Tox: methylxanthines

Question 1

3 agents that fall into this category

Answer 1

1) caffeine
2) theophylline
3) Theobromine

Question 2

Therapeutic uses for caffeine

Answer 2

Alertness, weight loss, migraine tx, neonatal apnea/bradycardia

Question 3

Medicinal use of theophylline

Answer 3

Old treatment for asthma, COPD (larger replaced by safer newer agents)

Question 4

What can theobromine be found in?

Answer 4

chocolate, various teas

Question 5

MOA of methylxanthine toxicity

Answer 5

Triggers release of preformed epinephrine and norepi –> adrenergic stimulation, beta adrenergic activation, hypokalemia.
PDEi inhibition.
Adenosine receptor antagonism

Question 6

SS of methylxanthine toxicity

Answer 6

Severe n/v in majority of pts.
CNS stimulation: elevated mood, nervousness, agitation, seizures.
CVD stimulation: +HR, BP, dysrhythmias.
High concentrations -> peripheral vasodilation, hypoTN

Question 7

Monitoring of theophylline toxicity

Answer 7

repeat serum levels q2-4hrs until peak and then monitor decline.