Theophylline

Question 1

What is the therapeutic range for Theophylline?

Answer 1

10 to 20mg/L (55 to 110micromol/L)

Loading doses may be required, although a plasma theophylline concentration of 5 to 15mg/L may still be effective.

Question 2

What are the major routes of elimination for Theophylline?

Answer 2

Hepatic metabolism

Monitoring includes serum potassium and plasma theophylline concentration.

Question 3

List some warning signs that require action for Theophylline patients.

Answer 3

• Symptoms of uncontrolled asthma (cough, wheeze, tight chest)
• Frequent courses of antibiotics and/or oral corticosteroids
• Toxicity symptoms (e.g., vomiting, agitation, restlessness, dilated pupils, sinus tachycardia, hyperglycaemia, severe hypokalaemia, haematemesis, convulsions, cardiac arrhythmias)

Advise patients to report immediately to a doctor if any warning signs occur.

Question 4

True or False: Patients should inform their GP before stopping or starting smoking while on Theophylline.

Answer 4

True

Inform the patient of potential interactions with Theophylline and the need to check with a pharmacist or doctor before taking any new medication.

Question 5

What should patients maintain regarding their Theophylline medication?

Answer 5

The same brand of medicine

The rate of absorption from modified-release preparations can vary between brands.

Question 6

What risk may result from beta-agonist therapy in Theophylline patients?

Answer 6

Potentially serious hypokalaemia

Caution is required in severe asthma, as this effect may be potentiated by concomitant use of Theophylline, corticosteroids, and diuretics.

Question 7

Which medications can increase plasma concentrations of Theophylline?

Answer 7

• Diltiazem
• Cimetidine
• Ciprofloxacin
• Erythromycin
• Oestrogens
• Fluvoxamine
• Verapamil

Possible increased risk of convulsions when Theophylline is given with quinolones.

Question 8

Which medications can reduce plasma concentrations of Theophylline?

Answer 8

• Carbamazepine
• Primidone
• Phenobarbital
• Phenytoin
• Ritonavir

Monitoring plasma potassium is essential in severe asthma.

Question 9

Fill in the blank: Patients on Theophylline should check with a pharmacist or doctor before taking any new _______.

Answer 9

medication

This includes OTC, prescribed, or herbal medicines.