Drug therapy is the most effective treatment for Parkinson’s disease. No medication is needed in the early stage, but if the disease affects the patient’s daily life and work, medication can be administered, adhering to the medication principle of “a long and slow flow, not seeking full effect” and emphasizing the individualization of medication. Doctors should give different medications to patients according to their gender, age, symptoms, severity of the disease and response to medications, starting with small doses to achieve the best efficacy with the least side effects, and then maintain the medication. Hu Guohua, Department of Neurology, The Second Hospital of Jilin University, Jilin, China, e.g., methyldopa treatment is often started with a small dose of 125 mg orally, 3 times a day, and then 250 mg/day every 7 days, while the number of times of taking the drug is increased to 4 to 5 times a day. Pre-meal dosing is more effective than post-meal dosing, and it is generally recommended to take the drug 1h before or 2h after meal. Patients should strictly follow the doctor’s instructions to take medication, specify the time and dosage of medication, and develop good compliance. When there is a shortage of medication, the source of medication should be replenished in a timely manner. Medication has certain side effects. Side effects of amantadine include dry mouth, decreased secretion of saliva and sweat, dilated pupils, blurred vision, constipation and urinary retention. Amantadine side effects include restlessness, insomnia, dizziness, headache, nausea, reticular bruising of the lower extremities, and ankle edema. The adverse effects of Medobarb because of peripheral decarboxylation are multifaceted, such as digestive system side effects such as nausea, vomiting, abdominal discomfort; cardiovascular system side effects such as cardiac arrhythmia, upright hypotension; urinary system side effects such as urinary retention, incontinence, aggravation of constipation, etc.; neurological system can be manifested as uneasiness, insomnia, hallucinations, delusions, etc. [1]. After taking the drug, patients should be instructed to rest in bed for 20-30 minutes or take morpholine to reduce the symptoms, and pay attention to the observation of heart rate and heart rhythm. Complications such as fluctuation of symptoms, movement disorders and psychiatric disorders may occur with long-term use of methyldopa, usually after 4 to 5 years of use of the drug. It is forbidden to use levodopa alone together with vitamin B6 because the latter is a coenzyme of dopa decarboxylase, which can accelerate the decarboxylation of dopa outside the brain, decrease the concentration of levodopa in the blood, reduce the amount of levodopa into the brain tissue and reduce the therapeutic efficacy, as well as increase the peripheral side effects of levodopa. The combination of monoamine oxidase inhibitors and levodopa can lead to a sudden rise in blood pressure, diazepam, phenothiazine, haloperidol, colestipol, opium poppy, phenytoin, rifampicin and so on can antagonize the effect of levodopa, and should be prohibited. After the occurrence of adverse reactions, patients do not need to be nervous, do not suddenly reduce the dose or stop the drug, should consult the doctor in time to adjust the treatment. Most of the patients are able to take the drug consistently after adjusting the dosage.