Chapter 8 Xanthines Flashcards
Name two methylxanthines
theophylline and aminophylline
What are the clinical indications for using methylxanthines?
management of COPD and asthma;
apnea in prematurity
Would methylxanthines be your first choice of bronchodilator?
No. It is a 2nd or 3rd line agent. In asthma, it is relegated to 3rd line use (after all else)
What effect do methylxanthines have?
they increase ventilatory drive and strengthen the diaphragm which may improve flow
T/F methylxanthines have comparable bronchodilation as beta agents.
false
Theophylline sustained release is used as a long term controller to treat what?
stage 2 asthma patients and in stage 2 or moderate stage 3 COPD
T/F Theophylline is preferred to low dose inhaled steroids
false. low-dose inhaled steroids or cromolyn sodium is preferred
What is the route of administration of theophylline in COPD exacerbations?
IV- only when beta agonists and anticholinergics are inadequate
What are the contraindications for using theophylinne
do not use in patients with peptic ulcer or acute gastric diagnosis
What are the routes of admission for xanthine agents?
sustained release tablets; IV; rectal- CAN’T BE AEROSOLIZED
Where can naturally occurring xanthine be found?
coffee and cola
tea leaves- caffeine and theophylline
cocoa- caffeine and theobromide
Synthetic xanthine is packaged how?
aminophylline (theophylline salt)- mix of 79% theophylline and 21% suspension agent
what is the mode of action of xanthines?
inhibit phosphodiesterase
What are some general pharmacologic properties of xanthines?
CNS stimulation; Cardiac stimulation
diuresis; bronchial, uterine and vascular smooth muscle relaxation; peripheral and coronary vasodilation; cerebral vasoconstriction
What is the therapeutic dosing range of theophylline?
10-20 ug/ml
What is the dosage for COPD patients?
10-12 ug/ml
What is the dosage for asthma patients?
5-15 ug/ml
The therapeutic range of theophylline is best described as what?
narrow- it has many toxic side effects
What are the CNS side effects
headache, anxiety, restlessness, insomnia, tremor, convulsions
What are the gastrointestinal effects?
nausea, vomiting, loss of appetite, abdominal pain, diarrhea, hematemesis, GERD
What are respiratory side effects?
tachypnea
What are cardiovascular side effects?
palpitations, superventricular tachycardia, ventricular arrhythmias, hypotension
What are renal system effects?
diuresis
Theophylline is metabolized in the ___ and eliminated by the ___
liver, kidneys
