High Risk Meds - Resp

Question 1

Theophylline Indications and Dose- what is it used for? What’s the dose for severe acute asthma?? It’s adjusted to response to what and how often?

Answer 1

Indications and Dose
➢ Chronic Asthma
➢ Reversible airways
obstruction
➢ Severe acute asthma
➢ 200 mg every 12 hours,
adjusted according to response to 400 mg every 12 hours.

Question 2

Side effects(8)

Answer 2

Side effects
➢ Anxiety
➢ Arrhythmias and palpitations ➢ GI discomfort
➢ Headache
➢ Hyperuricaemia
➢ Nausea and vomiting
➢ Seizures and tremors
➢ Skin reactions
➢ Urinary disorders

Question 3

Cautions for theophylline - which diseases would we avoid theophylline in???? Which group of patients??? Because it can do what to plasma conc?? (8)

Answer 3

Cautions
➢ Cardiac arrhythmias or other cardiac disease
➢ Elderly (↑ plasma-theophylline concentration)
➢ Epilepsy
➢ Fever
➢ Hypertension
➢ Peptic ulcer
➢ Risk of hypokalaemia
➢ Thyroid disorder

Question 4

Pharmacokinetics of theophylline and MR brands - theophylline is metabolised by the…
What’s the issue with MR preps and branding??

Answer 4

Pharmacokinetics
➢ Metabolised in the liver
➢ Rate of absorption from M/R prep
can vary between brands

Question 5

Overdose + management of theophylline overdose - what are the symptoms of an overdose??? What is the antidote? What do we focus on when treating an overdose?? What can no asthmatics administer that may help?

Answer 5

Overdose
Symptoms
➢ Vomiting (which may be severe and intractable), agitation, restlessness, dilated pupils, sinus tachycardia, and hyperglycaemia.
➢ More serious effects are haematemesis, convulsions, and supraventricular and ventricular arrhythmias. Severe hypokalaemia may develop rapidly.
Management
➢ Activated Charcoal
➢ Supportive management, focusing on treating vomiting,
convulsions, and hypokalaemia.
➢ Non-asthmatics can administer IV short-acting beta-blocker to
reverse severe tachycardia, hypokalaemia, and hyperglycaemia.

Question 6

Monitoring Requirements
- what is the desired therapeutic concentration?
- how often is it measured for oral dose?
- how often should a blood sample be taken? For modified preps in terms of hours?

Answer 6

Monitoring Requirements
➢ Therapeutic range 10–20 mg/litre (55– 110 micromol/litre)
➢ Measured 5 days after starting oral treatment and at least 3 days after any dose adjustment.
➢ Blood sample should usually be taken 4–6 hours after an oral dose of a M/R preparation.

Question 7

Interactions(8 groups)( fluvoxamine is the one I keep forgetting)
- what is the relation with hypokalemaia?
- enzymes inhibitors can do what to plasma conc?
- enzyme inducers can do what to conc?
- what about smoking?
- what about fluvoxamine?
- what about lithium/?

Answer 7

1)Hypokalaemia
•Beta2 agonists, Corticosteroids and Diuretics
Enzyme inhibitors (↑ plasma theophylline concentration)
•
Enzyme inducers (↓ plasma theophylline concentration)
•
Starts or stops smoking
•Dose adjustment may be needed because tobacco can lower the plasma levels of theophylline
Raise the plasma level of theophylline
•Fluvoxamine (long half life)
Excretion of lithium may be potentiated
•Lithium

Question 8

Plasma theophylline concentration is ↑
- in what 3 conditions or events / which 1 group of patients?

Answer 8

o Heartfailure
o Hepatic impairment o Viralinfections
o Elderly

Question 9

Plasma-theophylline concentration is ↓

Answer 9

o Smokers
o Alcoholconsumption o Fever