Arpicolin syrup contains the active ingredient procyclidine hydrochloride, which is a type of medicine called an anticholinergic. (NB. Procyclidine is also available without a brand name, ie as the generic medicine.) Anticholinergic medicines (sometimes also called antimuscarinics) work by preventing the activity of a neurotransmitter called acetylcholine.
Neurotransmitters are chemical compounds that are found in the brain and nerves. They act as chemical messengers between the nerve cells. There are many different neurotransmitters in the body and these have various different functions. Several diseases and conditions involve either overactivity or underactivity of certain neurotransmitters.
In Parkinsons disease, there is a deficiency of a neurotransmitter called dopamine in the brain. Normally there is a balance between the activity of dopamine and the activity of acetylcholine in the brain. However, in Parkinson's disease, the deficiency of dopamine causes overactivity of acetylcholine. This causes some of the symptoms of the disease.
Procyclidine works by blocking the receptors that acetylcholine acts on. This reduces the activity of the acetylcholine, and helps restore the balance of acetylcholine and dopamine in the brain. In this way, procyclidine helps control some of the symptoms of Parkinson's disease. It is most effective at reducing the tremor and rigidity associated with the disease, but it has little effect on the slow movements (bradykinesia).
By contrast, some psychiatric illnesses, for example schizophrenia, are associated with overactivity of dopamine in the brain. Antipsychotic medicines that are used to treat these diseases work by decreasing the activity of dopamine in the brain. However, because they decrease dopamine they can produce side effects that resemble the symptoms of Parkinson's disease. These side effects are known as extrapyramidal side effects, and include abnormal face and body movements, restlessness and tremor. Procyclidine can be used to treat this type of side effect.
This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.
Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.
The side effects listed above may not include all of the side effects reported by the drug's manufacturer.For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.
It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to ensure that the combination is safe.
Many groups of medicines have anticholinergic effects. If this medicine is taken in combination with any of these, there there is an increased likelihood of anticholinergic side effects, such as blurred vision, dry mouth, constipation and difficulty passing urine. Other medicines with anticholinergic effects include the following:
This medicine has an opposite effect to cholinergic medicines, which work by increasing the activity of acetylcholine. If this medicine is used in combination with medicines that have cholinergic effects, the medicines may oppose each others effects, making one or both less effective. Medicines with cholinergic effects include the following:
Procyclidine can reduce the motility of the gut and may therefore reduce the absorption of certain other medicines taken by mouth, for example levodopa (L-dopa) for Parkinson's disease and the antifungal medicine ketoconazole. If you are taking levodopa and start taking this medicine as well, let your doctor know if your levodopa seems to be less effective.
Procyclidine may reduce the effects of the following medicines on the gut:
The antidepressant paroxetine may increase the blood level of procyclidine and this could increase the chance of side effects. If you start taking paroxetine with procyclidine and you get new or increased side effects, such as blurred vision, dry mouth, constipation or difficulty passing urine, you should let your doctor know. Your dose of procyclidine may need to be reduced.
If you experience a dry mouth as a side effect of this medicine you may find that medicines that are designed to dissolve and be absorbed from under the tongue, eg sublingual glyceryl trinitrate (GTN) tablets, become less effective. This is because the tablets do not dissolve properly in a dry mouth. To resolve this, drink a mouthful of water before taking sublingual tablets.
Procyclidine tablets are also available without a brand name, ie as the generic medicine.