theophylline Flashcards
what is theophylline used for (indications)
Treating chronic asthma, reversible airway obstruction, severe acute asthma, chronic asthma
note brand name is: Uniphyllin Continus
how does smoking affect the dose of theophylline
The plasma-theophylline concentration is decreased in smokers. Dose adjustment may be necessary if smoking started or stopped during treatment
*note: if a smoker stops smoking, their plasma-theophylline concentration will increase. This is dangerous as theophylline has a narrow therapeutic index *
what INCREASES the plasma-theophylline concentration
- heart failure
- hepatic impairment
- viral infections
- elderly patients
what DECREASES the plasma-theophylline concentration
- smoking
- alcohol consumption.
what are the cautions for theophylline
cardiac arrhythmias, elderly, epilepsy, hypertension, peptic ulcer
what are the symptoms of theophylline overdose
vomiting, agitation, restlessness, tachycardia, hyperglycaemia, dilated pupils
more serious side effect: vomiting blood, convulsions, arrhythmias
should the dose of theophylline be adjusted during pregnancy + breastfeeding
can be taken as normal in pregnancy and
breastfeeding but can cause adverse effects (irritability in baby)
what is the ideal therapeutic range (dose) of theophylline
serum concentration is kept between 10-20mg/litre for satisfactory bronchodilation
- adverse effects can occur even in the 10-20mg/litre range. Risk of adverse effects increases further when dose over 20mg/litre
why should a prescription for theophylline modified-release specify the brand name
The rate of absorption from modified-release preparations can vary between brands. Patient needs to be maintained on a specific brand if theophylline is given modified-release
note if you receive a prescription of theophylline modified release that doesn’t specify the brand, need to call the doctor and agree on a specific brand to give the patient
