Drugs used in asthma and COPD- beta-2-agonist

Question 1

how are b2 agonists split into?

Answer 1

dependants on their length of action, short and long acting

Question 2

what are the 2 types of short acting drugs?

Answer 2

salbutamol and terbutaline

Question 3

how long does it take to get maximum affect for a short acting b2 agonist?

Answer 3

30 mins for maximum and broncodilatery effects last about 4-6 hours

Question 4

how do b2 agonists work?

Answer 4

having a direct effect on b2 receptors in the airways causes the rapid broncodilation patients require when experiencing symptoms or breathlessness.

Question 5

why cant the long action b2 agonsits be used with a patient experiencing acute symptoms?

Answer 5

no rapid onset of broncodilators

Question 6

why is formoterol an anomaly?

Answer 6

because it is both a long and short acting b2 agonist with dual action

Question 7

which b2 agonists can ony be used for COPD?

Answer 7

indacaterol, olodaterol, vilanterol

Question 8

what b2 agonists are used for long action?

Answer 8

indacaterol, olodaterol, vilanterol, salmerterol, formoterol, bambuterol

Question 9

what b2 agonists are long acting that are available for asthma?

Answer 9

salmeterol and bambuterol

Question 10

what doseage form does bambuterol come in ?

Answer 10

as an oral tablet, its rarer in practise as it is a prodrug of terbutaline.

Question 11

what are some adverse effects of b2 agonists for systemic absorption?

Answer 11

• tremors
• nervous tension
• headache
• tachycardia/palpitations
• hypokalaemia

Question 12

what percentage of the drug reaches the airways using an inhaled method?

Answer 12

10-20%, rest is deposited and then swallowed

Question 13

Why may adverse effects occur?

Answer 13

When higher doses are being used

Question 14

When may a patient be given a b-anatagonist?

Answer 14

If they have CV disease

Question 15

What are some counselling points for short acting medications?

Answer 15

• reliever/rescue therapy
• carry all the time
• use before exercise
• doses per day use max salbutamol 8 times
• follow advice on hoe to take it

Question 16

What are some counselling points for long acting medication?

Answer 16

• preventer therapy

- take regularly

Question 17

What is MART therapy for asthma?

Answer 17

Uses formoterol and steroid combination, formoterol has both short and long acting components usually taken BD as preventer or used sometimes as rescue, has a rapid bronchodilater affect

Question 18

What does LABA mean?

Answer 18

Long acting b2 agonist

Question 19

What the difference between salbutamol and salmeterol with binding to active sites?

Answer 19

Salbutamol bind to the active site of the b2-adrenoreceptor but salmeterol will bind within the active site but with the exo-site

Question 20

What type of cells are b2 adrenergic receptors?

Answer 20

G-protein couple receptors

Question 21

Where does the b2 receptor bind to on the g protein?

Answer 21

B2 receptors couple with Gsa (g alpha s) sub unit

Question 22

What is the role of Gsa?

Answer 22

It dissociates from the b-gamma and goes to active adenyl cyclase which catalyses the conversion of ATP to cyclic AMP this inhibits release of calcium and encourages calcium sequestation prevents smooth muscule contraction

Question 23

When does desensitisation occur?

Answer 23

When there is continual stimulation between the agonist and receptor

Question 24

Why might we stop seeing an effect when using b2 agonists?

Answer 24

If we repeatedly stimulate with b2 agonists a tolerance can form so our body wont be seeing an effect reason why we use these in combination with other medicines