Drugs for Common Cold

Upper Respiratory Tract Infection

Common cold generally refers to the infection of the upper respiratory tract, i.e., nose, pharynx, larynx and trachea. This is a very common infectious disease and most of the cases are mild in nature. There are more than 200 types of viruses which can cause such infection. As common cold is caused by virus, antibiotics do not work for the disease. Patients would generally recover on their own within a week. There is no cure to common cold. Adequate rest is the key factor in preventing the infection to spread to the lower respiratory tract.

Commonly Used Drugs

Drugs that are often used for common cold include the following four categories:

1. Analgesics and antipyretics: Examples are aspirin and paracetamol. In Hong Kong, paracetamol, sold as branded products or under the generic name paracetamol, is the most commonly used analgesic and antipyretic drug. They are used for relief in fever and pain such as headache and muscle ache. They may cause perspiration and some would even irritate gastric mucosa and cause stomach upset. Therefore, they should be taken after meals. Proprietary medicines available in the market for common cold generally contain ingredients belonging to this category.


2. Antihistamines: For alleviating the symptom of runny and stuffy nose. They are also antiallergic and can be used for allergic diseases, such as nasal or skin allergies. Possible side effects include drowsiness, thirst and stomach upset. Patients should therefore drink plenty of water, take the medication after meals and refrain from alcohol, driving or engaging in dangerous activities. Drugs in this category cannot be taken with sleeping pills, tranquilisers or antispastics. For more details, please consult a doctor, pharmacist or dispenser.


3. Cough Syrup: Viral infection makes patients suffering from common cold produce large amount of secretion in the respiratory tract, giving rise to frequent coughs with sputum. The function of coughing is to expel the sputum and therefore the viruses as well. Some patients, upon recovery, would still have an itchy throat or an urge to cough when exposed to external irritation such as smoke, dust or chill. This symptom, known as dry cough, is more serious at night and affects the sleeping quality of the patient.
   
   Commonly used cough syrup can be divided into two categories according to their purposes of use:
   1. Expectorants: For increasing secretion of the respiratory tract. Such secretion would not only protect the respiratory tract mucosa but also reduce the thickness of the sputum. Thinner sputum is easier to flow and cough out, thus relieving the cough indirectly. Common expectorants include ammonium chloride, tincture of ipecacuanha and tincture of senega.
   2. Antitussives^: For relieving the cough by suppressing the central nervous system. Some antitussives contain codeine* may cause drowsiness. Special attention is therefore required during medication.


4. Other medicines intended for common cold include lozenges and medicinal mouthwash. Their purpose is to lessen throat pain and relieve some other discomforts associated with common cold.

Recommendations for safe use of cough and cold medicines in Children

• Cough and cold medicines are not indicated for children under 6 years old. If your child is suffering from symptoms of cough and cold, you should consult your doctor for the most appropriate treatment.
• Codeine* is contraindicated for all children younger than 12 years of age. Avoid the use of codeine* in adolescents 12 to 18 years of age who have other risk factors that may increase their sensitivity to the respiratory depressant effects of codeine* unless the benefits outweigh the risks. Risk factors include conditions associated with hypoventilation, such as postoperative status, obstructive sleep apnea, obesity, severe pulmonary disease, neuromuscular disease, and concomitant use of other medications that cause respiratory depression.

Storage of the Drugs

The drugs should be kept in a cool and dry place. Generally, they do not need to be refrigerated unless otherwise stated in the drug labels. Also, they should be stored properly to avoid accidents of mistaken consumption by children.

* Starting from 26 January 2024, it is a legal requirement for pharmacy to record the purchaser's personal information, including Identity Card number, when supplying codeine-containing medicines without doctor's prescription.
^ Pharmaceutical products containing pholcodine have been banned in Hong Kong since 1 January 2024 due to their benefits no longer outweigh the risks.