THEOPHYLLINE 0.32% AND DEXTROSE 5% IN PLASTIC CONTAINER
Clinical safety rating: safe
Many drugs can increase (eg ciprofloxacin) or decrease (eg phenytoin) levels due to CYP1A2 metabolism Has a narrow therapeutic index and can cause seizures and arrhythmias in overdose.
Theophylline is a phosphodiesterase inhibitor that increases intracellular cAMP levels, leading to bronchodilation via smooth muscle relaxation. It also acts as an adenosine receptor antagonist and may enhance diaphragmatic contractility.
| Metabolism | Primarily hepatic via CYP1A2 (major), CYP2E1, and CYP3A4. Major metabolite is 3-methylxanthine. Less than 15% excreted unchanged in urine. |
| Excretion | Renal (90% as metabolites, 10% unchanged). Biliary/fecal <5%. |
| Half-life | Adults: 6-12 hr (mean 8.7); smokers: 4-6 hr; children: 3-5 hr; neonates: 24-36 hr. Prolonged in hepatic/cardiac disease. |
| Protein binding | Approximately 40% bound to albumin. |
| Volume of Distribution | 0.45 L/kg (range 0.3-0.7 L/kg). Indicates distribution into total body water. |
| Bioavailability | Oral immediate-release: 96-100%; Oral sustained-release: 80-100% (dose-dependent). |
| Onset of Action | IV: immediate; Oral immediate-release: 30-60 min; Oral sustained-release: 1-2 hr. |
| Duration of Action | IV: 6-8 hr; Oral immediate-release: 6-8 hr; Oral sustained-release: 12-24 hr; dependent on clearance. |
Loading dose: 5-6 mg/kg IV over 20-30 minutes (if not on theophylline); maintenance IV infusion: 0.4-0.6 mg/kg/h for nonsmoking adults, 0.6-0.9 mg/kg/h for smokers, targeted to serum concentration 10-20 mcg/mL.
| Dosage form | INJECTABLE |
| Renal impairment | No specific dose adjustment required for GFR reduction; monitor serum concentrations and adjust accordingly. |
| Liver impairment | Child-Pugh Class A: reduce dose by 50%; Child-Pugh Class B: reduce dose by 60%; Child-Pugh Class C: reduce dose by 80% or use alternative therapy. |
| Pediatric use | Loading dose: 5-6 mg/kg IV over 20-30 minutes; maintenance IV infusion: 0.5-0.7 mg/kg/h for ages 1-9 years, 0.4-0.5 mg/kg/h for ages 9-12 years, 0.3-0.4 mg/kg/h for ages 12-16 years; target serum concentration 10-20 mcg/mL. |
| Geriatric use | Start at lower end of adult dose (e.g., 0.3-0.4 mg/kg/h) due to decreased clearance; monitor serum concentrations closely and adjust to avoid toxicity. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Many drugs can increase (eg ciprofloxacin) or decrease (eg phenytoin) levels due to CYP1A2 metabolism Has a narrow therapeutic index and can cause seizures and arrhythmias in overdose.
| FDA category | Animal |
| Breastfeeding | Theophylline is excreted into breast milk (M/P ratio approximately 0.6-0.7). Infant serum levels may reach therapeutic range, with risk of irritability and sleep disturbance. Use with caution; monitor infant for signs of toxicity. |
| Teratogenic Risk |
■ FDA Black Box Warning
None.
| Common Effects | COPD |
| Serious Effects |
["Hypersensitivity to theophylline or any component","Pre-existing seizure disorder (unless controlled)","Active peptic ulcer disease"]
| Precautions | ["Narrow therapeutic index; serum concentrations should be monitored to avoid toxicity (desired range 5-15 mcg/mL)","Risk of seizures and arrhythmias at high serum levels","Use with caution in patients with cardiac diseases, hepatic impairment, and elderly","Significant drug interactions (e.g., cimetidine, quinolones decrease clearance; smoking increases clearance)"] |
Loading safety data…
| First trimester: Inadequate human data; animal studies not sufficient to rule out risk. Second and third trimesters: No evidence of major malformations; associations with fetal tachycardia and irritability at high maternal serum levels (>20 mcg/mL). Use only if maternal benefit outweighs fetal risk. |
| Fetal Monitoring | Maternal: serum theophylline levels (target 5-15 mcg/mL), heart rate, signs of toxicity (nausea, vomiting, tachycardia, arrhythmias). Fetal: heart rate monitoring for tachycardia (especially with levels >20 mcg/mL). |
| Fertility Effects | No known adverse effects on human fertility. Animal studies show no impairment of fertility at clinically relevant doses. |