Drugs for treating asthma & COPD

Question 0

Leukotriene modifiers used to treat asthma & COPD

Answer 0

Leukotriene receptor antagonist:
Montelukast

5-LO inhibitor:
Zileuton

Question 1

Antiinflammatory drugs used for asthma & COPD

Answer 1

Steroids:
Beclomethasone
Prednisone

Histamine modulators:
Cromolyn
Omalizumab

PDE4 inhibitors:
Roflumilast

Question 2

Bronchodilators used to treat asthma & COPD

Answer 2

B2 agonist:
Albuterol
Salmeterol

Methylxanthines:
Theophylline
Aminophylline

Muscarinic receptor antagonists:
Ipratropium
Tiotropium

Question 3

Factors causing bronchoconstriction in asthma

Answer 3

M3 receptors

Mediators released from inflammatory cells:
Histamine
Leukotrienes

Iatrogenic:
Beta blockers
NSAIDS
Muscarinic receptor agonists
Anticholinesterases

Question 4

Glucocorticoids MOA

Answer 4

Glucocorticoids- suppress inflammation, decrease bronchial hyper responsiveness, most effective antiasthmatic
Used to treat mild to severe persistent asthma

Question 5

Steroids used in asthma

Answer 5

Inhalation: Beclomethasone, Fluticasone
Oral: Prednisone

Question 6

Inhaled steroids used in asthma MOA

Answer 6

Delivered to site of action-smaller doses- decrease side effects
Rapidly inactivated when absorbed

Question 7

Inhaled steroids used in asthma side effects

Answer 7

Oral candidiasis
Hoarseness
The small risk of other effects (altered bone metabolism) are outweighed by risks of not controlling severe asthma

Question 8

Oral or parental steroids used in asthma

Answer 8

Prednisone

Methylprednisolone (oral & parenteral)

Question 9

Roflumilast MOA

Answer 9

PDE4 metabolized cAMP in inflammatory cells
Roflumilast is a selective inhibition of PDE4; inhibition of PDE4 leads to increased intracellular levels of cAMP and a reduction in inflammation
Not a bronchodilator

Question 10

Roflumilast administration & elimination

Answer 10

Good oral bioavailability
Metabolized to an N-oxide which is active
Metabolized in the liver

Question 11

Roflumilast adverse effects

Answer 11

Nausea
Diarrhea
Weight loss
Headache

Question 12

Roflumilast drug interactions

Answer 12

Inhibitors of P450 enzymes will increase blood levels of drug
Inducers of P450 enzymes will decrease blood levels of drug

Question 13

Zileuton MOA

Answer 13

Blocks the enzyme 5-lipoxygenase- decreasing leukotriene synthesis
Blocks infiltration of inflammatory cells & prevents bronchoconstriction

Question 14

Zileuton adverse effects

Answer 14

Hepatitis- monitor liver function; contraindicated in patients w/ liver disease or increased liver enzymes
Upset stomach

Question 15

Zileuton drug interactions

Answer 15

Inhibits P450 so increases Warfarin, Propanolol, and Theophylline conc.

Question 16

Albuterol administration

Answer 16

Bronchodilator
Inhaled for acute relief (present in slower onset oral form)
Onset: 5-15min. 
Peak: 30min.
Duration: 6 hours

Question 17

Salmeterol administration

Answer 17

Bronchodilator
Inhaled
Preventative; not used for acute bronchospasm 
Onset: 30-50min.
Peak: 3hrs. 
Duration: 12+hrs.

Question 18

Bronchodilator MOA

Answer 18

Activation of B2 receptors- increase adenylyl cyclase activity- increase intracellular cAMP levels- bronchodilation

Question 19

Bronchodilator adverse effects

Answer 19

Anxiety, tremor, restlessness, tachycardia, & hypokalemia more common with oral & parenteral administration
Regular use can lead to drug tolerance & an increase in exacerbations; corticosteroids enhance response to B2 agonists

Question 20

Bronchodilator indications

Answer 20

Asthma & COPD
Prevention of exercise-induced asthma
Emergency treatment (status asthmaticus) together with systemic glucocorticoids (NOTE: Not Salmeterol)

Question 21

Methylxanthines

Answer 21

Theophylline
Caffeine
Theobromine

Aminophylline (theophylline ethylenediamine)- contains 85% theophylline- more soluble// rapid infusion of aminophylline causes cardiac arrest & death

Question 22

Methylxanthines MOA

Answer 22

Smooth muscle relaxation; important in bronchi
CNS stimulation- decrease drowsiness (low doses); convulsions (high doses)// increased sensitivity of medullary respiratory centers to CO2// nausea & vomiting mediated by CNS actions

Cardiovascular- tachycardia (high conc.)// decreased peripheral vascular resistance

Diuretic actions- similar to thiazides
Phosphodiesterase inhibition- increased cAMP
Adenosine receptor blockade

Question 23

Methylxanthines indications

Answer 23

Reversible airway obstruction due to asthma or other chronic lung disease

Question 24

Methylxanthines adminstration & elimination

Answer 24

Dose based on serum levels & patient response
Absorption- rapid and complete orally// sustained release preparations- decreased fluctuations between doses & increased compliance

Elimination- first order but at high conc. ZERO order// eliminated primarily by hepatic metabolism (90%)

Question 25

Factors affecting Theophylline half-life

Answer 25

Factors that increase:
Cimetidine, macrolide antibiotics, hepatic cirrhosis, premature infants, oral contraceptives

Factors that decrease:
Cigarette smoking, phenytoin, barbiturates

Question 26

Methylxanthines adverse effect

Answer 26

Mild- nausea, vomiting, headache, nervousness, insomnia
Moderate- mild symptoms with sinus tachycardia & occasional PVCs
Severe- serious arrhythmias, seizure, death

Question 27

Methylxanthines contraindications

Answer 27

Hepatic or cardiac dysfunction
Seizure disorders
Peptic ulcer disease