THEOCLEAR-100
Clinical safety rating
cautionComprehensive 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. |
| Molecular Weight | 180.16 |
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 | Theophylline crosses the placenta. Limited data in first trimester; use only if clearly needed. Risk of fetal tachycardia and irritability. |
| 2nd trimester | Maternal theophylline use may cause neonatal jitteriness, tachycardia, and vomiting. Monitor neonatal serum theophylline if used near term. |
| 3rd trimester | Neonatal toxicity can occur; consider dose reduction in late pregnancy. Avoid if possible near delivery. |
Clinical note
Comprehensive clinical and safety monograph for THEOCLEAR-100 (THEOCLEAR-100).
| Placental transfer | Theophylline readily crosses the placenta with cord blood concentrations similar to maternal serum levels. |
| Breastfeeding | Theophylline is excreted into breast milk in low concentrations (approx 10% of maternal serum level). Highest levels in colostrum. Risk of irritability and poor feeding in infants; monitor infant for signs of caffeine-like effects. Use with caution, especially in premature infants. |
| Lactation Rating | L3 (Moderately Safe) |
| 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. |
| 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. |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
Hypersensitivity to theophylline or any componentSeizure disorder (unless controlled with medication)Pre-existing cardiac arrhythmias (e.g., tachyarrhythmias)Peptic ulcer disease (active)
| 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. |
| Food/Dietary | High-fat meals may slow absorption of some formulations; charcoal-broiled foods and cruciferous vegetables (e.g., broccoli, cabbage) can increase theophylline clearance. Consistent dietary habits are advised to avoid fluctuations in serum levels. |
| Clinical Pearls | Theophylline has a narrow therapeutic index (5-15 mcg/mL). Monitor serum levels due to variable metabolism; CYP1A2 and CYP3A4 inducers (e.g., smoking, rifampin) decrease levels, while inhibitors (e.g., cimetidine, fluoroquinolones) increase toxicity. Use with caution in heart failure, hepatic impairment, and elderly. Tachyphylaxis may occur with prolonged use. |
| Patient Advice | Take exactly as prescribed; do not double doses. · Report symptoms of toxicity: nausea, vomiting, insomnia, irritability, palpitations, seizures. · Avoid smoking or sudden smoking cessation as it alters drug levels. · Limit caffeine intake (coffee, tea, cola, chocolate) to avoid additive stimulant effects. · Do not crush or chew extended-release tablets; swallow whole. |
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