Respiratory system, drug delivery

Question 1

List three benefits of inhalation therapy compared to oral dosage forms for the treatment of asthma

Answer 1

1) Lower doses required
So:
2) Dose directly delivered to lungs
3) Less systemic side effects

Question 2

1) Elderly and children can find it difficult to use pMDI inhalers. How do spacer devices make it easier for these patients?
2) What type of inhalers can be prescribed in adults and children over 5 who are unwilling to use a pMDI?

Answer 2

1) They remove the need to co-ordinate actuation and inhalation.
2) Dry powder or alternatively breath-activated inhalers

Question 3

What might individuals notice when switching from a pMDI to a DPI? (2)

Answer 3

1) A lack of sensation in the mouth and throat previously associated with each actuation
↳check inhaler technique as this may be mistaken for a lack of response to the drug
2) Coughing

Question 4

Explain how spacers are able to deposit a larger proportion of drug particles in the lungs

Answer 4

There is more time for the evaporation of propellant, so a larger proportion of the particles can be inhaled

Question 5

List who benefits from using a spacer device? (5)

Answer 5

1) Those with poor technique
2) Children
3) High dose corticosteroids
4) Noctural asthma
5) Prone to candidiasis

Question 6

1) What type of spacer device is the most effective?

2) Are spacer devices interchangeable?

Answer 6

1) Larger spacers with a one way valve (e.g. volumatic)

2) No - patients should be advised to not to switch between spacer devices.

Question 7

Outline the two different types of techniques which can be used when breathing from a spacer

Answer 7

1) Single-dose actuation: a single slow and deep inhalation followed by a breath hold
2) Tidal breathing: If unable to inhale with a slow and deep breath, tidal breathing is equally effective. Breathe in and out of the mouthpiece five times (useful in child)
↳ in both techniques ensure there is no delay between activating the pMDI and breathing in through the spacer

Question 8

Outline the care advice that should be provided to those using spacers, including how long they should be used for before disposing

Answer 8

1) Clean once a month by washing in mild detergent and then allow to air dry without rinsing. More frequent cleaning should be avoided as electrostatic charge may affect drug delivery
2) Replace every 6-12 months

Question 9

Nebulisers should be used during a severe acute asthma attack. Explain why nebulisers are often driven by oxygen in patients experiencing a severe attack of asthma

Answer 9

Because Beta2 agonists can increase arterial hypoxaemia

Question 10

What conditions are nebulisers indicated for use in? (5)

Answer 10

1) Acute exacerbation of asthma or COPD
2) Regularly in patients with severe asthma, when patient is unable to use other inhalation devices
3) Antibiotic or mucolytic to patients with cystic fibrosis
4) Child with severe croup
5) Those who remain breathless despite correctly using optimal therapy

Question 11

When should the use of nebulisers in chronic persistent asthma and COPD only be considered?

Answer 11

1) After review of diagnosis
2) After review of therapy and patients ability to use hand held devices
3) After increased dose of inhaled therapy from hand-held inhalers has been tried for 2 weeks
4) In patients who remain breathless despite correctly using optimal therapy

Question 12

What should be undertaken before prescribing a nebuliser?

Answer 12

A home trial for up to 2 weeks on standard treatment and then up to 2 weeks on nebulised treatment
↳( Ensure patient monitors peak-flow & has a follow up after 1 month and then annually)

Question 13

The extent to which a nebulised solution is deposited into the lungs is dependent on which criteria?

Answer 13

1) Pattern of breath inhalation
2) Condition of lungs
3) Droplet size:
↳1-5 microns: Deposited in the airways, appropriate for asthma
↳1-2 microns: Needed for alveolar deposition of pentamidine isetionate for pneumocystis infection

Question 14

The type of nebuliser chosen depends on the deposition required and the viscosity of the solution. List the two types of nebulisers

Answer 14

1) Jet nebuliser- driven by oxygen or air

2) Ultrasonic- vibrations (does not require gas flow)

Question 15

State the usual diluent used in nebulisation

Answer 15

Sodium chloride 0.9%

Question 16

Peak flow monitoring has NOT been proven to improve asthma symptoms in adults or children. Outline which patients benefit from peak flow monitoring

Answer 16

1) Adult patients who are “poor perceivers” and therefore slow to detect deterioration in their asthma
2) Those with severe asthma

Question 17

1) When selecting inhaler devices for children under 5 years with chronic asthma, what should govern the choice of device?
2) What type of device is recommended in this group for corticosteroid and bronchodialator therapy?

Answer 17

1) The childs needs and compliance. Only then should cost be considered
2) Corticosteroid and bronchodialator therapy should be delivered by pMDI and spacer device
↳ If not effective, nebulised therapy or DPI can be considered if children over 3 years

Question 18

1) When selecting inhaler devices for those aged between 5-15 years with chronic asthma, what should govern the choice of device?
2) What type of device is recommended in this group for corticosteroid and bronchodilator therapy?

Answer 18

1) Child’s needs, ability to develop and maintain effective technique, likelihood of compliance
2) Corticosteroid: pMDI inhaler and spacer device
↳ Bronchodilator: wider range of devices can be considered

Question 19

How often should the suitability of an inhaler device be reviewed?

Answer 19

At least annually