When other factors are involved, such as the side effects of some anti-Parkinson medicines or other drugs, depression and other psychosocial factors which may be unique to a patient suffering with a disease like Parkinson’s disease, substance abuse can become a real possibility.

The question as to whether Parkinson’s disease is related to substance abuse is discussed below. Parkinson’s patients who are abusing any substance, whether a pharmaceutical drug or other illicit substance, should realize that the misuse and their addiction could negatively impact upon their condition. Apart from drugs interactions with Parkinson’s disease medicines, may drugs can contribute to or exacerbate the signs and symptoms of Parkinson’s disease or possibly even accelerate the progression of Parkinson’s disease.

For information on other forms of addiction – gambling, sex and so on, please refer to the article on Compulsive Behavior in Parkinson’s Disease.

Cigarette Smoking

There seems to be an inverse proportion to the number of cigarettes smoked and the development of Parkinson’s disease. It has been seen that patients with Parkinson’s disease are less likely to have ever smoked. Current smokers, in relation to ex-smokers, show this inverse relation better. The neuroprotective effect of cigarette smoke may be the reason for this, but should not prompt one to start smoking.

Caffeine Intake

Research also shows a decreased incidence of Parkinson’s disease in people consuming large amounts of caffeine, indicating that caffeine may have a neuroprotective effect too. Consuming 2 cups or more of tea per day, or 2 or more cola drinks per day may play a role in reducing the risk of Parkinson’s disease.

Alcohol Consumption

While it has been suggested that alcohol consumption may protect against Parkinson’s disease, there is no clear evidence to support this theory. Moderate beer consumption may lower the risk of developing Parkinson’s disease, but wine or liquor do not seem to offer any protection.

Drug Addiction

Research has shown a relationship between Parkinson’s disease and drug addiction. Parkinson’s disease patients sometimes become addicted to the drugs they are taking or develop various addictions as a result of their medication.

Parkinson’s disease patients lack dopamine, a neurotransmitter in the brain (a chemical messenger) which is responsible for motor movements as well as the ability to experience pleasure and pain. Dopamine is also involved with the reward pathway of the brain. Patients with drug addictions, on the other hand, have an excess of dopamine in their brain. This can explain how Parkinson’s disease patients, when treated with dopamine agonists (which increase the dopamine levels in the brain) start to show personality traits such as addiction which are normally alien to the patient. Treatment with levodopa does not usually produce such side effects.

Narcotics

Narcotics such as morphine are sometimes given to Parkinson’s disease patients to alleviate pain not responding to any other treatment. Narcotics are often prescribed in combination with other drugs such as nonsteroidal anti-inflammatory drugs (NSAIDs). Although not usually dangerous in prescribed doses, the potential danger of addiction remains in such patients.
MPPP (1-methyl-4-phenyl-4-propionpiperidine), is an analogue of meperidine (a synthetic opioid), a street drug. During its illicit manufacture, MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) was inadvertently synthesized, whose use rapidly produced symptoms of Parkinson’s disease in the users, with toxicity leading even to death.

Methamphetamine

Methamphetamine is closely related to amphetamine but its effects on the central nervous system seem to be greater than those of amphetamine. Methamphetamine causes release of dopamine in the brain and there may be long-term impairment in dopamine function following abuse of this drug.

Cocaine

Studies show that cocaine-users may be more at risk of developing Parkinson’s disease. Pregnant women abusing cocaine could be at increased risk of giving birth to children who will develop Parkinson’s disease later in life.

Related Article

1. Compulsive Behavior in Parkinson’s Disease

References

1. Alcohol Consumption and the Incidence of Parkinson’s Disease
2. Parkinson’s Disease Risks Associated with Cigarette Smoking, Alcohol Consumption and Caffeine Intake

]]> http://pdring.com/substance-abuse-and-addiction-in-parkinson%e2%80%99s-disease.htm/feed 0 http://pdring.com/drug-therapy-in-parkinson%e2%80%99s-disease.htm http://pdring.com/drug-therapy-in-parkinson%e2%80%99s-disease.htm#comments Sun, 26 Jul 2009 11:06:55 +0000 Dr. P.D. http://pdring.com/?p=101 Parkinson’s disease is a degenerative disease of the brain where there is decreased production of the chemical transmitter known as dopamine. The classical symptoms of Parkinson’s disease are tremor, rigidity, bradykinesia (slowing of movement) and loss of postural reflexes. Drugs are the mainstay of treatment in Parkinson’s disease and while there is no definite cure, drug therapy is used to help control the symptoms.

Types of Parkinson’s Drugs

Levodopa

Various drugs have been used for the treatment of Parkinson’s disease but the most effective treatment so far is a combination of levodopa and a peripheral acting dopa-decarboxylase inhibitor. Levodopa is a natural substance in our body which is converted to dopamine in the brain. However, if taken orally, about 90% of it is converted to dopamine outside the brain and only a small proportion of it reaches the brain. This causes side effects like nausea and vomiting, which can be offset by combining levodopa with peripheral decarboxylase inhibitors like carbidopa. Levodopa is especially effective in improving bradykinesia and rigidity of Parkinson’s disease, and tremor to a lesser extent, but initial treatment with levodopa should be delayed because of the long term side effects such as involuntary movements, depression, hallucinations and delusions. With long term use, the effect of levodopa shows some fluctuation in response, known as the ‘on-off phenomenon’ where there is unpredictable action of the drug. This can be treated by variations in dose.

Dopamine Receptor Agonists

These drugs are not as effective as levodopa in the treatment of Parkinson’s disease but their action lasts longer and they help considerably during the on-off effect of levodopa. Side effects such as dose fluctuations or dyskinesia (involuntary movements) are rare, although once dyskinesia develops, dopamine agonists tend to make them worse. Other side effects are nausea, vomiting, confusion and hallucinations. Pramipexole and ropinirole are administered as oral preparations while rotigotine can be used in patch form. Pergolide and bromocriptine are not used because of causing problems in heart valves. Apomorphine injection maybe used to give rapid short term relief.

Monoamine Oxidase B (MAO-B) Inhibitors

Drugs like selegiline and rasagiline are mildly effective. There may be drug reaction with other medications, especially narcotics and antidepressants.

Catechol-Omethyl Transferase (COMT) Inhibitors

COMT inhibitors like entacapone can be used with levodopa by helping to reduce its dose and thus reduce the instance of motor fluctuations caused by levodopa.

Anticholinergics

Anticholinergics like benzhexol are effective in controlling tremor and rigidity but not bradykinesia, hence they may be used in the early stage of the disease. The side effects are confusion and hallucinations, especially in the older age group, in whom these drugs are best avoided. The other side effects are blurred vision, dryness of mouth, constipation and retention of urine.

Amantadine

Amantadine can be used in early stage of Parkinson’s disease before starting with stronger drugs, and in the later stage along with carbidopa-levodopa preparations to offset side effects such as involuntary movements. The side effects of this drug are confusion, seizures, ankle edema.

These drugs are currently used in Parkinson’s disease but ongoing drug research to isolate compounds to reduce the severity of Parkinson’s symptoms offers hope for more effective drugs in the future.

Listed below are some of the more frequently asked questions by people with Parkinson’s disease with the aim of helping you get a better understanding of the disease and what’s to be expected with the progression of the disease.

• Is Parkinson’s disease hereditary?

Parkinson’s disease is not generally thought to be a hereditary disease in that it doesn’t get passed from one generation to another, however the risk of getting the disease if someone in your family has it is slightly increased. Genetic factors are linked this way just as heart disease and diabetes are, though the exact reason why genetic factors are increased remains unclear.

• Do only old people get Parkinson’s disease?

While Parkinson’s disease is more prevalent in people aged over 60, 1 in 20 sufferers are under the age of 40 and 1 in 10 are under the age of 50. In only very rare instances does Parkinson’s disease affect anyone under the age of 25.

• Can toxic substances cause Parkinson’s disease?

Some people who use drugs have become ill with symptoms similar to those which Parkinson’s disease sufferers get, however most of these were found to be brought on by poisonous by products contained in the drugs taken. By products very similar to pesticides were found to be used in drugs, however no substance has been positively identified as having been the cause of Parkinson’s disease.

• Is there a cure for Parkinson’s disease?

At the present time there is no cure for Parkinson’s disease though there are now many treatments available for alleviating symptoms associated with the disease. Parkinson’s is a disease which does progress even with medication, medication will normally give the sufferer a rest period of around two years, however problems associated with the disease will begin to occur again.

• Why does medication for Parkinson’s produce an on/off effect?

The rest period that is associated with Levodopa treatment and which will normally occur in about two years of using the medication causes what patients describe as on/off effects, a person will have adequate control of their illness for a period of time then suddenly switch to periods of immobility.

While the exact reason for this effect is not know it is thought that as the disease progresses the number of dopaminergic cells decrease so there are fewer cells in the brain to take the drug. Also because Levodopa is taken orally there are fluctuations in the plasma concentrations of the drug.