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Why Use Xanthines?. Used as bronchodilators for asthma and COPD patientsNot as widely used in the 90's as has been the case in the pastNow considered to be second or third-line drugs in treatment of asthma
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1. Pharmacology - Xanthines By Jim Clarke
2. Why Use Xanthines? Used as bronchodilators for asthma and COPD patients
Not as widely used in the 90’s as has been the case in the past
Now considered to be second or third-line drugs in treatment of asthma & COPD
3. Types of Xanthines Caffeine - limited bronchodilating effect
Theobromine - found in cocoa
Theophylline preparations
has been widely used as a bronchodilator
years ago used as a dieuretic
4. Physiological Effects of Xanthines Central Nervous System stimulant
Stimulates cardiac muscle
Increases diuresis
Relaxes bronchial, vascular and uterine smooth muslce
Peripheral & coronary artery vasodilation
Cerebral vasoconstriction
5. How Theophylline Bronchodilates Currently there are 3 theories;
Inhibition of Phosphodiestarase
Antagonism of Adenosine
Increases production of catecholamines
Theophylline preparations also may increase breathing muscle strength
6. How Theophylline is Given I.V. Preparations -
Aminophylline
P.O. Preparations
Bronkodyl
Elixophylline
Slo-Phylline
Theo-Dur
Choledyl
7. Side Effects Nausea, vomiting, anorexia, diarrhea
Cardiac arrhythmias, hypotension
Tachypnea
Headache, restlessness, insomnia, anxiety
Seizures
8. Monitoring Blood Levels Theophylline levels should be between 5 and 20 mcg/ml
Levels > 30 mcg/ml can cause cardiac arrhythmias
Levels > 40 mcg/ml can cause seizures
9. Agents That Effect Theophylline Blood Levels Decrease blood levels
Beta agonists
Cigarette smoking
Increase blood levels
Cirrhossis & hepatitis
Corticosteroids
Beta-blockers
10. Clinical Uses Not recommended as a first-line drug in asthma treatment
Only recommended in asthma when the more typical agents have not worked
ATS guidelines DO recommend it’s use in treatment of exacerbations of COPD
Can cause severe gastric upset
11. End of Presentation