xanthines Flashcards
1
Q
example
A
theophylline
2
Q
main indication
A
add on in uncontrolled moderate/severe asthma
used in acute severe asthma presentation
3
Q
mechanism of action
A
- inhibit mediator release from mast cells, increase mucus clearance, increase diaphragmatic contractility and reduce fatigue
- non selective phosphodiesterase inhibitor - prevent inactivation of cAMP and cGMP by phosphodiesterase
4
Q
what are cAMP and cGMP
A
secondary messengers that relax smooth muscle and may be anti inflammatory
5
Q
contraindications and cautions
A
problematic due to multiple drug interactions involving CYP450s
6
Q
adverse effects
A
- very narrow therapeutic window
- side effects of supra therapeutic concentrations include dysrhythmia, seizures and hypotension
- side effects at therapeutic concentrations - nausea, vomiting, abdominal discomfort and headache
7
Q
administration
A
oral (theophylline) - for asthma maintenance
IV (aminophylline) for acute asthma attacks
