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General Knowledge on the Use of Medicines

Proper Use of Medicines

Medicines can treat illnesses and alleviate symptoms, but they also give rise to adverse side effects. Improper use of medicines brings potential health hazards. Members of the public should therefore acquire knowledge on the efficacy of medicines and use them as instructed by doctors or pharmacists.
Patients should take medicines prescribed by their doctor according to the dosing schedule, and make no arbitrary increase or decrease on the frequency and dosage of medication. Overdose may lead to poisoning or even death, while underdose cannot relieve the medical conditions. You should attend follow-up appointments as scheduled, and tell your doctor clearly your reaction to the medication. The doctor will then, with reference to your medical conditions, make upward or downward adjustments to the dosage or switch to a more suitable medicine. Do not recommend to others the medicines prescribed by your doctor specifically for you because similar symptoms do not necessarily represent the same illness and physical conditions vary among individuals. Indiscriminate self-medication would not only delay the treatment but also bring about health risks due to adverse side effects.

Advice on Medication

Common side effects of medicines include nausea, constipation and dizziness. Not everyone would experience the same side effects, and most of them would subside after using the medicine for some time. If in doubt, consult a doctor, pharmacist or dispenser.
Various medicines may interfere with each other and some may subject to the influence of diet, and this is what we call “contraindications”. For example, tranquillisers should not be taken with alcoholic drinks. You should therefore tell your doctor during medical consultation what medicines you are taking and take note of the label instructions to avoid danger.

Generally speaking, the following should be borne in mind when taking medicines:

  1. Have a clear understanding of how the medicines should be used (e.g. to be taken orally, placed under the tongue, chewed before swallowing, inhaled, inserted rectally or for external application, etc.).

  2. Read the drug labels carefully, and pay attention to details including dosage, dosing schedule, efficacy, contraindications and side effects. For example, certain medicines may induce drowsiness and hence possible danger to a person if he/she has to operate machinery and drive a car after medication.

  3. Unless instructed by your doctor, do not take multiple drugs, including Chinese drugs and oral contraceptives, at the same time to avoid medicinal interference.

  4. In case of adverse reactions, such as rash, headache and abdominal pain, stop the medication and consult your doctor immediately.

  5. Pregnant and breastfeeding women should not use or take medicines unless instructed by a doctor, as some medicines may pass into the placenta or breast milk and pose adverse impacts to the foetus or the infant.

  6. Check expiry dates of medicines and discard expired or spoiled medicines.

  7. Medicines in general should be kept in a cool and dry place, but some of them, such as insulin products and oral antibiotics, should be kept in the refrigerator as specified in the label. Do not store medicines in a freezer compartment, as this may affect the efficacy. Medicines should be stored properly to avoid the danger of mistaken consumption by children.

  8. Most orally taken medications such as tablets should be swallowed whole with water. Tablet should not be broken into pieces or crushed before taking unless as directed by doctor or healthcare professionals such as pharmacist have been consulted.

Medicine Labels

Effective from 1 January 1995, medicines prescribed by a doctor for a patient should have the name of the medicine and other relevant information shown clearly on the medicine bag or bottle. For clinics and hospitals under the Department of Health and the Hospital Authority, most dispensaries have undergone computerisation and information given on the medicine label includes name of the medicine, method of use, dosage, name of patient, date of prescription, name of the clinic or the hospital and special instructions, if any. The purpose of providing such information is to inform members of the public of the knowledge on the medicines they are using to ensure proper application as well as serving as reference and means of contact for healthcare personnel in times of emergency. Members of the public should refrain from indiscriminate self-prescription and self-medication if they do not have a full picture of the situation, as this may result in health hazards.

Classification and Control of Drugs

According to the laws of Hong Kong, medicines are classified into three main categories according to the severity of the diseases they intend for and the magnitude of the side effects they cause. Medicines in different categories have to be sold in different registered retailers under different specified conditions outlined as follows:

Category 1: Medicines in this category must be dispensed and sold on doctor’s prescription in registered dispensaries under the direct supervision of registered pharmacists.

Examples include antihypertensive medicines, oral antidiabetics and tranquillisers. Such “prescription medicines” are used to treat serious diseases. Incorrect dosage or improper use may bring about serious health damage.

Dispensaries with registered pharmacists in residence display an identification logo bearing a red ‘Rx ’ set against a white background.

According to the Pharmacy and Poisons Ordinance, medicines in Category 1 should be labelled with the words “Prescription Drug 處方藥物”.

Category 2: Medicines in this category do not require doctor’s prescription but have to be sold in registered dispensaries under the direction and supervision of registered pharmacists. The method of use and dosage must be followed to avoid health risks.

According to the Pharmacy and Poisons Ordinance, medicines in Category 2 should be labelled with the words “Drug under Supervised Sales 監督售賣藥物”.

Category 3: Medicines in this category can be sold in dispensaries or drug stores without resident pharmacists and examples include drugs for common cold, antipyretics and painkillers. They are often used to treat or alleviate minor illnesses and their side effects are fewer. Despite this, members of the public have to bear in mind that improper use of such medicines may also bring about undesirable side effects. If in doubt, consult your doctor and refrain from discriminate self-medication.

According to the laws of Hong Kong, anyone who contravenes the above rules in selling medicines may be prosecuted. The offender may be subject to fine and imprisonment upon conviction, and he/she may also have to face disciplinary actions against professional misconduct. You are welcome to call 2572 2068, a 24-hour hotline set up by the Department of Health to report any information on illegal sale of medicines.

General Knowledge on Medicines and Medicine-Related Laws

  1. If you want to obtain more information on medicines, please refer to other items under "Heath Topic" and “General Knowledge on Medicines” at this website.

  2. Medicine-related laws in Hong Kong include “Pharmacy and Poisons Ordinance”, “Dangerous Drugs Ordinance” and their subsidiary legislations. If you want to know more about such laws in Hong Kong, please visit the Government Publications Centre for publications on relevant legal subjects.

  3. For general knowledge on prohibited drugs, please contact the Narcotics Division via their enquiry hotline at 2366 8822.

Drug Office
Department of Health
Jun 2017