Respiratory System, Drug Delivery Flashcards
________________ delivers the drug directly to the airways; the dose required is smaller than when given by mouth and side-effects are reduced
Inhalation
Inhaler devices include … (3)
- Pressurized metered-dose inhalers
- Breath-actuated inhalers
- Dry powder inhalers
____________ can help patients, particularly the elderly and children, use pressurized metered-dose inhalers because they remove the need to coordinate actuation with inhalation
Spacer devices
_____________ inhalers may be useful in adults and children over 5 years who are unwilling or unable to use a pressurised metered-dose inhaler.
Dry powder
Alternatively, ______________ inhalers are suitable for adults and older children provided they can use the device effectively
breath-actuated
*Consider the patient’s preference when testing alternative devices to a pressurised metered-dose inhaler; there is no evidence to dictate an order in which devices should be tested
A spacer should always be used if the patient is on a high dose of _____________
inhaled corticosteroid
In adults with mild or moderate acute asthma attacks, a pressurised metered-dose inhaler with a spacer is at least as effective as _____________
nebulisation
On changing from a pressurised metered-dose inhaler to a dry powder inhaler, patients may notice a _______________ previously associated with each actuation. Coughing may also occur
lack of sensation in the mouth and throat
The patient should be instructed carefully on the use of the inhaler. It is important to check that the inhaler continues to be used correctly because inadequate inhalation technique may be mistaken for a ______________
lack of response to the drug
The number and different types of inhalers given to a patient should be _____________
minimised
To avoid accidental aspiration of loose objects when using a pressurized metered dose inhaler, patients should be advised to carry out the following steps… (4)
- Remove mouthpiece cover fully
- Shake device
- Check both the outside and inside of the mouthpiece are clear and undamaged before inhaling dose
- Store the inhaler with the mouthpiece cover on
The spacer device reduces the _____________ of the aerosol and subsequent impaction on the oropharynx and allows more time for evaporation of the __________ so that a larger proportion of the particles can be inhaled and deposited in the lungs
velocity
propellant
Spacer devices are particularly useful for which patients? (5)
- Patients with poor inhalation technique
- Children
- Patients requiring high doses of ICS
- Nocturnal asthma
- Patients prone to candidiasis with ICS
Patients should inhale from the spacer device ________________ after actuation because the drug aerosol is very short-lived
as soon as possible
True or False: when using a spacer, patients should take a single deep breath to maximize absorption of the drug into their lungs
False; tidal breathing is as effective as single breaths
How often should spacers be cleaned?
Once a month by washing in mild detergent; should be allowed to air-dry without rinsing
Why should frequent cleaning of the spacer be avoided?
Electrostatic charge may affect drug delivery
How often should spacer devices be replaced?
Every 6-12 months
Solutions for nebulisation used in severe or life-threatening asthma attacks are administered over _________ minutes from a nebuliser, usually driven by oxygen
5–10
Patients with a severe attack of asthma should preferably have oxygen during nebulisation since beta2 agonists can increase ________________
arterial hypoxaemia
- However, the absence of supplemental oxygen should not delay treatment
A nebuliser converts a ___________ of a drug into an ___________ for inhalation.
solution
aerosol
What are the main drugs delivered by nebulizer? (6)
- Beta 2 agonist
- Ipratropium bromide
- Corticosteroid eg budesonide
- Antibiotic eg colistimethate sodium or pentamidine
- Mucolytic
- Adrenaline
What are the clinical indications of nebulizers? (5)
- Acute exacerbation of asthma or COPD (SABA or ipratropium bromide)
- Regular treatment of severe asthma or reversible airway obstruction when the patient is unable to use other devices (SABA, ipratropium bromide, or steroids)
- CF (colistimethate or mucolytics)
- Severe croup (budesonide or adrenaline)
- Prophylaxis or treatment of PJP (pentamidine)
Before prescribing a nebuliser, a home trial should preferably be undertaken to monitor response for up to ___ weeks on standard treatment and up to ___ weeks on nebulised treatment
2
2
If prescribed a nebulizer, patients must have clear instructions from a doctor, specialist nurse, physiotherapist, or pharmacist on the use of the nebuliser (including maintenance and cleaning) and on _______________
peak-flow monitoring
If prescribed a nebulizer, patients must be instructed not to ______________
have regular follow up by a doctor, specialist nurse or physiotherapist after about 1 month and annually thereafter.
treat acute attacks at home without also seeking help
If prescribed a nebulizer, patients must have regular follow up by a doctor, specialist nurse or physiotherapist after about _____________ and ______________ thereafter.
1 month
annually
The proportion of a nebuliser solution that reaches the lungs depends on the type of nebuliser and although it can be as high as _____%, it is more frequently close to ____% and sometimes below 10%
30
10
- The remaining solution is left in the nebuliser as residual volume or is deposited in the mouthpiece and tubing
The extent to which the nebulised solution is deposited in the airways or alveoli depends on the _____________, _____________, and ____________
droplet size
pattern of breath inhalation
condition of the lung
Droplets with a mass median diameter of ________ microns are deposited in the airways and are therefore appropriate for asthma, whereas a particle size of _________ microns is needed for alveolar deposition of pentamidine isetionate to combat pneumocystis infection
1–5
1–2
- The type of nebuliser is therefore chosen according to the deposition required and according to the viscosity of the solution.
Jet nebulisers are more widely used than ultrasonic nebulisers. Most jet nebulisers require an optimum gas flow rate of ________ litres/minute and in hospital can be driven by piped air or oxygen
6–8
- Domiciliary oxygen cylinders do not provide an adequate flow rate, therefore an electrical compressor is required for domiciliary use
For patients at risk of ___________, such as those with chronic obstructive pulmonary disease, oxygen can be dangerous and the nebuliser should be driven by air
hypercapnia
*If oxygen is required, it should be given simultaneously by nasal cannula
Ultrasonic nebulisers produce an aerosol by ultrasonic vibration of the drug solution and therefore do not require a gas flow; they are not suitable for the nebulisation of some drugs, such as ____________ and nebulised suspensions.
dornase alfa
Ultrasonic nebulisers produce an aerosol by ultrasonic __________ of the drug solution and therefore do not require a _________; they are not suitable for the nebulisation of some drugs, such as dornase alfa and nebulised suspensions.
vibration
gas flow
Nebulisation may be carried out using an undiluted nebuliser solution or it may require dilution beforehand. The usual diluent is ______________
sterile sodium chloride 0.9% (physiological saline)
The oral route is used when administration by inhalation is not possible. ______________ occur more frequently when a drug is given orally rather than by inhalation
Systemic side-effects
Drugs given by mouth for the treatment of asthma include _______________, _______________, and ______________
corticosteroids (though also given via inhalation)
Theophylline
LTRAs
Drugs such as _____________, _____________, and _____________ can be given by injection in severe acute and life-threatening asthma when administration by nebulisation is inadequate or inappropriate
beta2 agonists
corticosteroids
aminophylline (contains theophylline)
When used in addition to symptom-based monitoring, peak flow monitoring has not been proven to improve asthma control in either adults or children, however measurement of peak flow may be of benefit in adult patients who are ‘_____________’ and hence _________________, and for those with more severe asthma
poor perceivers
slow to detect deterioration in their asthma
When peak flow meters are used, patients must be given clear guidelines as to the ____________________
action they should take if their peak flow falls below a certain level
*Patients can also be encouraged to adjust some of their own treatment (within specified limits) according to changes in peak flow rate
