Ch 8 Xanthines Flashcards
What are the first and second line uses of xanthines?
1st line - Apnea of prematurity
2nd line - asthma and COPD
Theophylline vs caffeine in treating apnea of prematurity?
Both are first line treatments for the disease. Theophylline is most extensively used.However, caffeine citrate is safer and has a higher therapeutic index.
What are the major xanthines?
Theophylline
Theobromine (won’t talk about)
Caffeine
What are some advantages to using caffeine?
It has greater CNS stimulation (ventilatory stimulation in neonates) and skeletal muscle stimulation
What are some effects of caffeine on humans?
CNS and cardiac muscle stimulation
Diuresis
Bronchial, uterine, and vascular smooth muscle relaxation
Peripheral and coronary vasodilation
Cerebral vasoconstriction (for headache relief)
What are the two types of theophylline?
Anhydrous theophylline = 100%
Salts of theophylline = not pure by weight
What is the therapeutic dosage range for theophylline?
10 - 20 ug/mL
Greater than 20 can cause nausea
Greater than 30 can cause arrhythmias
Greater than 40 can cause seizures
Theophylline asthma dosage range?
5 - 15 ug/mL
Theophylline COPD dosage range?
5 - 10 ug/mL
What are the times for serum drug levels? (Immediate vs. sustained release)
Immediate = 1-2 hours after administration Sustained = 5-9 hours after administration
Common side effects of theophylline?
gastric upset
headache
anxiety
diuresis
Conditions which could increase theophylline levels?
viral hepatitis CHF B blockers corticosteroids influenza virus vaccine estrogen renal failure pneumonia
Conditions which could decrease theophylline levels?
smoking! X-(
barbituates
B agonists
Rifampin
What are some nonbronchodilating effects of theophylline?
Increase force of respiratory muscle contractility
Increase in respiratory muscle endurance
Increase in ventilatory drive
Increased CO
Decreased PVR
Along with some anti inflammatory effects…
