Nicotine Effect on Dopamine Release

Nicotine, whether on its own or with other monoamine oxidase inhibitors and yet undiscovered chemicals in cigarette smoke, stimulates the dopaminergic neurons in the brain. These dopamine-producing nerve cells are progressively destroyed in Parkinson’s disease and dopamine is supplemented with the aid of medication like L-dopa. However, the drawback with L-dopa is the side effects and attempting to reduce the dose only worsens the symptoms.

Although previous studies did indicate that the damage to the substantia nigra, the area of the brain most affected in Parkinson’s disease, was limited with nicotine and exacerbated by pesticides and toxins, the exact mechanism and receptor sites for this neuroprotective effect of nicotine were not conclusively verified. It was believed to be those same receptors, alpha-7 nicotine receptors, as was verified by the recent study. These previous studies also put forward the idea that other non-receptor mediated mechanisms may offer protection by suppressing the effect of toxins and altering the activity of the enzyme monoamine oxidase.

Nicotine Receptors on Dopamine Nerves

In the recent study conducted in France, it was found that nicotine spares the gradual loss of these neurons by acting on alpha-7 nicotine receptors. Mice that were genetically engineered without these receptors were shown to be more likely to lose dopaminergic neurons than normal mice with these receptors. These findings were recently published in the FASEB journal (August 2011) and go a long way in opening up possibilities of new drugs that target the alpha-7 nicotine receptors. New generation drugs may be able to prevent Parkinson’s disease in high risk individuals or slow the progression of the disease.

Smoking Benefit in Parkinson’s Disease

The findings of the recent study are promising and offers new hope for Parkinson’s disease like the recent VPS35 genetic mutation discovery which sheds new light on familial Parkinson’s disease. However, this should not encourage every PD patient to take up cigarette smoking. The host of carcinogens (cancer-causing chemicals) in cigarette smoke may be a greater risk to one’s health and lifespan, along with the known cardiovascular implications of cigarette smoking. Nevertheless, the finding does open up some exciting avenues for future development of drugs that can take advantage of the neuroprotective effect of nicotine by now identifying the specific receptors responsible for this benefit.

An Overview of Stem Cell Therapy for Parkinson’s Disease

Stem cells are immature cells which differentiate into different cells in the body. It is most abundant in fetal life but small amounts of partially differentiated stem cells are available in various tissues even in adulthood. Some tissues have large amounts of stem cells, like the bone marrow with its hematopoietic stems cells, but these cells are partially differentiated already and therefore only capable of forming the necessary blood cells.

A recent procedure has been able to ‘wipe’ clean these partially differentiated stems cells to once again form ‘blank’ stem cells that can then be stimulated to differentiate into a cell types of choice. These cells are known as induced pluripotent stem cells (iPSC’s) and made waves in the medical science community in 2010. It holds much promise for a number of conditions, not only Parkinson’s disease.

Parkinson’s disease arises due to a progressive decrease in the number of dopamine-producing neurons (dopaminergic neurons) in the substantia nigra of the brain. The lower than normal levels of dopamine, a neurotransmitter, is responsible for the features of Parkinson’s disease. In a nutshell, stem cell therapy holds the hope that by differentiating ‘blank cells’ into dopamine-producing neurons, at least partially, and injecting it into the substantia nigra, more dopamine-producing neurons will be available. Read more on Would Stem Cell Therapy Be A Parkinson’s Cure?

Stem Cell Clinics for Parkinson’s Disease

One of the challenges with regards to induced pluripotent stem cells is controlling the ‘reprogramming’ of the cell to form the dopaminergic neurons and integrating it into the brain tissue. In experiments on lab rats it was seen that integrating these dopaminergic neurons could be achieved on the rat. The net result could be an improvement in the clinical symptoms of Parkinson’s disease. However, the efficacy on human subjects has to be ascertained by properly structured and controlled clinical trials.

Stem cell therapy is available at a number of clinics but the long term effects and potential complications have yet to be ascertained. Although many of clinics market these techniques quite aggressively, particularly on the internet, none can truly lay claim to ‘curing’ Parkinson’s disease. There are also the concerns that undifferentiated stem cells contained in the ‘mix’ may also be delivered into the brain tissue. These cells may have the potential to differentiate abnormally and grow rapidly and become tumors. The other factor to consider is that the exact pathogenic mechanism of Parkinson’s disease is still not clearly known. Therefore the very mechanism that can affect the naturally-occurring dopaminergic neurons may also affect the iPS dopaminergic neurons. Considering the cost factor of stem cell therapy, this can be an expensive procedure that may only offer short term results, if any.

This is not to say that the therapy offered by these clinics are not beneficial to some patients to some degree but it should not offer false hope. Most dedicated Parkinson disease organizations are critical of these clinics and the therapy on offer not because of the therapy itself, but rather in the manner that it is marketed and the sometimes blatant but often subtle promise of a cure.

What are Pluripotent Stem Cells?

Stem cells are those unspecialized cells that have the potential to develop into different types of cells in our body during early life. There are also some partially differentiated stem cells in different tissues in adults which can replenish worn out cells. The most significant quantity of these cells lie within the hemopoietic tissue where new blood cells are constantly produced. In other tissues, cell replacement is via cell division although small amounts of stem cells will allow for replacement of tissue.

Types of Stem Cells

Embryonic stem cells – all cell types of the body are derived from these cells. These stem cells are also capable of dividing and replicating over a long period of time without differentiating into other cell types. Human embryonic stem cells are derived from human embryos and grown in the laboratory. Present research is aiming at stimulating these stem cells to undergo differentiation into specific cell types which can be used in the treatment of various diseases, including Parkinson’s disease, by transplanting these differentiated cells into specific diseased regions of the body.

Non-embryonic stem cells (adult or somatic stem cells) – these are undifferentiated or partially differentiated cells present amongst differentiated cells in a tissue or organ. These stem cells undergo differentiation into cells similar to the neighboring ones only and are mainly involved with tissue repair.

Induced pluripotent stem cells (iPSCs) – specialized adult cells may be reprogrammed genetically (through introduction of embryonic genes) to behave like embryonic stem cells. These are known as induced pluripotent stem cells, which have the potential of differentiating into and generating specific cells and tissues.

Induced Pluripotent Stem Cell Therapy in Parkinson’s Disease

An insufficient number of of dopamine-producing neurons (nerve cells) due to cell degeneration causes the symptoms of Parkinson’s disease. Replacing these cells with other dopaminergic neurons is the basis of iPSC therapy in PD.  Differentiation of the iPSCs into specific cells and generation of new cells may cause improvement in PD.

IPSCs produce a renewable source of replacement cells which may be effective in treating various disorders, including PD. By using the patient’s own adult stem cells to produce these iPSCs, chances of rejection by the immune system are greatly reduced. Cells generated from human iPSCs may be used to test the efficacy and safety of new drugs. Development of the disease process may be studied and better understood, thus helping in finding new ways of controlling and preventing the disease.

Challenges of iPSC Therapy

Scientists face the challenge of controlling the development of iPSCs into different cells in the body. Ethical issues also need to  be addressed although iPSC therapy is less contentious since embryonic stem cells from discarded fertilized embryos are not used.

Before iPSCs can be used successfully in therapy for Parkinson’s disease or any other disorder, certain points have to be kept in mind, which are very essential if transplantation and grafting are to be effective during treatment. The iPSCs should :

• Survive in the recipient after transplant.
• Integrate into the surrounding tissue after transplant.
• Function properly for the duration of the patient’s life.
• Cause no harm to the recipient.
• Viruses used to introduce the reprogramming factors into adult cells in animals may have other health consequences and the safety in humans needs to be considered.

Related Articles

1. Would Stem Cell Therapy Be a Parkinson’s Cure?

]]> http://pdring.com/induced-pluripotent-stem-cell-therapy-in-parkinsons-disease.htm/feed 2 http://pdring.com/gene-therapy-in-parkinsons-disease.htm http://pdring.com/gene-therapy-in-parkinsons-disease.htm#comments Sun, 31 Oct 2010 23:07:57 +0000 Dr. Chris http://pdring.com/?p=286 Significant research and several clinical trials have been done regarding the efficacy of gene therapy in Parkinson’s disease (PD). While many claims have been made involving numerous wonder cures for PD, gene therapy may hold the exciting possibility of not only delaying disease progression but also halting it completely.

Parkinson’s disease is progressive a neurodegenerative disorder where there is steady loss of brain cells of the substantia nigra involved in the production of the chemical neurotransmitter dopamine. Refer to Parkinson’s Disease Brain Chemistry for more information.

Medication with levodopa and other related drugs are the mainstay of treatment which can only offer temporary relief but no lasting cure. Research focused on developing other methods, such as gene therapy, which can help to treat or modify the disease process more effectively is continuously being done.

What is gene therapy?

Simply, gene therapy involves the introduction of healthy genes into a person with defective genes which may be the cause of a certain medical problems, such as Parkinson’s disease. The healthy genes are expected to work on the target cells and cause changes in them that will trigger them to resume producing dopamine and thus reduce symptoms or altogether halt the progress of PD. For this new therapy to be acceptable, the benefits should be long-term and without other complications or side effects.

Virus Carriers for Gene Therapy

During gene therapy, genetic material is transferred to the recipient using a vector virus which is considered not to be harmful to humans. Either recombinant adeno-associated virus type 2 (rAAV2) or lentivirus vectors have been used
in clinical trials in an attempt to trigger :

• Increased dopamine levels via increased neurotransmitter production.
• Modulation of the neuronal phenotype.
• Neuroprotection.

Increased dopamine production may be achieved by means of the first two methods, by direct delivery of genes involved in neurotransmitter production (amino acid decarboxylase, tyroxine hydroxylate and GTP (guanosine triphosphate) cyclohydrolase 1).

To bypass the degenerating nigrostriatal pathway, rAAV2 is used to transfer glutamic acid decarboxylase (GAD) to the subthalamic nucleus (STN). GAD acts as a catalyst in the production of a neurotransmitter called GABA, which acts as a direct inhibitor on the overactive cells in the STN.

Protection of the degenerating nigrostriatum (neuroprotection) is hoped to be achieved by striatal delivery of rAAV2 containing the neuroprotective gene neurturin.

Stem Cells and Gene Therapy for Parkinson’s Disease

Research continues so as to find newer and more effective means of delivering genes and sustaining their effects. Using stem cells as a means of introducing genes is being studied. It is claimed that hematopoietic stem cells from blood and bone marrow can be genetically transformed outside the body and then re-introduced into the patient so as to eliminate the necessity of repeated introduction of gene into the patient but results have not been too promising. Embryonic stem cells (because of their versatility) may be a better alternative to hematopoietic stem cells but ethical issues may have to be looked into.

Although studies done so far seem promising regarding gene therapy as a means of treating PD, longer follow-up still needs to be done to determine if improvements can be sustained over a prolonged period. It is to be hoped that gene therapy will be more effective and less invasive than the current medical or surgical treatments available, with less side effects.

Risks of Surgery

Any surgery carries certain risk with it. This includes :

• Anesthetic complications such as reaction to anesthesia drugs, though rare, may be life-threatening.
• Problems may arise while intubating a patient (inserting the breathing tube).
• Aspiration of food or liquids into the lungs.
• Increased heart rate, blood pressure, or rapid increase in body temperature (malignant hyperthermia).
• Hemorrhage or excessive bleeding during surgery or in the post-operative period.
• Accidental injury to other organs during surgery.
• Deep vein thrombosis (DVT) is a serious risk of surgery which may occur due to prolonged immobilization after surgery. Blood clots may travel to the lungs and cause pulmonary embolism or to the brain, causing a stroke.
• Pneumonia.
• Urinary tract infection.
• Breathing problems after surgery.
• Post-operative infection.
• Poor post-operative healing of wounds, especially in case of diabetic patients.
• Paralysis caused by surgery is a possibility, especially in case of brain or spinal surgery.
• Less than satisfactory outcome after surgery is a possibility if the problem was worse than anticipated or due to development of complications during surgery which necessitated cutting short the procedure. Inexperience of the surgeon may be the reason for poor results of surgery.
• The risk of death is there even in minor surgeries, although compounded in more complicated surgeries.

Parkinson’s patients, because of their frailty, advanced age, lowered immunity, medication, complications, and/or other diseases, are more likely to be at risk while undergoing surgery.

Surgery for Treatment of Parkinson’s Disease

Specific surgery to control the symptoms of Parkinson’s disease may be considered when medication becomes less effective or the side effects become intolerable.

Any of the three available surgical procedures may be undertaken.

1. Ablative surgery. A clearly-defined area of the brain affected by PD is isolated and destroyed by a heated probe (electrode) or a super-cooled probe (cryosurgery). Either a pallidotomy or a thalamotomy is done by this procedure.
2. Deep brain stimulation (DBS). The subthalamic nucleus is inactivated by an implanted electrode.
3. Transplantation or restorative surgery -  stem cell therapy.

Risks of Parkinson’s Disease Surgery

In addition to the risks associated with any surgery, these procedures carry some additional risks such as :

• Speech problems, visual defects, and other complications if the electrodes are placed too near to other brain regions.
• Allergic response to implanted material.
• Mechanical or electrical problem with the implant.
• Secondary surgery may become necessary for removal of the implant in case of breakage or malfunction.
• Intracranial hemorrhage (bleeding inside the brain).
• Neurological complications.
• Seizures.
• Confusion.
• Delirium.
• Headaches.
• Dizziness.
• There may be no improvement or there may be worsening of symptoms after surgery.
• Abnormal involuntary movements (chorea, dystonia, dyskinesia).
• Tingling and numbness.
• Paralysis.
• Stroke.
• Coma.
• Death.

]]> http://pdring.com/risks-of-surgery-in-parkinson%e2%80%99s-disease.htm/feed 0 http://pdring.com/complementary-alternative-treatment-for-parkinsons-disease.htm http://pdring.com/complementary-alternative-treatment-for-parkinsons-disease.htm#comments Tue, 24 Aug 2010 23:57:03 +0000 Dr. Chris http://pdring.com/?p=246 When considering any type of alternative treatment for Parkinson’s disease, one very important point needs to be kept in mind – there is as yet no cure for Parkinson’s disease. The various treatment options available can only help to treat the symptoms of the disease and provide some degree of relief.

Treatment by means other than conventional Western medicine (allopathic medicine) falls under the banner of complementary and alternative medicine (CAM). These are considered as natural therapies. Many natural forms of treatment are based on ancient systems of healing as were practiced in India, China, Africa, Tibet, and the Americas.

The basic difference between conventional and alternative medicine lies in the understanding of disease. Conventional medicine considers health as absence of disease. Disease may be caused by aging, pathogens, or biochemical imbalances in the body and is normally treated by medication or surgery. Alternative medicine, however, considers health as a perfect balance between the physical, emotional, and spiritual aspect of a person. Any disturbance that upsets this balance results in ill health. Alternative treatment aims to restore this balance by enhancing the body’s own defenses.

Reasons for Trying Complementary Treatments for Parkinson’s Disease

When faced with a chronic, progressive, and debilitating illness such as Parkinson’s disease, which requires lifelong treatment with drugs, many people will consider alternatives. Some of the reasons for this include :

• Natural treatments are thought of as being safe.
• The considerable side effects due to conventional medicines.
• Conventional treatment is not providing much relief.
• Unwillingness to continue with long term treatment as is necessary in PD.
• The expense involved in long term drug treatment.
• The mistaken belief that drugs stop providing relief from PD symptoms when continued for too long.
• Unjustifiable claims in advertisements about the ability of natural products to cure the disease.

Caution in Treating Parkinson’s Disease with Natural Therapies

• Stopping conventional PD drugs to try natural therapies is never advisable. Refer to Quitting Parkinson’s Disease Drugs.
• Natural treatments may be tried along with conventional therapy only after consultation with the doctor.
• Treatment should be done only under the guidance of trained and experienced professionals in complementary medicine.
• Herbal and natural preparations should be taken with caution as they may contain toxic substances or ingredients which may cause interaction with the PD drugs.
• Some herbal preparations may contain natural forms of levodopa but this will not be in the purified form, neither can the exact dose be controlled.
• Contrary to belief, certain natural remedies do have side effects.
• Natural therapies that involve manipulation of the body may result in injury.
• Many claims made about complementary therapies have not been substantiated with reliable clinical trials. The possibilities of side effects and long term complications from using these natural remedies have therefore not been verified.

Types of Natural Treatments for Parkinson’s Disease

• Biologically based therapies include diet and herbal therapy.
• Energy therapies include Reiki, Therapeutic touch, yoga, tai chi, and magnet therapy.
• Mind body medicine and techniques include meditation, relaxation techniques, hypnosis, biofeedback, and guided imagery.
• Manipulative and body based therapies include chiropractic, massage, reflexology, physical therapy, and postural re-education. While physical therapy and chiropractic are based on sound medical principles, there are practitioners within these disciplines who practice alternative techniques that have not been scientifically verified.
• Whole medical systems include Ayurveda, Traditional Chinese medicine, Homeopathy, and Naturopathy.

However, the possibility should be kept in mind that the drug obtained from such sources is cheaper because it is a counterfeit or fake. This could mean that it may not have all the necessary ingredients, the proportions may be wrong, or it may contain harmful substances. In spite of taking the drugs as prescribed by the doctor, the patient may have slow or no improvement at all or may even deteriorate drastically.

Counterfeit and Cheap Parkinson’s Medicines

• Buying drugs from foreign sources may be cheaper but you can never be sure about the quality or efficacy of such drugs. Local government regulations may be significantly different from your country of origin and counterfeit drugs are not monitored for quality control.

• Cheaper drugs may actually be counterfeit, fake, or adulterated drugs, where useless or toxic substances could be substituted for the actual ingredients. Rather speak to your doctor about generics if you cannot afford your current drug regimen.

• Parkinson’s disease patients are heavily dependent upon their medicines to control their symptoms. Even a slight amount of dose alteration can produce severe fluctuations in their symptoms. With counterfeit medicines, you can never be sure about the exact composition of the drug, which can play havoc with the patient’s system. Either too little or too much of the active ingredient can be equally harmful.

• With tampering of the drug, unknown substances may be present in the drug, the effects of which can be dangerous. This can cause drug interactions with your regular PD medicines or other medication.

• There may be no improvement in a patient’s symptoms where previously there was good control of symptoms. Side effects and even an overdose is a possibility.

• New complications may arise which were not present earlier.

• Foreign drugs may contain substances which have not been approved as being safe or effective within your country of residence.

• It is illegal to bring in such drugs into the country and in case of any problem arising from the use of such drugs you will not have recourse to any corrective action.

• In the event that these drugs contain illicit substances, you may be convicted for the possession of narcotic substances.

Buying Cheap or Counterfeit PD Drugs

You may inadvertently acquire counterfeit drugs by :

• Ordering drugs from an online agency/pharmacy (over the internet).
• Buying drugs while holidaying overseas.
• Acquiring drugs from the local “black market”.
• Genuine but stolen drugs which are altered and then sold back into the distribution system.
• Genuine but expired drugs which are sold after re-packaging and changing the expiry date.
• Genuine drugs acquired from patients have got them free and sold them for a minimum price.
• Pharmacies may unknowingly keep counterfeit drugs supplied by dishonest wholesalers.

How to Avoid Using Counterfeit Drugs

While it may seem obvious, many consumers buy fake drugs unknowingly. These are some of the measures to ensure that you are only using genuine PD drugs as prescribed by your doctor.

• Avoiding buying medicines from doubtful online agencies.
• Buy medicines from reputable pharmacies.
• Be alert while buying medicines, taking care to look at the packaging and expiry dates.
• Being aware about the shape, color, size or other characteristics of medicines which are taken regularly.
• Avoiding buying medicines from foreign sources. Carry extra medicines while holidaying abroad and in the event that you need to acquire more medication, visit a reputable pharmacy in the area.

Taking more than his prescribed dose of any medicine can affect each individual differently and the effect will also depend upon the type of medicine ingested as well as the quantity. Varying effects may be seen when the medicine is combined with other drugs, alcohol, or if it is taken along with food or on an empty stomach.

Causes of Drug Overdose in Parkinson’s Disease

• A Parkinson’s disease patient may be old and forgetful. A multiple drug regime may cause further confusion. Chances of repeating a dose is possible in such patients.
• Elderly patients may take the wrong medicine or incorrect and excessive dose without being aware of it.
• A patient may take double the dose to make up for a missed dose.
• Parkinson’s disease patients often suffer from depression. A large dose of medicine may be taken in an attempt to commit suicide.

Symptoms of Parkinson’s Medicine Overdose

The symptoms of overdose of any drug could be an aggravation of its normal action. The severity of symptoms is largely dependent on the amount of drug taken.

1. Levodopa or a combination of levodopa/carbidopa is the most common drug prescribed to treat symptoms of Parkinson’s disease. An overdose of this drug can cause nausea, vomiting, increased heart rate, palpitations and irregular heart beats (arrhythmias). Confusion and agitation may also occur.
2. Overdose with a dopamine agonist such as ropinirole may cause symptoms such as nausea, vomiting, sweating, dizziness, fainting, muscle spasms, chest pain, confusion and hallucinations. Symptoms of overdose with pramipexole, another dopamine agonist, are not known but may include any of the above.
3. MAO-B inhibitors such as selegiline overdose may induce hypotension (low blood pressure) and agitation, although definite effects of overdose have not been seen with selegiline. Headache, drowsiness, dizziness, chest pain, respiratory depression and convulsions are other possible symptoms.
4. Overdose with COMT inhibitors such as entacapone or tolcapone have not been reported but a large enough dosage could cause abdominal pain, diarrhea, nausea, vomiting, dizziness, respiratory depression and convulsions.
5. Amantadine can result in an overdose even in fairly small amounts. It can cause hypertension (high blood pressure), arrhythmias, respiratory distress, kidney problems, insomnia, agitation, confusion, disorientation, delirium, convulsions, coma or even death.

Treatment of Parkinson’s Disease Drug Overdose

Immediate medical care is very important for successful treatment of any drug overdose.

The treatment will depend upon the medicine taken (refer to Drug Therapy in Parkinson’s Disease), amount ingested, time elapsed since then, and also to a certain extent upon the age of the patient. Some of the measures may include :

• General supportive care.
• Intravenous fluids.
• Gastric lavage or pumping of the stomach.
• Inducing vomiting.
• Activated charcoal.
• ECG to monitor the heart, especially for arrhythmias.
• Specific antidotes, if available.
• Treatment of complications.

The possibility of multiple drug involvement should be kept in mind, especially if overdosing is suspected to be intentional. Refer to the article on Other Drug Interactions with Parkinson’s Disease Medicines.

Further management will be guided by the reason for overdose – accidental or intentional.

What is Drug Interaction?

Medicines are used to treat certain conditions or illnesses, but when two or more medicines are used simultaneously, they may interact with each other and cause complications or unwanted side effects. Drug interactions may occur with prescription drugs, over-the-counter (OTC) medicines, herbal remedies, or dietary supplements, so it is important that the patient realizes the dangers of mixing drugs without consulting a doctor.

Parkinson’s Disease Medicines

The drug therapy most commonly used in Parkinson’s disease usually consists of the following :

• Levodopa
• Levodopa + peripheral decarboxylase inhibitors such as carbidopa and benserazide.
• Dopamine receptor agonists – pramipexole, ropinirole, and rotigotine.
• MAO-B inhibitors – selegiline and rasagiline.
• COMT inhibitors – entacapone
• Anticholinergics – benzhexol and orphenadrine
• Amantadine.

Drug Interactions with Parkinson’s Disease Medicines

Levodopa

Since this is the most widely used medicine in Parkinson’s disease, its drug interactions should be understood by all Parkinson’s patients. Certain medicines decrease effectiveness of levodopa hence the dose of levodopa may have to be adjusted if used together. These include

• Anticholinergics – sometimes used in addition to levodopa for treatment of symptoms in Parkinson’s disease. Over-the-counter cough and cold medicines contain anticholinergics such as diphenhydramine, chlorpheniramine, and phenylephrine.
• Antispasmodics used for treating stomach or uterine cramps also contain anticholinergics such as dicyclomine and hyoscyamine.
• Anti-allergic medicines (like anti-histamines)
• Antiepileptic drugs such as phenytoin
• Sedatives such as diazepam, lorazepam and alprazolam.
• Multivitamins, specially vitamin B-6 or pyridoxine, and minerals such as iron.
• Tricyclic antidepressants such as amitriptyline
• Metoclopramide – used to control nausea and vomiting.

Certain medicines help to increase the effect of levodopa. They include

• Medicines containing acetaminophen, used for pain, headache, and fever.
• Antacids and other medicines containing aluminum, calcium, and magnesium.

The above medicines should not be used to enhance the effect of levodopa.

Levodopa may potentiate the action of antihypertensives, causing excessive lowering of blood pressure when used concurrently. Levodopa may cause severe hypertensive reactions if taken by patients treated with MAO (monoamine oxidase) inhibitors such as furazolidone or procarbazine within the last 14 days.

Other Parkinson’s Drugs

Similar drug interactions are possible with all other medicines used in Parkinson’s disease. In addition,

• Alcohol intake may cause CNS depression when used along with Parkinson’s disease medicines.
• Antibiotics such as ciprofloxacin, norfloxacin, and ofloxacin may cause drug interactions with pramipexole, ropinirole, or rotigotine.
• Entacapone may react with antibiotics such as ampicillin, erythromycin, and chloramphenicol.
• Narcotic pain relievers such as codeine may react with entacapone or other drugs.
• Quinine or quinidine may interfere with renal clearance of amantadine.

Various other drug interactions are possible and you should consult with your doctor before taking any other medication or supplement, whether an OTC (over-the-counter) medicine, scheduled drug or a herbal remedy.

What are stem cells?

Stem cells are immature cells that have the potential to differentiate into any type of mature cell in the body. The sources of stem cells being researched are :

• Embryonic stem cells from fertilized eggs– they can be made to develop into any type of cell.
• Neural stem cells from embryonic or adult brain– they develop only into nerve cells.
• Mesenchymal stem cells from other tissues.
• Immature stem cells from human (umbilical) cord blood.

Replacement of the degenerated neurons, in a case of Parkinson’s disease, by stem cell transplantation is the basis of treatment that is being studied. The concept is to take stem cells and grow them into neurons, which can then be transplanted into the brain of the patient.

Possibilities of Stem Cell Therapy as a Parkinson’s Cure

The choice of treatment offered to a patient with Parkinson’s disease all have their own limitations.

• Drug therapy is the first line of treatment but they have various side effects and their efficacy decreases as the disease progresses.
• Surgery offers no significant additional benefits.
• Embryonic mesencephalic tissue transplantation has been tried but the results are unstable and there are not enough embryonic donors.

In this scenario, stem cell therapy offers hope, not only for treatment of symptoms of Parkinson’s disease, but possibly for the reversal and halting or slowing down the progression of the disease.

Dopamine cells have been successfully transplanted in the brain of patients with Parkinson’s disease which have led to initial improvement of symptoms such as tremor, slowness of movement, rigidity, and difficulties in balance and posture.

In vitro engineering of stem cells to dopamine neurons, prior to implantation in the brain of a patient with Parkinson’s disease, is being researched to overcome the ethical and practical issues of using fetal dopamine neurons.

The finding of neural stem cells in the adult brain has opened up possibilities of using the patients own neural stem cells to grow dopamine neurons for transplantation into his brain, thereby avoiding the issue of an immune reaction. However, other factors have to be considered such as whether surgery is advisable on the already diseased brain of a patient with Parkinson’s disease.

Limitations of Stem Cell Therapy as a Parkinson’s Cure

There are various ethical, practical, safety and technical issues associated with stem cell therapy.

• Shortage of suitable donor tissue is a major issue in cell replacement therapy in Parkinson’s disease.
• The ethical issue of using fetal dopamine neurons for transplantation into the brain of a patient with Parkinson’s disease.
• Authentic dopamine neurons with correct midbrain identity need to be developed to be able to treat Parkinson’s disease patient effectively.
• Treatment with transplanted dopamine cells gives good initial response but the transplanted cells may become diseased over time.