Theophylline

Question 1

Signs of toxicity of Theophylline

Answer 1

Dilated pupils, agitation, hyperglycaemia, hypokalaemia, nausea, gastric ulceration, tachycardia, arrythmia (supraventricular and ventricular), convulsions

Question 2

Which antibitoic interacts with theophylinne, reducing the seizure threshold?

Answer 2

Ciprofloxacin

Question 3

How does smoking affect theophylline levels?

Answer 3

Increases the clearance of theophylline

Question 4

Risk of stopping smoking whilst on theophylline?

Answer 4

Risk of theophylline toxicity

Question 5

How do enzyme inducers affect theophylline levels?

Answer 5

Reduce theopylline levels

Question 6

How do enzyme inhibitors affect theophylline levels?

Answer 6

Increase theophylline levels

Question 7

Target plasma concentration of theophylline?

Answer 7

10-20mg/L

Question 8

When should theophylline levels be taken?

Answer 8

4-6 hours post dose

Question 9

Caution should be taken with concomittant use of which drugs due to increased risk of hypokalaemia?

Answer 9

B2-agonists, diuretics, and corticosteroids

Question 10

Whne are theophylline levels measured?

Answer 10

5 days after starting theophylline and 3 days after dose changes.

Question 11

Which patients groups have increased theophylline levels?

Answer 11

Those with hepatic impairment, heart failure, the elderly and in viral infections