CH.8 Xanthines

Question 1

Xanthines

Answer 1

–the wake-up drugs
–stimulate the ventilatory drive
–strengthens the diaphragm
–diuresis and smooth muscle relaxation

Question 2

Use of Xanthines: Theophylline

Answer 2

–asthma
–chronic obstructive pulmonary disease (COPD)
–Apnea of prematurity in neonates

Question 3

Use of Xanthines: Asthma

Answer 3

–patients older than 5yrs
–sustained-release theophylline-maintenance therapy of mild persistent asthma

Question 4

Use of Xanthines:COPD

Answer 4

–Global initiative for Chronic obstructive Lung Disease (GOLD) states that inhaled bronchodilators are preferred
–Theophylline: recommended by GOLD as alternative to b2-agonist and anticholinergics
–not used in acute exacerbations

Question 5

Use of Xanthines: AOP

Answer 5

–use in apnea of prematurity
–first line treatment
–Theophylline most extensively used in the past, but Caffeine Citrate may be a better choice

Question 6

Advantages of Caffeine

Answer 6

–penetrates CSF better
–more potent as a stimulant of the CNS
–Dosing is simpler and give more predictable results
–wider therapeutic margin with fewer side effects

Question 7

Titrating Theophylline Doses

Answer 7

–individuals metabolize theophylline at different rates
–difficult to determine therapeutic doses

Question 8

Serum levels of theophylline

Answer 8

–less than 5: no effect
–10 to 20: therapeutic range
–greater than 20: therapeutic range
–greater than 30: nausea
–40 to 50: seizures

Question 9

Titrating Theophylline Doses: Asthma

Answer 9

–5 to 15 ug/mL

Question 10

Titrating Theophylline Doses: COPD

Answer 10

–5 to 10 ug/mL

Question 11

Rapid Theophyllization

Answer 11

–5mg/kg lean body weight oral loading dose of anhydrous theophylline
–each 0.5mg/kg=1 ug/mL serum level

Question 12

Slow titration for long-term therapy

Answer 12

–16 mg/kg/24 hr
–400 mg/24 hr

Question 13

Xanthines

Answer 13

–slow onset
–long duration of action
–Narrow therapeutic range: 5-15 mcg/ml
–side effects:Dizziness, headache, restlessness, irritability, anxiety, insomnia,
seizures, diuresis, palpitations, tachycardia, arrhythmias,
hypertension, nausea, vomiting, diarrhea, epigastric pain, and
anorexia
–inhaled theophylline is being studied to reduce side effects

Question 14

Nonbronchodilating Effect of Theophylline

Answer 14

–increase in force of respiratory muscle contractility
–increase in respiratory muscle endurance
–increase in ventilatory drive
-Cardiovascular effects: —increased cardiac output
–decreased pulmonary vascular resistance
-Anti-inflammatory effects

Question 15

Xanthines before treatment

Answer 15

–assess effectiveness of current drug therapy
–monitor flow rate with bedside peak flow meter
–Perform 4 classic vital signs
–assess serum blood levels of agent

Question 16

Xanthines during treatment

Answer 16

–assess patient’s subjective reaction to treatment
–Assess pulse oximetry
–Long term
-monitor pulmonary function studies
-education regarding peak flow meters to assess the severity of an episode of asthma
-education to emphasize that xanthines do not treat underlying inflammation or prevent progression of asthma or COPD
–assess serum blood levels of the agent