THEOCLEAR-100
Clinical safety rating: caution
Comprehensive clinical and safety monograph for THEOCLEAR-100 (THEOCLEAR-100).
Theophylline relaxes bronchial smooth muscle by inhibiting phosphodiesterase, increasing intracellular cAMP, and antagonizing adenosine receptors.
| Metabolism | Hepatic via CYP1A2 and CYP3A4; also undergoes N-demethylation and oxidation. |
| Excretion | Renal excretion accounts for approximately 10% of the administered dose as unchanged drug. The remainder is hepatically metabolized, with metabolites excreted renally. Biliary/fecal elimination is negligible (<5%). |
| Half-life | Terminal elimination half-life is approximately 8-12 hours in healthy adults. In smokers, half-life is reduced by 50%; in patients with hepatic cirrhosis or heart failure, half-life is prolonged to 24-36 hours. |
| Protein binding | Approximately 40% bound to albumin in plasma. |
| Volume of Distribution | Apparent volume of distribution is 0.3-0.65 L/kg, reflecting distribution throughout total body water. |
| Bioavailability | Oral immediate-release: 96-100%. Oral sustained-release: 90-100% relative to immediate-release. Rectal: 80-90%. |
| Onset of Action | Oral immediate-release: 15-30 minutes. Oral sustained-release: 1-2 hours. Intravenous: 5-15 minutes. |
| Duration of Action | Immediate-release: 4-6 hours. Sustained-release: 8-12 hours. Duration is dose-dependent and influenced by hepatic function and concurrent medications. |
100 mg orally every 6 hours; adjust based on serum theophylline concentrations and clinical response (target 5-15 mcg/mL).
| Dosage form | TABLET |
| Renal impairment | No specific dose adjustment required for renal impairment; monitor serum levels due to altered pharmacokinetics in severe renal failure (GFR <10 mL/min). |
| Liver impairment | Child-Pugh A: reduce dose by 50%; Child-Pugh B: reduce dose by 75%; Child-Pugh C: contraindicated. |
| Pediatric use | Initial: 5 mg/kg/day orally divided every 6 hours; titrate based on serum levels. Maximum: 16 mg/kg/day (max 400 mg/day) for children >1 year. |
| Geriatric use | Start at lower end of dosing (e.g., 100 mg every 8-12 hours) due to decreased clearance; monitor serum concentrations closely; target 5-10 mcg/mL. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for THEOCLEAR-100 (THEOCLEAR-100).
| Breastfeeding | Theophylline excreted into breast milk with infant serum levels approximately 10% of maternal; M/P ratio ~0.7. Cautious use only if benefits outweigh risks; monitor infant for irritability and poor feeding. |
| Teratogenic Risk | FDA Pregnancy Category C. First trimester: limited data suggest possible increased risk of congenital malformations; second and third trimesters: associated with fetal tachycardia, jitteriness, and respiratory distress; avoid use near term due to risk of neonatal theophylline toxicity. |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
Hypersensitivity to theophylline; porphyria.
| Precautions | Monitor serum levels due to narrow therapeutic index; risk of toxicity (seizures, arrhythmias); use caution in hepatic impairment, heart failure, elderly, and with concurrent medications that alter metabolism. |
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| Fetal Monitoring |
| Monitor maternal serum theophylline levels (target 5-15 mcg/mL), fetal heart rate, and uterine activity; consider periodic ultrasound for fetal growth. |
| Fertility Effects | No data on human fertility impairment; animal studies show no adverse effects on fertility at clinically relevant doses. |