Controlled medication - Methylxanthines

Question 1

Theophylline (Theochron®)
Dosage form

Answer 1

Tablets, capsules, and liquid

Question 2

Theophylline (Theochron®)
Dosing

Answer 2

Adult dosing
- Acute exacerbation
Loading dose, typically given IV as aminophylline, followed maintenance IV infusion
Chronic management
Smokers: ~16mg/kg/day divided Nonsmokers: ~13mg/kg/day divided
Doses based on serum concentrations
Target range 5-15 mcg/mL Toxic >20 mcg/mL

Question 3

Adverse effects

Answer 3

AE: Insomnia, gastrointestinal upset, hyperactivity, hypotension, tremor
* Dose related toxicity: tachycardia, nausea, vomiting, headache, seizures, arrhythmias
* CI: peptic ulcer disease, arrhythmias, seizure disorders
* DI: Major substrate of CYP 3A4, 1A2, 2E1
o ­concentration: cimetidine, erythromycin,
clarithromycin, ciprofloxacin, ticlopidine
o ̄concentration:phenobarbital,phenytoin, carbamazepine, rifampin; smoking
* PDE III inhibition likely cause for hypotension, tachycardia and nausea