• Bronchodilation
• CNS stimulation
• Positive inotropic and chronotropic effects
• Diuresis
Theophylline has been claimed to reduce fatigue of diaphragmatic muscles
Uses:
Prevention and treatment of bronchospasm
Contraindications:
Uncontrolled arrhythmias
Hyperthyroidism
Administration
• Loading dose: 5 mg/kg IV, given over 30 min, followed by maintenance dose 0.1–0.8 mg/kg/h
Dilute 1 g (40 ml) aminophylline (25 mg/ml) in 460 ml glucose 5% or sodium chloride 0.9% to give a concentration of 2 mg/ml No loading dose if already on oral theophylline preparations (toxicity) Reduce maintenance dose (0.1–0.3 mg/kg/h) in the elderly and patients with congestive heart failure and liver disease Increase maintenance dose (0.8–1 mg/kg/h) in children (6 months– 16 years) and young adult smokers Monitor plasma level Therapeutic range 55–110 mmol/l or 10–20 mg/l
The injection can be administered nasogastrically (unlicensed). This may be useful as there is no liquid preparation of aminophylline or theophylline.To convert from IV to NG, keep the total daily dose the same, but divide into four equal doses.Aminophylline modified-release tablets are taken by mouth twice daily.Alternatively, if these are crushed up to go down a nasogastric tube then they will lose their slow-release characteristic and will need to be administered four times per day
keeping the total daily dose the same.
Dosage chart: ml/hr
Weight: kg
|
Dose:
mg/kg/hour
|
|||||||||
0.1
|
0.2
|
0.3
|
0.4
|
0.5
|
0.6
|
0.7
|
0.8
|
0.9
|
1
|
|
50
|
2.5
|
5
|
7.5
|
10
|
12.5
|
15
|
17.5
|
20
|
22.5
|
25
|
60
|
3
|
6
|
9
|
12
|
15
|
18
|
21
|
24
|
27
|
30
|
70
|
3.5
|
7
|
10.5
|
14
|
17.5
|
21
|
24.5
|
28
|
31.5
|
35
|
80
|
4
|
8
|
12
|
16
|
20
|
24
|
28
|
32
|
36
|
40
|
90
|
4.5
|
9
|
13.5
|
18
|
22.5
|
27
|
31.5
|
36
|
40.5
|
45
|
100
|
5
|
10
|
15
|
20
|
25
|
30
|
35
|
40
|
45
|
50
|
110
|
5.5
|
11
|
16.5
|
22
|
27.5
|
33
|
38.5
|
44
|
49.5
|
55
|
120
|
6
|
12
|
18
|
24
|
30
|
36
|
42
|
48
|
54
|
60
|
•
Elderly
•
Congestive
Heart failure
• Liver disease
|
• Usual adult maintenance
|
•
Children
•
Young adult
smokers
|
||||||||
Rapid IV administration (hypotension, arrhythmias)
Adverse effects:
Tachycardia
Arrhythmias
Convulsions
Cautions:
Subject to enzyme inducers and inhibitors
Concurrent use of erythromycin and ciprofloxacin: reduce dose
Organ failure:
Cardiac: prolonged half-life (reduce dose)
Hepatic: prolonged half-life (reduce dose)
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