Drugs used in treatment of Bronchial Asthma action,dose and side effects

The pharmacologic agents for treating bronchial asthma can be divided into two general categories:
(1) Drugs that inhibit smooth muscle contraction i.e. bronchodilators (quick relief medications) e.g 82 agonists, aminophylline and anticholinergics.

(2) Drugs that prevent or reverse inflammation i.e. anti inflammatory (long term control medications) e.g corticosteroid, leukotriene inhibitors and mast cell
stabilizers. These agents have a prophylactic or preventive actions.

I . Drugs used during attacks

A- B2 agonist inhalers by metered dose inhaler (MDI) Salbutamol (ventoline), terbutaline = B2 agonist (bronchodilator)
Advantages :  No side effects of systemic B2 agonist  ,, Rapid action.

Dose: 2 puffs as required (100 ug/puff) for salbutamol and (250 ug/puff) for terbutaline .

Use of MDI :
(1) The canister is shaken
(2) The patient exhales the normal expiration.
(3) The aerosol nozzle is placed to the open mouth
(4) The patient simultaneously inhales rapidly and activates the aerosol.
(5) Inhalation is completed
(6) The breath is held for 10 seconds if possible.

B- Aminophylline IV .
Dose : Loading dose: 5mg/kg (very slowly) then maintenance dose 0.5 mg/kg/hr as in cases of acute severe asthma.

C- Cortisone :

 Hydrocortisone 200 mg/6hrs IV or methyl prednisolone 40-60 mg/6hrs IV.
Action :   - reduce airway obstruction    ( Anti -inflammatory - Antiallergic )

D- Anticholinergic :
 inhaler e.g ipratrobium bromide which is a non absorbable inhaler, it may enhance the bronchodilation achieved by sympathomimetics but is slow acting (60-90 minute to peak bronchodilation).
 The dose is 20-40ug three or four times daily.

E- Adrenaline:   (it is better to be avoided)
the patient must be :  Not hypertensive Not cardiac

Dose : Solution (1/1000 - Amp), a dose of 0.3-0.5 mg.
i.e 0.3-0.5 ml. ~ S.C, it can be repeated after 20-30 minutes .

II- Drugs used in between Attacks :

A- Aminophylline
The best is long acting preparation 100-200 mg/12 hr.
i.e Anhydrous Aminophylline, e.g (Quibron) tablets 300 mg.
Advantages: Less GIT irritation, long acting.

B- Systemic B2 agonist: (bronchodilator)
* Salbutamol :  Ventoline or Salbuvent

* Terbutaline -+ Bricanyl
* Dose 2-4 mg/d (oral)
* Side effects :
 Tremors   Tachycardia (palpitation )

C- Disodium cromoglycate [intal] Inhaler :
Stabilizes the membrane of mast cell --> Decrease the release of mediators

D- Ketotifen: (zaditen), mast cell stabilizer.
Dose: 1 mg tab /12 hrs

E- Leukotriene receptor antagonists e.g. montelukast (singulair 10 mg/d).

F- Cortisone:
1- Local inhalers :(Becotid) = Beclomethazone
Dose: 800ug up to 2000ug/d (200 or 250 ug per puff)
Side Effects: oropharyngeal candidiasis, To avoid we can wash the mouth by water after use.

2- Systemic steroids: (prednisolone)
Dose: 30- 40 mg/d -->  till improvement then low dose maintenance 5 - 10 mg/d. It is better to be substituted by inhaled steroid when possible.

G- Mucolytics and expectorants do not add significantly to the treatment of bronchial asthma.
H- Anti-lgE antibody therapy can be used in patients with high levels of IgE.
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