Theophylines

Question 1

What are the theophylline’s

Answer 1

Aminophyllines
Theophylline

Question 2

What are indications for theophylline’s

Answer 2

Maintenance therapy in asthma and Cop( rarely)

Question 3

(PRECAUTION) What are the factors for increased Theophylline Clearance ( increase dose )

Answer 3

• SMOKING-increases theophylline clearance, larger dose if theophylline may be needed
  Heart failure/pulmonary oedema/sever hypoxia- reduce clearance of theophylline-smaller dose needed
• THYROID DYSFUNCTION-HYPERthyroidism increases clearance , HYPOthyroidism decreases clearance

Question 4

THEOPHYLINE PRECAUTIONS ( P/B , elderly, hepatic, Diseases)

Answer 4

Pregnancy- monitor levels
Breastfeeding- inhaled bronchodilator’s preferred ie fometerol (LABA), irritability has been reported in infants. KEEP dose LOW as possible
ELDERLY- clearance reduces with age - dose reduction required

• GORD- may worsen- they increase gastric secretion and relax gastro oesophageal sphincter
• ARRYTHMIA- may be exacerbated.
• EPILEPSY- reduce seizure threshold
• Treatment with beta2 agonist( SABA/LABA)- increase risk of hypokalemia- monitor potassium concentrations in sever asthma

Question 5

What are the symptoms of theophyine toxicity ( adverse effects)

Answer 5

Common- nausea,vomiting, diarrhoea, acid reflux, headache, insomnia, tremor, irritability
Rare- seizures, arrhythmia, tachycardia

Question 6

(PRECAUTIONS)What are the risk factors for decreased theophyline clearance (TOXICITY)

Answer 6

VIRAL INFECTIONS- reduce clearance of theophylline’s - can cause toxicity- reduce dose of theophylline.
Elderly- clearance reduces with age
Hepatic failure - reduces clearance- may need to reduce dose

Question 7

HOW do you start dosing and monitoring for THEOPHYLINE

Answer 7

SR- products preferred
Initially- 300mg daily for 3 days, if tolerated can increase to 450mg daily 3 days then 600mg d (max 900mg d)
Monitor plasma concentrations
- start of treatment.
- After 3 days at highest concentration
- if dose is altered.
- pt stops smoking
- Pt has a fever
Therapeutic range 10-20mg/L

Question 8

What are the practice points with theophylline and counselling

Answer 8

Take with food as it can cause an upset stomach
Do not crush and swallow whole