PULMONARY PHARMACOLOGY

Bronchodilators: relax constricted bronchiolar smooth muscle and open blocked airways. B-adrenergic receptor agonists are used to treat bronchospasm. drugs relax bronchial smooth muscle. B-adrenergic receptor agonists mimick a normal B-receptor response (which is usually stimulated by mostly epinephrine and at times norepinephrine). ALBUTEROL See diagram

(http://cvm.msu.edu/RESEARCH/PULMON/site/respiratory_diseases/diseases/Heaves/MOA_of_BDD.html)

Methylxanthines: Only salts of theophylline are used as bronchodilators (including aminophylline). http://ajrccm.atsjournals.org/cgi/content/full/167/6/813
Mechanism of theophylline.

Some bronchodilator effects: inhibits phosphodiesterases which normally hydrolyze cAMP. cAMP increases and causes smooth muscle relaxation. Also, theophylline is believed to inc. diaphragm contractions and decrease diaphragm fatigue but this has not been proven.

Mucolytic agents: alter the characteristics of respiratory tract fluids
They help reduce the viscosity of sputum (expectorated mucus mixed with serum proteins, lipids, electrolytes, calcium, and DNA from white blood cells) by depolymerizing mucopolysaccarides into smaller, more soluble molecules. Acetylcysteine (mucomyst, mocosol) is used in asthma. The free sulfhydryl group reacts with disulfide bonds in mucoproteins and breaks them up. Acetylcysteine is also a free radical scavenger that protects the airways against oxidant damage.

HSCH2CHCOOH
|
NHCOCH3 Acetylcysteine May be given orally or by nebulization


Antibiotics: Combat infections

Glucocorticoids: reduce inflammation within the respiratory tract and cause other bronchoreactivity. Two possible mechanisms: 1) enhance the action of adrenergic agonists on B2 receptors. 2) modulate eicosanoid production and reduce the synthesis of prostaglandins and leukotrienes. Prostaglandins and leukotrienes are bronchoconstrictors
PREDNISONE


Nasal decongestants: constrict dilated vessels in the nasal mucosa
What happens in the nose?
Resistance to airflow in the upper airways is regulated by autonomic control of smooth muscle within mucosal blood vessels. Allergies, viruses, and inflammatory conditions can cause these vessels to dilate which causes congestion. All act by the same mechanism but vary in duration of action. Direct application: constricts the mucosal vessels through alpha-adrenergic mechanisms. Common drugs: phenylehrine, oxymetazoline, ephedrine, xylometazoline (Goth’s medical pharmacology).

Antitussives: reduce coughing.


Norma Jean’s Drugs:
Aminophylline
Ventolin (albuterol)
Prednisone




Daria