Drugs acting on respiratory system

Therapeutic drugs treated respiratory diseases 

Symptoms Therapeutic drugs Cough Ⅰ. Antitussive drugs Sputum Ⅱ. Expectorant drugs Asthma Ⅲ. Antiasthmatic drugs

Classification of drugs acting on respiratory system

Ⅰ. Antitussive drugs 1. Centrally acting: Codeine 2. Peripherally acting: Benzonatate

Ⅱ. Expectorant drugs1. Sputum-diluting drugs: NH4Cl、KI 2. Mucolytic drugs: Ambroxol

Ⅲ. Antiasthmatic drugs 1. Bronchodilators: (1)B 2 receptor agonists: Salbutamol (2)theophyllines: Aminophylline (3)muscarinic antagonists: Ipratropine 2. Anti-inflammatory drugs: 1)glucocorticosteroids: Budesonide 2)mediator release inhibitors Disodium cromoglycate

Antitussives Centrally acting  Addictive drugs:– Codeine Non-addictive drugs: Dextromethorphan

 Pentoxyverine Peripherally acting  Benzonatate

Narcotic Antitussives Pholcodine

Pharmacological effects

 Its cough suppressant effects is similar with codeine

 mild sedative effect

 little or no analgesic effects

 lower potential for dependence

Mechanism of action

It acts primarily on the central nervous system (CNS), causing depression of the cough reflex, partly by a direct effect on the cough centre in the medulla.

Side effects

• Dizziness

• Gastrointestinal disturbances such as nausea or vomiting.

• constipation, drowsiness, excitation, ataxia and respiratory depression ( after large doses)

• Increased levels of IgE-antibodies,

• Increase the risk of anaphylaxis to neuromuscular blocking agents used during anaesthesia.

Drugs used in the treatment of asthma- Classification in Respiratory system 

 Relievers - Bronchodilators

 B2 agonists

 short-acting: salbutamol, terbutaline

 long-acting: salmeterol, formoterol

 Anticholinergics (muscarinic antagonists): ipratropine

 Xantines (theophyllines): aminophylline

 Preventers - Anti-inflammatory drugs

 Glucocorticosteroids:

 Inhaled steroids: beclomethasone, budesonide, fluticasone

 oral steroids: hydrocortisone, prednisone, dexamethasone

 Leukotriene (LT) receptor antagonists (leukotriene modifiers):

 LT antagonists: montelukast 

 5-lipoxygenase inhibitors: zileuton 

 Inhibitors of mediator release: cromolyn sodium, nedocromil

XANTHINES   Pharmacological effects Inhibiting phosphodiesterase; Blocking adenosine receptors;
 Increasing catecholamine release;Immunomodulation; Increasing respiratory muscle
contractility; CNS stimulation, diuretic, gastric acid ecretion,

 Antiasthmatic drugs Glucocorticosteroids Systemic: Hydrocortisone Prednisone Dexamethasone
Inhalation: Beclomethasone dipropionate Budesonide Fluticasone propionate Mometasone furoate

 Pharmacological effects Antiinflammation: inhibiting inflammatory cell activities, antibody production, mediator

release Clinical uses As first-line drugs, currently Controlling chronic symptoms Ineffective for acute symptoms

Adverse effects

Local: oropharyngeal candidiasis－using spacer Systemic effects Hypercorticism-like syndrome: central obesity(moon face, buffalo hump, etc.); hypertension; glycosuria, hypokalemia; etc.

 Increasing susceptibility to infections Ingestive system: peptic ulcers, etc. – Cardiovascular system: hypertension,arteriosclerosisMyopathy and osteoporosis: vertebral compression fractures, spontaneous fractures,especially in postmenopausal women drenal suppression