get to buy antiparkinsonian medications without Rx, it is still highly advised to follow the instructions of your doctor on the selection of the preparation and the therapy itself.