THEOLAIR
Clinical safety rating
cautionComprehensive clinical and safety monograph for THEOLAIR (THEOLAIR).
Theophylline, the active ingredient in THEOLAIR, is a phosphodiesterase inhibitor that increases intracellular cAMP levels, leading to bronchodilation via smooth muscle relaxation. It also has anti-inflammatory effects and may enhance diaphragmatic contractility.
| Metabolism | Primarily hepatic via CYP1A2 and CYP3A4; also metabolized by N-demethylation and oxidation. Approximately 10% excreted unchanged in urine. |
| Excretion | Renal (10% unchanged); hepatic metabolism (90%) with metabolites excreted in urine |
| Half-life | Adults: 3-8 hours (mean 5.5); children: 1.5-5 hours; increased in hepatic cirrhosis, heart failure, and COPD; decreased in smokers |
| Protein binding | 40% bound, primarily to albumin |
| Volume of Distribution | 0.45 L/kg; approximates total body water; higher in infants |
| Bioavailability | Oral: 96% (immediate release); sustained release: 80-100% |
| Onset of Action | Oral: 15-30 min (non-sustained release); sustained release: 1-2 hours; IV: immediate |
| Duration of Action | Oral immediate release: 4-6 hours; sustained release: 8-12 hours; IV: varies with infusion rate |
| Molecular Weight | 180.16 |
Initial dose: 300 mg orally every 8-12 hours; titrate based on serum theophylline levels to achieve 5-15 mcg/mL. Maintenance: 400-600 mg/day in divided doses.
| Dosage form | TABLET |
| Renal impairment | GFR < 30 mL/min: reduce dose by 50% and monitor serum levels. GFR 30-50 mL/min: reduce dose by 25%. |
| Liver impairment | Child-Pugh Class B: reduce dose by 50%. Class C: reduce dose by 75% or use alternative. |
| Pediatric use | Children 1-9 years: starting dose 10-16 mg/kg/day orally in divided doses every 4-6 hours; max 600 mg/day. Children 9-16 years: 10-16 mg/kg/day; max 800 mg/day. Adjust based on serum levels (5-15 mcg/mL). |
| Geriatric use | Start at lower end of dosing range (300 mg/day), titrate slowly with close monitoring of serum levels due to decreased clearance. |
| 1st trimester | Theophylline crosses the placenta; data are limited but no major teratogenic risk identified; use only if clearly needed. |
| 2nd trimester | Monitor maternal serum levels closely as clearance may increase; dose adjustments may be necessary; avoid toxicity. |
| 3rd trimester | Neonatal theophylline toxicity may occur (irritability, jitteriness, tachycardia); avoid near term if possible; monitor neonate. |
Clinical note
Comprehensive clinical and safety monograph for THEOLAIR (THEOLAIR).
| Placental transfer | Theophylline crosses the placenta freely; umbilical cord plasma concentrations approximate maternal levels. |
| Breastfeeding | Theophylline is excreted into breast milk at low concentrations (about 1% of maternal dose). Peak milk levels occur 1-2 hours after dose. Although generally considered compatible with breastfeeding, observe infant for irritability or insomnia if maternal doses are high. |
| Lactation Rating | L2 (probably compatible) |
| Teratogenic Risk | Theophylline (active ingredient in THEOLAIR) is classified as FDA Pregnancy Category C. Human data do not indicate a major teratogenic risk; however, a small increased risk of congenital anomalies cannot be excluded. First trimester: No consistent evidence of teratogenicity; some studies suggest possible association with cardiac defects. Second/third trimester: May cause fetal tachycardia, irritability, and jitteriness due to transplacental passage; neonatal withdrawal symptoms possible. Avoid use near term if possible. |
| Fetal Monitoring | Monitor maternal serum theophylline levels (target 5–15 mcg/mL), heart rate, and respiratory status. Monitor fetal heart rate for tachycardia. Perform ultrasound for fetal growth and anatomy if used in first trimester. Assess neonatal vital signs and behavior after delivery. |
| Fertility Effects | No known adverse effects on fertility in humans. Animal studies have not shown impaired fertility. Theophylline does not appear to affect ovulation or spermatogenesis. However, uncontrolled asthma may impair maternal and fetal outcomes. |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
Hypersensitivity to theophylline or any componentSeizure disorder (unless adequately controlled with anticonvulsants)
| Precautions | Narrow therapeutic index; monitor serum theophylline levels to avoid toxicity., Risk of serious cardiovascular events (e.g., arrhythmias, seizures) at high serum concentrations., May exacerbate peptic ulcer disease., Use caution in patients with hypoxemia, hypertension, or heart failure., Drug interactions: cimetidine, fluoroquinolones, macrolides, and other CYP450 inhibitors increase levels; phenytoin, rifampin, and smoking decrease levels. |
| Food/Dietary | Dietary changes that affect CYP1A2 activity alter theophylline clearance. High-protein, low-carbohydrate diets increase clearance; high-carbohydrate, low-protein diets decrease clearance. Charcoal-broiled meats and cruciferous vegetables (e.g., broccoli, cabbage) induce metabolism, reducing efficacy. Caffeine-containing foods and beverages can potentiate toxicity and should be limited. Consistent dietary habits are critical to maintain stable serum levels. |
| Clinical Pearls | Theophylline (THEOLAIR) has a narrow therapeutic index (5-15 mg/L). Monitor serum levels due to inter- and intra-patient variability. Coadministration with CYP1A2 inhibitors (e.g., cimetidine, fluoroquinolones) or inducers (e.g., phenytoin, smoking) requires dose adjustments. Use with caution in patients with hepatic impairment, congestive heart failure, or fever, as clearance is reduced. |
| Patient Advice | Take exactly as prescribed; do not double the dose if missed. · Avoid changes in smoking habits, diet, or new medications without consulting your doctor. · Report nausea, vomiting, insomnia, rapid heart rate, or seizures immediately. · Do not consume large amounts of caffeine (coffee, tea, chocolate) as it may increase side effects. · Maintain consistent intake of high-protein or low-protein diets. · Store at room temperature away from moisture and heat. |
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