This document provides a comprehensive overview of beta-2 agonists, a class of bronchodilator medications primarily used to treat asthma and COPD. It outlines their mechanism of action, categorization into short-acting and long-acting formulations, their dosages, potential drug interactions, and adverse effects. Additionally, it emphasizes the importance of using long-acting beta-2 agonists in conjunction with inhaled steroids for long-term asthma control.

1. Presented by,
Vishnu.R.Nair,
5th year Pharm.D,
Date of presentation: 09.02.2018

2. GENERAL INTRODUCTION

3. - BETA-2 AGONISTS ( Also known as Beta-2 adrenergic receptor agonists) 
represent drugs that come under the class of “BRONCHODILATORS”
- Drugs  relax & enlarge (dilate) airways in lungs  makes breathing easier
- Primarily used to treat asthma & other pulmonary disorders like COPD
- Classified into:
1. SABA(Short-Acting Beta-2 Agonists)
2. LABA(Long-Acting Beta-2-Agonists).

4. MECHANISM OF ACTION

5. - Beta-2-agonists  bind to beta-2-receptors (coupled with stimulatory
G-protein of adenyl cyclase enzyme) of bronchial smooth muscle of
lung  enzyme increases concentration of Cyclic-AMP levels in lung
 leads to reduction of Ca++ concentration within cells  activation
of protein kinase A  leads to increased membrane potassium
conductance  causes smooth muscle relaxation & bronchodilation.
- Activation of beta-adrenergic receptors  causes relaxation of
smooth muscle in the lung  causes dilation & opening of airways.

6. ADVERSE EFFECTS

7.  Adverse effects include:
1. Headache
2. Anxiety
3. Nausea
4. Muscle tremors
5. Nervousness
6. Increased / irregular heartbeats(Palpitations).

8. SHORT-ACTING BETA-2-
AGONISTS(SABA)

9.  Also known as “Quick-acting”, “Reliever” / “Rescue” medications
 These drugs  relieve acute asthma symptoms/ attacks very quickly, by opening
the airways
 Rescue medications are considered best for treating sudden asthma symptoms
 Action of inhaled bronchodilators  starts within minutes(post-inhalation) 
lasts for 2-4 hours
 SABA  also used before exercise, to prevent exercise-induced asthma.

10.  Include:
1. Salbutamol(albuterol)
2. Levosalbutamol(levalbuterol)
3. Metaproterenol
4. Pirbuterol
5. Isoproterenol(Isoprenaline)
6. Terbutaline sulphate.

11.  Short-acting, selective beta-2 receptor agonist, used in the treatment of Asthma
& COPD
 DRUG-INTERACTIONS:
a. Salbutamol + Saquinavir  Both increase toxicity of each other by
Pharmacodynamic synergism  high risk of hypokalemia, QT prolongation &
cardiac arrhythmias
b. Salbutamol + arformoterol  Pharmacodynamic synergism  insomnia may
occur.
• CONTRAINDICATIONS:
a. Hypersensitivity to salbutamol
b. Severe hypersensitivity to milk proteins

12.  DOSE:
a. FOR BRONCHOSPASM:
- As nebulizer solution : 2.5 mg BID/TID PRN; 1.25-5 mg Q4-8 hr PRN, for quick
relief
- As aerosol MDI : 180 mcg(2 puffs), inhaled PO Q4-6 hr(Not to exceed 12
inhalations/24 hour)
- As powder MDI: 180 mcg (2 puffs) inhaled PO q4-6hr; not to exceed 12
inhalations/24 hr.
- As tablet and syrup: 2-4 mg PO q6-8hr; not to exceed 32 mg/day

13.  Levosalbutamol  has similar therapeutic effects as that of salbutamol in acute
exacerbation of asthma  but has no side-effects, such as tachycardia &
hypokalemia.
 DRUG INTERACTION:
a. Levosalbutamol + Arformoterol  reduced serum potassium & sedation.
• DOSE:
a. FOR BRONCHOSPASM:
- Nebulizer solution: 0.63-1.25 mg 3 times daily q6-8hr
- Aerosol: 90 mcg (2 actuations of metered-dose inhaler) q4-6hr
b. FOR ASTHMA EXACERBATION:
- As nebulizer solution: 1.25-2.5 mg q20min for 3 doses, then 1.25-5 mg q1-4hr PRN
 Aerosol: 180-360 mcg (4-8 actuations of metered-dose inhaler) q20min for ≤4 hr, then q1-4hr PRN

14.  Synthetic amine
 Structurally & pharmacologically similar to ISOPROTERENOL
 Used as bronchodilator in treatment of asthma
 DRUG INTERACTIONS:
a. METAPROTERENOL + SALBUTAMOL  Increased adrenergic effects 
chances of raised blood pressure & HR
• DOSE:
a. FOR REVERSIBLE BRONCHOSPASM:
- 20 mg PO three/four times daily

15.  Beta-agonist bronchodilator, used in asthma treatment for reversal of acute
bronchospasm, & also as maintenance medication to prevent future attacks.
 DOSE:
For Asthma Maintenance :
- 1-2 actuations q4-6hr PRN; not to exceed 12 actuations/day

16.  Non-selective beta-adrenergic receptor agonist
 Also known as ISOPRENALINE
 Used in management of shock, heart block/cardiac arrest & bronchospasm
 DOSE:
a. For Bronchospasm during anesthesia:
 0.01-0.02 mg IV, repeat PRN

17.  Resorcinol , is a SABA, used as bronchodilator
 DOSE:
a. For Bronchospasm:
i. As PO:
 Initiate at 2.5 mg three/four times daily PO
 Maintenance: 5 mg three times daily PO q6hr while patient is awake; reduce dose to 2.5 mg q6hr
 Not to exceed 15 mg/day
ii. As s.c:
 0.25 mg q15-30min x 3 doses PRN in lateral deltoid
 Not to exceed 0.5 mg/4 hr

18. LONG-ACTING BETA-2
AGONISTS(LABA)

19. - The long-acting bronchodilators are used to provide control ( NOT QUICK
RELIEF ) of asthma.
- They should only be used in conjunction with INHALED STEROIDS for long-
term control of asthma symptoms.
- Used twice a day.
- Long-acting beta-agonist bronchodilators increase the risk of death from asthma
and should only be used as additional treatment for people who are also using an
inhaled steroid.

20.  Examples of LABA include:
1. Formoterol
2. Arformoterol
3. Salmeterol
4. Indacaterol
5. Vilanterol
6. Olodaterol .

21.  Inhaled LABA, used in the management of asthma, COPD & exercise-induced
bronchospasm.
 DRUG INTERACTION:
a. Formoterol + CPZ  Prolongation of QTc interval
b. Formoterol + Amiodarone/Dronedarone  Prolongation of QTc interval
• DOSE:
a. 20 mcg, inhaled via nebulizer, q12hr(For long-term maintenance treatment of
COPD)

22.  R-enantiomer of formoterol
 Potent, highly specific, nebulized, LABA
 Approved by US-FDA for long-term maintenance treatment of
bronchoconstriction in patients with COPD
 DRUG INTERACTION:
a. Arformoterol + Linezolid  increased effects of former, by pharmacodynamic
synergism  high risk of acute hypertensive episode
• DOSE:
- 15 mcg inhaled via nebulization twice daily (AM & PM)
- Not to exceed 30 mcg/day

23.  Inhalational LABA
 Can be used in combination with FLUTICASONE
 DRUG INTERACTION:
a. Salmeterol + indinavir  increased levels of salmeterol  increased toxicity.
 DOSES:
a. For asthma prevention & maintenance:
- 1 inhalation (50 mcg) twice daily; not to exceed twice daily administration
b. For COPD maintenance:
- 1 inhalation (50 mcg) twice daily; not to exceed twice daily administration.

24. - LABA, used in COPD as bronchodilator
- Can also be used in combination with GLYCOPYRROLATE(Utibron Neohaler)
- ADRs:
a. Post-inhalational cough(>10%)
b. Nasopharyngitis (6.5%)
c. Headache (5.1%).
- DRUG INTERACTION:
a. Indacaterol + Umeclidinium bromide / Vilanterol  increased toxicity of each
other  increased HR & B.P

25.  DOSE:
IN COPD:
- Long-acting beta2-agonist indicated for long-term, once-daily maintenance
bronchodilator treatment of airflow obstruction in patients with chronic
obstructive pulmonary disease (COPD), including chronic bronchitis and/or
emphysema
- 75 mcg inhaled orally qDay; not to exceed once daily
- Limitations of use:
1. Not indicated for acute deteriorations of COPD
1. Not indicated for asthma

26.  Selective LABA, with inherent 24-hour activity for once-daily asthma treatment
 Used in combination as:
a. Vilanterol + Fluticasone propionate
b. Vilanterol + Fluticasone + Umeclidinium bromide
• ADRs:
a. Nasopharyngitis (9%)
b. URTI (7%)
c. Anticholinergic effects (with umeclidinium)
d. Headache (7%)
e. Oropharyngeal candidiasis(6%)

27.  DOSE:
a. With FLUTICASONE:
- For COPD: 25 mcg/100 mcg (1 actuation), inhaled PO qDay
- For asthma : (25 mcg/100 mcg or 25 mcg/200 mcg per actuation) once daily via
oral inhalation
b. WITH UMECLIDINIUM BROMIDE:
- For COPD: 62.5 mcg/25 mcg (1 actuation), inhaled PO qDay
c. VILANTEROL + FLUTICASONE + UMECLIDINIUM COMBINATION:
- For COPD: 1 inhalation PO qDay(100 mcg/62.5 mcg/25 mcg).

28.  LABA, that activates specific BETA-2-ADRENERGIC receptors on the surface of
smooth muscle cells, increasing the levels of intracellular CYCLIC-AMP, thereby
causing smooth muscle relaxation.
 Has been reported to cause nasopharyngitis more compared to other LABAs
 DRUG INTERACTIONS:
a. Olodaterol + Amitriptyline  prolongation of QTc interval  increased risk of
ventricular arrhythmias
• Indicated for maintenance bronchodilator treatment in patients with
COPD(including chronic bronchitis &/ emphysema), with airflow obstruction
• DOSE:
- 5 mcg(2 actuations), inhaled PO, qDay, at the same time of the day
- Not to exceed 2 inhalations every 24 hours.

29. THANK YOU!!!