What Is an Antitussive?

Cough is a major symptom of respiratory diseases. Cough is a protective reflex, which can promote the discharge of sputum and foreign bodies in the respiratory tract and keep the respiratory tract clean and unobstructed.

Drug Name: Antitussive
Foreign name: antitussive drug

Whether prescription drugs: Non-prescription drugs
Main indications: Vigorous sputum-free cough

About Antitussives

Cough is a protective reflex. A slight cough can help clear the sputum and foreign bodies in the trachea, and it will relieve naturally. Generally, you do not need to take cough medicine. Strong and frequent cough, especially dry cough, can affect rest and sleep. Even exacerbating the condition and causing other complications, it is necessary to add antitussive and phlegm drugs while treating the cause.

Research Progress on Antitussives

The current application of antitussives has limitations, and many antitussives lack exact antitussive effects or have adverse reactions that are difficult for patients to tolerate. Fortunately, with further research on the mechanism of cough reflexes, scientists have discovered some drugs with new mechanisms of action. Selective opioids and opioid-like receptor agonists, capsaicin receptor (VR), tachykinin receptor (TK) antagonists, neurokinin receptor antagonists, prostaglandin synthesis inhibitors, potassium channel openers , Cl ion channel regulators, 5-TH receptor antagonists, GABA-B receptor agonists, etc. are all hot topics in research. These studies are expected to provide antitussives with more precise effects and fewer adverse effects. ^[1]

Antitussive drug categories and dosage forms

The use of central antitussives is 41%, and the use of peripheral antitussives is 59%; the use of single dosages is 45%, and the compound preparations are 55%. The difference is not large, but the use of central antitussives is independent. Sexual antitussives. It may be related to the types of hospital medicines and clinicians' medication habits. The selection of antitussive drugs requires the physician to strictly grasp the characteristics of the drug, pay attention to indications, contraindications, contraindications for contraindications, and adverse reactions, especially to grasp the specific drug composition of the compound preparation to avoid medication errors and repeated medication. At the same time, learn how to use the cough score and visual analog scoring system to evaluate the severity of cough. ^[2]

Antitussive drugs

Central antitussive

Central antitussives directly inhibit the medullary cough and produce antitussive effects. They are divided into dependent and independent antitussives.

a Dependent Antitussive:

Codeine: Directly inhibits the medullary cough center, which has a strong and rapid antitussive effect, and also has analgesic and sedative effects. It can be used for severe dry cough and irritating cough caused by various reasons, especially dry cough with chest pain.

b Independent antitussives:

Dextromethorphan: The effect is similar to that of codeine. The therapeutic dose has no inhibitory effect on the respiratory center, no analgesic effect, and no addiction. The most widely used clinically, it is suitable for cough in cold, acute or chronic bronchitis, bronchial asthma, sore throat, tuberculosis and other upper respiratory tract infections.

Pentovirin: It has a selective inhibitory effect on the cough center, and still has a mild atropine-like effect and local anesthesia effect. Large doses have antispasmodic effects on bronchial smooth muscle, and have both central and peripheral antitussive effects. The antitussive effect is about 1/3 of codeine, and it is not addictive. It has been used clinically for a long time, and is used for sputum-free dry cough and whooping cough caused by upper respiratory tract infection, which has a better effect on children than adults.

Antitussive

By suppressing any of the sensory, afferent, efferent and effectors in the cough firing arc, it plays an antitussive effect.

a Nakedine: Also known as "codeine" in the periphery. Isovarin alkaloids contained in opioids produce peripheral antitussive effects by inhibiting pulmonary reflex and releasing broncho smooth muscle spasm. It has special therapeutic value for allergic cough, spastic cough, severe and paroxysmal cough, and it can also suppress inflammation caused by respiratory secretions.

b Benproperin: a non-narcotic antitussive, its effect is 2 to 4 times that of codeine, it can inhibit peripheral afferent nerves, and it can also suppress the cough center. It is used to treat acute and chronic bronchitis and cough caused by various irritation. It is the drug of choice for severe cough. Note: After taking the medicine, transient numbness in the mouth and pharynx may appear. In addition, there are still adverse reactions such as fatigue, dizziness, and epigastric discomfort. Discontinue medication if a rash occurs during the medication.

Antitussive compound

Cough with phlegm, should be combined with expectorants such as ammonium chloride, bromhexine, acetylcysteine, etc., in order to facilitate sputum discharge and antitussive effect. There are also some compound preparations containing antitussive, expectorant, antihistamine and other drugs, which have more clinical applications.

a Compound methenamin: Capsules contain methanamin hydrochloride, narcotine, aminophylline, and chlorpheniramine maleate. It can relieve cough caused by throat and bronchial inflammation, relieve cough during asthma attacks, and is good for expectoration. Note: People with heart disease, high blood pressure or older age, glaucoma, hyperthyroidism, dysuria and those who are receiving treatment should be taken with caution. May cause drowsiness, do not drive or operate machinery.

b Keyu syrup: it has obvious expectorant and antitussive effects. Codeine has a certain degree of addiction in long-term or large-dose applications. Guaifenesin is an irritating expectorant, which can dilute sputum and easily cough up. ^[3-4]

Antitussive Use Principles

Antitussive Treatment

Cough can be caused by a variety of reasons, the key to medication is the cause of treatment. Some coughs are caused by bronchial asthma, and asthma treatment is effective; some are caused by esophageal reflux, and gastric motility drugs and antacids are effective.

Symptomatic treatment of antitussives

When the etiology treatment is not effective immediately, symptomatic treatment is needed. Patients with irritant dry cough should use benproperine and pentovirin. Patients with severe cough should prefer benproperine and dextromethorphan second. Phenproperin should be used for cough during the day, and dextromethorphan should be used for cough at night.

Antitussive combination

Cough with more sputum should be mainly expectorant, and it should not be used simply with antitussives. It should be combined with expectorants to facilitate the discharge of sputum and the antitussive effect. Cough with phlegm, should be combined with expectorants such as ammonium chloride, bromhexine, acetylcysteine, etc., in order to facilitate sputum discharge and antitussive effect.

Antitussives pay attention to adverse reactions

Dextromethorphan can cause drowsiness. Do not use it when driving a car or working at height. It should not be used by women within 3 months of pregnancy and those with a history of mental illness. Patients with glaucoma, heart failure and pulmonary congestion should use jettovirin with caution. Central antitussives are only suitable for severe sputum-free dry cough, and should be avoided in elderly, pregnant women, and children.