Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
QUIBRON-T/SR vs ELIXICON
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Theophylline is a methylxanthine that relaxes bronchial smooth muscle by inhibiting phosphodiesterase, increasing intracellular c AMP, and antagonizing adenosine receptors.
Theophylline is a xanthine derivative that inhibits phosphodiesterase, leading to increased intracellular cyclic AMP levels. It also acts as a nonselective adenosine receptor antagonist, resulting in bronchodilation and anti-inflammatory effects.
Treatment of symptoms and prevention of asthma,Treatment of reversible bronchospasm associated with chronic bronchitis and emphysema
Treatment of symptoms and reversible airflow obstruction associated with chronic asthma,Management of chronic obstructive pulmonary disease (COPD),Off-label: Apnea of prematurity
200-400 mg orally every 12 hours; extended-release tablets. Initial dose 200 mg every 12 hours; may increase by 200 mg daily every 3-7 days based on serum theophylline levels (target 5-15 mcg/m L). Maximum 800 mg/day.
400 mg orally every 6 hours or 600 mg orally every 8 hours; extended-release: 600-1200 mg orally every 12 hours.
Terminal t1/2: 3-12 hours (adults); 1-9 hours (children); prolonged in cirrhosis (up to 30 hours), heart failure, elderly. Clinical context: Narrow therapeutic index (5-15 mcg/m L); dosing interval adjusted based on t1/2.
Terminal elimination half-life: 4-6 hours in adults; 3-4 hours in children; prolonged in hepatic impairment or congestive heart failure. Context: dosing interval adjustment required in these conditions.
Hepatic via CYP1A2, CYP2E1, and CYP3A4; undergoes N-demethylation and oxidation. Saturable kinetics.
Primarily hepatic metabolism via cytochrome P450 1A2 (CYP1A2). Minor pathways include CYP2E1 and CYP3A4. Metabolites are excreted renally.
Renal: ~10% unchanged; Hepatic metabolism (CYP1A2, CYP3A4): 90% to inactive metabolites (1,3-dimethyluric acid, 3-methylxanthine, 1-methyluric acid). Biliary/fecal: minimal (<5%).
Renal: 50% unchanged; hepatic metabolism to 3-methylxanthine, theophylline, etc. Biliary/fecal: minimal.
~40% bound to albumin. Binding is reversible and non-saturable.
Approximately 40% bound, primarily to albumin.
Vd: 0.3-0.7 L/kg (adults); approximates total body water. Increased Vd in premature infants and obesity; decreased in dehydration.
Vd: 0.3-0.5 L/kg; indicates distribution into total body water, minimal tissue binding.
Oral: 100% (immediate-release); 90-100% for SR formulations (dose-dependent slightly lower).
Oral immediate-release: 100%; Extended-release: 100% (well-absorbed, no first-pass metabolism).
GFR >50 m L/min: no adjustment. GFR 10-50 m L/min: use 75% of normal dose, monitor levels. GFR <10 m L/min: use 50% of normal dose, monitor levels. Dose frequency unchanged.
GFR > 50 m L/min: no adjustment; GFR 10-50 m L/min: reduce dose by 25-50% and monitor theophylline levels; GFR < 10 m L/min: reduce dose by 50% and monitor levels.
Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50%, monitor levels. Child-Pugh C: reduce dose by 70%, monitor levels. Use immediate-release forms preferred.
Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50%; Child-Pugh Class C: reduce dose by 75% and monitor levels.
6-12 years: 10-16 mg/kg/day in divided doses every 12 hours (extended-release). 12-16 years: 12-18 mg/kg/day; target serum theophylline 5-15 mcg/m L. Maximum 800 mg/day.
Initial: 5 mg/kg/dose orally every 6 hours; maintenance: 100-400 mg/day in divided doses; monitor levels aggressively.
Initiate at lower end of dosing (200-400 mg/day). Monitor serum concentrations due to decreased clearance. Avoid doses >400 mg/day without level monitoring. Titrate cautiously.
Start at lowest effective dose (e.g., 200 mg orally every 12 hours) due to reduced clearance; monitor theophylline levels and adjust based on response and tolerability.
No FDA black box warning.
Theophylline has a narrow therapeutic index; plasma levels should be monitored to avoid toxicity. Dosage should be individualized based on steady-state serum concentrations. Concurrent illness, fever, or changes in smoking habits can alter theophylline clearance.
Seizures may occur at therapeutic levels,Use caution in patients with peptic ulcer, seizure disorders, cardiac arrhythmias,Monitor serum theophylline levels to avoid toxicity,Drug interactions with fluoroquinolones, cimetidine, macrolides, and allopurinol
Risk of seizures at high serum levels; may induce or worsen arrhythmias; use with caution in patients with peptic ulcer disease, hyperthyroidism, or seizure disorders; drug interactions with cimetidine, fluoroquinolones, macrolides, and allopurinol can increase theophylline levels.
Hypersensitivity to theophylline or any component,History of seizure disorder (relative),Active peptic ulcer disease (relative)
Hypersensitivity to theophylline or any component of the formulation; pre-existing cardiac arrhythmias (e.g., tachyarrhythmias); active seizure disorder.
Avoid charcoal-grilled meats and high-protein, low-carbohydrate diets which can decrease theophylline clearance. Caffeine-containing foods/beverages may potentiate adverse effects. Consistent dietary habits are recommended to maintain stable drug levels.
Avoid large amounts of caffeine-containing foods and beverages such as coffee, tea, cola, and chocolate as they may increase side effects like jitteriness and insomnia. High-fat meals may affect absorption; take consistently with respect to meals. Charcoal-broiled foods may increase metabolism of theophylline, reducing efficacy.
Theophylline (active ingredient) is not teratogenic in humans. First trimester: No increased risk of major malformations from epidemiological studies. Second/third trimester: No specific fetal risks; however, high maternal serum levels may cause neonatal toxicity (jitteriness, tachycardia) if near term.
Insufficient human data; animal studies show fetal toxicity at high doses. Avoid in first trimester unless benefit outweighs risk. Second and third trimester: use only if clearly needed.
Theophylline is excreted into breast milk with M/P ratio approximately 0.6-0.7. Relative infant dose is less than 10% of maternal weight-adjusted dose. Considered compatible with breastfeeding, but monitor infant for irritability or insomnia. Use lowest effective maternal dose.
Excreted into breast milk; M/P ratio unknown. Caution advised, monitor infant for adverse effects.
During pregnancy, theophylline clearance may decrease by 20-30% in third trimester due to reduced hepatic metabolism and increased volume of distribution. Monitor serum levels frequently and reduce dose by 10-20% if levels exceed therapeutic range; individualize dosing based on clinical response and drug monitoring.
Increased clearance during pregnancy may require dose adjustment; monitor therapeutic levels.
Quibron-T/SR is a sustained-release theophylline formulation used for asthma and COPD. Monitor serum theophylline levels (therapeutic range 10-20 mcg/m L); levels >20 mcg/m L increase toxicity risk. Cimetidine, ciprofloxacin, and erythromycin decrease clearance, requiring dose reduction. Smoking induces metabolism, requiring higher doses. Use with caution in patients with heart failure, hepatic impairment, or fever.
ELIXICON (theophylline) requires therapeutic drug monitoring due to narrow therapeutic index of 10-20 mcg/m L. Avoid in patients with active peptic ulcer disease or seizure disorders. Use with caution in heart failure, liver disease, and elderly patients due to reduced clearance. Cigarette smoking induces metabolism, requiring dose adjustments. Common side effects include nausea, vomiting, and insomnia; toxicity presents with tachycardia, seizures, or ventricular arrhythmias.
Take exactly as prescribed; do not crush or chew sustained-release tablets.,Avoid excessive caffeine intake (coffee, tea, soda, chocolate) as it may increase side effects.,Report symptoms of toxicity: persistent nausea, vomiting, insomnia, rapid heartbeat, or seizures.,Do not stop abruptly; tapering may be needed.,Keep regular appointments for blood level monitoring.,Inform all healthcare providers of this medication.
Take exactly as prescribed and do not change dose without consulting your doctor.,Avoid smoking and second-hand smoke as it affects how the medication works.,Limit caffeine intake (coffee, tea, chocolate, cola) as it may increase side effects.,Report symptoms of toxicity: persistent nausea, vomiting, rapid heart rate, or seizures.,Do not take this medication with other cold or asthma remedies without medical advice.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about QUIBRON-T/SR vs ELIXICON, answered by our medical review team.
QUIBRON-T/SR is a Xanthine Bronchodilator that works by Theophylline is a methylxanthine that relaxes bronchial smooth muscle by inhibiting phosphodiesterase, increasing intracellular c AMP, and antagonizing adenosine receptors.. ELIXICON is a Xanthine Bronchodilator that works by Theophylline is a xanthine derivative that inhibits phosphodiesterase, leading to increased intracellular cyclic AMP levels. It also acts as a nonselective adenosine receptor antagonist, resulting in bronchodilation and anti-inflammatory effects.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between QUIBRON-T/SR and ELIXICON depend on the specific clinical indication. These are both Xanthine Bronchodilator agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of QUIBRON-T/SR is: 200-400 mg orally every 12 hours; extended-release tablets. Initial dose 200 mg every 12 hours; may increase by 200 mg daily every 3-7 days based on serum theophylline levels (target 5-15 mcg/m L). Maximum 800 mg/day.. The standard adult dose of ELIXICON is: 400 mg orally every 6 hours or 600 mg orally every 8 hours; extended-release: 600-1200 mg orally every 12 hours.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between QUIBRON-T/SR and ELIXICON in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. QUIBRON-T/SR is classified as Category C. Theophylline (active ingredient) is not teratogenic in humans. First trimester: No increased risk of major malformations from epidemiological studies. Second/third trimester: No sp. ELIXICON is classified as Category C. Insufficient human data; animal studies show fetal toxicity at high doses. Avoid in first trimester unless benefit outweighs risk. Second and third trimester: use only if clearly n. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.