THEOPHYLLINE

Question 1

drug class

Answer 1

theophyllines

Question 2

How does it work? (2)

Answer 2

1. competitive non-selective phosphodiesterase inhibitor

2. non-selective adenosine receptor antagonist

Question 3

How does theophylline work as a competitive non-selective phosphodiesterase inhibitor and what is the overall effect? (4,2)

Answer 3

1. it raises intracellular cAMP
2. this activates PKA
3. inhibits TNF-alpha
4. inhibits leukotriene synthesis

OVERALL EFFECT

• reduces inflammation
• reduces innate immunity

Question 4

How does theophylline work as a non-selective adenosine receptor antagonist and what is it’s overall effect? (3)

Answer 4

1. antagonises A receptors - hence cardiac effects
2. inhibits TGF-betamediated conversion of pulmonary fibroblasts into myofibroblasts in COPD
3. suppressed collagen mRNA in asthma

• may reverse steroid insensitivity in asthma and copd

Question 5

Indications (2)

Answer 5

1. COPD

2. Asthma

Question 6

Contraindications (13)

Answer 6

DRUGS

• allergy to aminophylline or xanthines
• dipyradamole IV
• febuxostat
• halothane

BABY
- pregnant

HEART
- heart problems

SYSTEMIC SIGNS

• shock
• fever

STOMACH
- ulcer

LUNGS

• CF
• fluid in lungs
• severe infection
• smoking

Question 7

Side effects (3)

Answer 7

1. changes in behaviour - restlessness, irritability
2. caffeine like effects - headache, nausea, diarrhoea, trouble sleeping
3. increase in urination

Question 8

Interactions

Answer 8

reacts with pretty much everything!!!

Question 9

Elinination

Answer 9

urine