Cough is one of the defense reflexes of the human body, which can remove secretions and harmful factors from the respiratory tract. The cough center is located in the dorsal part of the medulla oblongata, close to the respiratory center. It is generally considered to be related to the nucleus tractus solitarius and is affected by Cerebral cortical control. The need for cough suppression depends on the clinical situation.
Under normal circumstances, mild cough will be relieved naturally with the discharge of sputum or foreign body, and it is not necessary to take cough medicine. However, frequent and severe coughing can cause discomfort to patients, affect rest and sleep, and lead to a decline in quality of life. At this time, cough suppressants should be used.
Cough suppressants are generally thought to be useful in the following situations:
1. The degree of cough is severe, which affects the quality of life of the patient, or may lead to complications such as pneumothorax, rib fracture, cough reflex syncope;
2. It is an idiopathic cough and cannot be treated for the cause, or the treatment for the cause takes a long time to take effect;
3. There is no effective treatment, such as inoperable lung cancer.
The following is a summary of common cough suppressants:
One. Central antitussives
Central antitussives are drugs that act on the cough center of the medulla oblongata to relieve cough. Antitussives are divided into dependent and non-dependent antitussives according to whether they are dependent on the drug.
Dependent antitussives refer to morphine alkaloids and their derivatives, which are the most powerful antitussives, including morphine, codeine phosphate, and phorcodine; Antitussives include dextromethorphan, pentoxaverine, benproperine, and cloperastine.
The long-term use of dependent antitussives is addictive and has respiratory depression, so its clinical application is limited [1-2].
1. Commonly used centrally dependent cough suppressants
2. Commonly used non-centrally dependent cough suppressants
Two. Peripheral cough suppressants
refers to drugs that combine with cough receptors, afferent nerves, efferent nerves, and effectors on the cough reflex arc as a point to produce an antitussive effect.
Because the drug cannot cross the blood-brain barrier and enter the central nervous system, it does not produce the opioid-like sedative effects.
Peripheral antitussives can be divided into two categories: local anesthetics and mucosal protective agents. Local anesthetics include benzonatate, noscapine, lidocaine, etc.; mucosal protective agents include licorice fluid extract and the like.
Three. Compounds
If the cough is accompanied by excessive phlegm, it should be combined with expectorants such as ammonium chloride, bromhexine, acetylcysteine, etc. to facilitate sputum discharge and antitussive effect. At this time, compound preparations containing antitussive, expectorant, antihistamine and other drugs can also be used:
Write at the end
Cough is just a symptom. To stop a cough, you must first identify the cause and choose the appropriate drug according to the cause:
Discontinue medication for cough caused by drugs, such as captopril;
If it is caused by chronic obstructive pulmonary disease and bronchiectasis, and more sputum expectoration, it is necessary to combine phlegm-reducing drugs at the same time;
For severe dry cough, especially pleurisy, cough accompanied by chest pain, or lung cancer, central antitussives such as codeine can be used.
In addition, drug selection should be based on age and physiological characteristics:
For groups with underlying diseases such as hypertension and coronary heart disease, especially the elderly, cough medicines that are harmless to the heart, liver and kidney should be selected;
Pregnant and lactating women should choose antitussive drugs that do not penetrate the placental barrier, and dextromethorphan and pholcodine should be banned or used with caution;
For children, it is best to choose a special preparation for children.
When the etiology is unknown and some serious diseases cannot be ruled out, such as early lung cancer and bronchial tuberculosis, it is also not appropriate to blindly apply cough suppressants to avoid covering up the disease and delaying diagnosis and treatment [5-6].
Typesetting: Meichao
Title image: Zhanku Hailuo
References:
[1] Zhuang Yuan, Huang Yiqi. Rational application of antitussive drugs [J]. Strait Pharmacy, 2013,09:163-165.
[2] Li Shiquan. Over-the-counter Chinese patent medicines for relieving cough and asthma should be reasonably selected according to symptoms [J]. Heilongjiang Medicine, 2013,02:297-299.
[3] Ma Fuyun, Ma Liping, Zhao Hua. A case of benproperine poisoning [J]. Chinese Journal of Pediatrics, 2000, 11:9.
[4] Liu Hongben, Ma Peiqi. Antitussive drug levoplastine and related suggestions [J]. Shanghai Medical Information Research, 2003, 01:1-4.
[5] Yang Haoyu, Li Chunping, Jiang Cai’e, Jia Fan. Analysis of the use of antiasthmatic and antitussive drugs in a patient with acute exacerbation of chronic obstructive pulmonary disease [J]. Electronic Journal of Clinical Medicine Literature, 2018 ,65:182.
[6] Gao Xiaohan. Analysis of the prescription of antitussive and expectorant drugs [J]. China Practical Medicine, 2018,15:147-148.