Theophylline
Generic Details
Generic Name
Theophylline
Other Names
- Aminophylline
Drug Class
- Methylxanthine
Chemical Formula
C7H8N4O2
Molecular Weight
180.16 g/mol
Mechanism of Action
- Phosphodiesterase inhibitor
- Adenosine receptor antagonist
Indications
- Asthma
- Chronic obstructive pulmonary disease (COPD)
- Bronchospasm
Common Dosage Forms
- Tablet
- Capsule
- Injection
- Oral solution
Typical Dosage
- 200-400 mg every 6-8 hours
Pediatric Dosage
- 6 mg/kg every 6 hours
Geriatric Dosage
- Lower starting doses may be required due to decreased clearance
Side Effects
- Nausea
- Vomiting
- Headache
- Insomnia
- Restlessness
- Tachycardia
- Seizures (rare)
Contraindications
- Hypersensitivity to theophylline
- Acute myocardial infarction
Pregnancy Category
- C
Lactation Safety
- Limited data - caution advised
Drug Interactions
- Ciprofloxacin
- Cimetidine
- Phenytoin
- Rifampin
Overdose Symptoms
- Severe nausea
- Vomiting
- Tremors
- Cardiac arrhythmias
- Seizures
Antidote for Overdose
- Activated charcoal
- Diazepam for seizures
Storage Conditions
- Store at room temperature away from moisture and heat
Pharmacokinetics
- Absorption: Rapid and complete
- Distribution: Crosses blood-brain barrier, widely distributed in the body
- Metabolism: Mainly hepatic - CYP1A2
- Excretion: Primarily by the kidneys
Precautions
- Monitor serum levels regularly
- Avoid abrupt discontinuation
- Caution in patients with liver or kidney disease
Warnings
- Narrow therapeutic index - monitor levels closely
Others
- Avoid or limit caffeine consumption as it can increase the risk of side effects or toxicity.