Notes when using cough medicine

Coughing is a reflex of the body to clean the airways, not to accumulate secretions, irritants, foreign objects, bacteria... This is a mechanism to protect the respiratory system. However, if the cough affects daily activities, it is necessary to use cough medicine.

Normally, cough reflex will occur when having cold, influenza virus infection, allergic conditions, diseases affecting the respiratory tract (asthma, bronchitis, pneumonia, sinusitis, otitis media...), smoking or passive smoking, air pollution, gastroesophageal reflux disease. Some drugs such as ACE inhibitors used to treat high blood pressure can cause cough.

Notes when using cough medicine

Drugs acting on phlegm:Are all drugs that change the characteristics, properties, quantity and adhesion of phlegm on the surface of the airways. Normally, there is always a layer of mucus on the airways, with moderate viscosity, moisture and quantity to protect the respiratory tract. But when the respiratory system is diseased, this layer of mucus changes its properties, becomes sticky, thick and then it is called phlegm. Drugs that act on phlegm include phlegm thinning drugs and phlegm-dissolving drugs.

Medication consultation for patients. Photo: TM

Expectorants are drugs that increase secretions (mainly water) on the surface of the respiratory tract. This increased secretion causes the phlegm to have more dissolved water, which increases the volume of phlegm, making it thinner. Typical drugs in this group are guaifenesin, sodium benzoate, terpinhydrate... Expectorants are drugs that act directly on phlegm, making it less thick, easier to expel through the cough reflex... these are drugs: acetylcysteine, ambroxol, carbocisteine, bromhexine...

The medicine that acts on phlegm only really works when taken with water. The medicine will not be most effective if you do not drink enough water. Water is a substance that directly increases secretions in phlegm, increasing the thinness of phlegm. Usually, an adult should drink at least 1.5 liters of water per day.

Not all cases require expectorants, but the level of phlegm must be determined before using the medicine. For example, a child under 1 year old has a cough, if there is excessive phlegm secretion, lots of wet and crackling rales, and has severe pneumonia, then using medicine at this time will make the pneumonia worse. Because when using medicine, the lungs will have more fluid, more crackling sounds, and more difficulty breathing...

Or in the case of patients with chronic obstructive pulmonary disease (COPD), the amount of phlegm secreted during acute attacks is very intense. If these drugs are continued, it will be very disadvantageous, because the cough will increase and the difficulty in breathing will become more obvious. The problem at this time is to reduce phlegm secretion in order to control the amount of phlegm allowed before deciding to use phlegm-acting drugs at a later time.

Determining the level of phlegm and when to use it depends entirely on the doctor's level of expertise, carefulness, meticulousness in examination as well as treatment experience.

Cough suppressant:Drugs that reduce cough by inhibiting the cough center such as codeine, pholcodine, dextromethorphan. Of which, codeine and pholcodine have addictive, analgesic and mild inhibitory effects on the respiratory center. Dextromethorphan is not addictive and has no analgesic effect.

Cough medicines containing codeine are for adults only, not for children because they cause respiratory depression. In particular, cough medicines containing codeine are contraindicated for children under 18 years of age who have just had their adenoids removed and/or scraped (used for pain relief). The above cough medicines are only used in cases of dry cough without phlegm (cough due to flu, cough due to irritation, allergy), severe cough that makes the patient tired, sleepless, not for cases of cough with phlegm (in chronic bronchitis, bronchiectasis); not for people with respiratory failure, asthma, children, pregnant and lactating women.

Antihistamines:Some antihistamines for allergies (first generation H1 antihistamines) also have soothing, cough-suppressing and sedative effects such as diphenylhydramine, chlorpheniramine, alimemazine, promethazine. The drugs are used to treat dry coughs caused by allergies and irritation.

The main disadvantage of these drugs is that they cause drowsiness due to their effect on the H1 receptors in the brain, so they are disadvantageous when used during the day but are advantageous when used at night. They should not be used when driving, flying, operating machinery, etc. This drug also has the effect of drying out secretions, making it difficult to expel phlegm, and can cause phlegm blockage, so they should not be used in cases of cough with phlegm or asthma.

Use the lowest effective dose for the shortest possible time to minimize side effects. Do not combine cough suppressants with expectorants as this will increase the production of phlegm and will not be coughed up.

In addition, anesthetics, due to their anesthetic effect on nerve endings that cause cough reflex, also reduce cough, such as active ingredients such as benzonatate, menthol, lidocaine... used through inhalation or sucking. Cough suppressants have a protective effect, covering the sensory centers in the throat, mostly glycerol...

It should be noted that cough medicines that combine many ingredients (neocodion, codepect, atussin, arsiba...) in addition to side effects can cause adverse interactions with other drugs when used at the same time.

According to Giaoducthoidai