Drugs & Drug Delivery In Asthma & COPD

Question 1

Function of Theophylline/Aminophylline

Answer 1

Phosphodiesterase inhibitor

Bronchodilation

May have additive effects when used in conjunction w/ small doses of Beta₂-agonists

Clearance is increased by smoking + reduced in heart failure, liver disease + COPD

Drug interactions

Monitoring

Brands - different brands have different rate of absorptions

Question 2

Function of a leukotriene receptor antagonist

Answer 2

e.g. Montelukast

Block leukotrienes effects

Question 3

Function of long-acting Beta2-agonists (LABA)

Answer 3

e.g. Salmeterol, formoterol

Same mode of action + adverse effects of SABA Works within 15-40 min

Effects last > 12 hours

Question 4

Why are inhalers not used correctly?

Answer 4

Inhaler design

Individual patient factors

Lack of education - does HCP know how to use device correctly?

Question 5

Disadvantages of dry powder inhaler

Answer 5

Work poorly if inhalation is not powerful enough

Need to prime dose each time

Most are moisture sensitive

Question 6

Why is inhaler design a problem

Answer 6

patient cannot use device

patient may have different device

Question 7

Advantage of pMDI

Answer 7

Compact

Portable

Multidose delivery

Suitable for emergency

Question 8

When can inhaler devices be prescribed to the patient

Answer 8

Only after patients have received training in the use of the device and have demonstrated satisfactory technique

Generic prescribing avoided = lead to people with asthma being given an unfamiliar inhaler device which they are not able to use properly

Question 9

Factors that increase levels of Aminophylline

Answer 9

Cimetidine

Ciprofloxacin

Macrolides

Oral contraceptive

Viral infection

Heart failure

Cirrhosis

Elderly

Question 10

What is Haleraid?

Answer 10

Improves grip - patients with dexterity problems

Helps with compliance

Requires coordination

Question 11

Types of inhalers

Answer 11

Pressurised metered dose inhaler (pMDI)

Dry powder inhaler (DPI)

Question 12

Adverse effects of Corticosteroids

Answer 12

Oropharyngeal candidiasis

Adrenal suppression

Osteoporosis

Growth suppression

Pneumonia

Glaucoma

Question 13

Benefits of Aminophylline

Answer 13

Failure to respond to other treatments

Not effective in exacerbations if COPD

Individual patients w/ near fatal or life-threatening asthma + a poor response to initial therapy may gain additional benefit

Question 14

Function of long-acting muscarinic antagonist (LAMA)

Answer 14

e.g. Tiotropium, Aclidinium

Patients who remain breathless despite short-acting bronchodilators

Works within 1-2 hrs

Lasts for 24 hrs

Question 15

Adverse effects of LTRA

Answer 15

Churg-Strauss syndrome

Hepatic disorders

Question 16

Adverse effects of Aminophylline

Answer 16

Tachycardia

Palpitations

Nausea + vomiting

Headache

Insomnia

Arrhythmias

Same for theophylline

Drug interactions + narrow therapeutic window

Question 17

Disadvantages of pMDI

Answer 17

Requires co-ordination

High oropharyngeal drug deposition

Question 18

Function of Magnesium sulphate

Answer 18

Relaxes smooth muscle

Weak bronchodilator

Prescribe - 1.2-2 grams by IV infusion over 20 min

Aimed for patients who have acute severe but poor response to inhaled bronchodilators or life threatening asthma

Question 19

Side effects of LAMA

Answer 19

Same as SAMA

Dry mouth

Blurred vision

Constipation

Nausea

Urinary retention

Tachycardia

Question 20

Disadvantages of breath-actuated MDI

Answer 20

Require sufficient inspiratory flow to trigger device

Question 21

Function of short-acting Beta2-agonists (SABA)

Answer 21

e.g. Salbutamol, Terbutaline

Relax smooth muscle + bronchodilate

Reduce breathlessness

Reliever/rescue medicines

Work quickly - effective withn 5 min + last for 4-6 hours

Do not control/prevent inflammation

Question 22

Factors that decrease level of Aminophylline

Answer 22

Carbamazepine

Phenytoin

Rifampicin

St John’s Wort

Smoking

Chronic alcoholism

Question 23

Advantages of Dry powder DPI

Answer 23

Breath actuated

Less coordination required

Compact

Portable

Higher lung deposition than pMDI

Question 24

Side effects of SAMA

Answer 24

Dry mouth

Blurred vision

Constipation

Nausea

Urinary retention

Tachycardia

Question 25

Combination products

Answer 25

Combining inhaled steroid + LABA E.g. Seretide® Fluticasone and salmeterol

Question 26

Function of short-acting muscarinic antagonist (SAMA)

Answer 26

e.g. Ipratropium

Antagonise acetylcholine-mediated contribution to bronchospasm

Reliever = smooth muscle relaxation

Works within 30-40 min

Last for 3-6 hrs

Question 27

Advantage of Breath-actuated MDI

Answer 27

Help to overcome coordination problems

Do not require coordination of device and inhalation

Question 28

Function of Corticosteroids

Answer 28

e. g. Beclometasone, Budesonide, Fluticasone (inhaled)
e. g. Prednisolone (oral)

Reduce airway inflammation

Regular use reduces exacerbations

Question 29

Discuss Nebulisers

Answer 29

A nebuliser converts a solution of a drug into a fine spray. You then breathe in the spray.

For patients with disabling breathlessness despite maximum therapy w/ inhalers

Suitable for severe acute asthma

Used in hospital

Low efficiency

Susceptible to microbiological contamination

Glaucoma risk w/ nebulised ipratropium

Question 30

Why is indivdual patient factors a problem

Answer 30

Pulmonary function

Ability to remember correct method

Question 31

What are Spacers?

Answer 31

Remove the need for coordination

Improve drug delivery

Reduce risk of oral infection from inhaled steroids

• steroid doesn’t deposit in mouth

Suitable for managing mild/moderate acute asthma/COPD

In children, pMDI + spacer are preferred for delivery of Beta₂-agonists + inhaled corticosteroids

• face mask required until child can breathe using the spacer mouthpiece