Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
QUIBRON-T/SR vs AMINOPHYLLINE
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.
Aminophylline is a bronchodilator and respiratory stimulator that acts as a non-selective phosphodiesterase inhibitor, increasing cyclic AMP levels, and as an adenosine receptor antagonist. It also enhances diaphragmatic contractility and mucociliary clearance.
Treatment of symptoms and prevention of asthma,Treatment of reversible bronchospasm associated with chronic bronchitis and emphysema
Treatment of acute bronchospasm in asthma and COPD,Treatment of apnea of prematurity,Off-label: adjunctive therapy in COPD exacerbations, status asthmaticus
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.
Loading dose: 5-6 mg/kg IV over 20-30 minutes (if no recent theophylline). Maintenance: 0.4-0.6 mg/kg/hour IV continuous infusion; oral: 300-600 mg/day divided every 6-8 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.
Adults: 7-9 hours (nonsmokers), 4-5 hours (smokers), 10-20 hours (neonates, hepatic impairment, CHF).
Hepatic via CYP1A2, CYP2E1, and CYP3A4; undergoes N-demethylation and oxidation. Saturable kinetics.
Hepatic metabolism via CYP1A2 and xanthine oxidase; demethylation and oxidation yield active metabolites (caffeine and 3-methylxanthine).
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: ~10% unchanged; hepatic metabolism (N-demethylation, oxidation) accounts for >80% of elimination; <1% fecal.
~40% bound to albumin. Binding is reversible and non-saturable.
Approximately 40-60% bound to albumin in adults; lower in neonates (20-30%) and patients with hepatic disease.
Vd: 0.3-0.7 L/kg (adults); approximates total body water. Increased Vd in premature infants and obesity; decreased in dehydration.
0.3-0.7 L/kg (average 0.45 L/kg); increased in neonates, cirrhosis, and CHF.
Oral: 100% (immediate-release); 90-100% for SR formulations (dose-dependent slightly lower).
Oral: ~100% (well-absorbed); Rectal: ~80-100% (variable); IM: ~100% (avoid due to pain and unpredictable absorption).
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.
No specific dose adjustment required based on GFR; monitor theophylline levels closely in renal impairment.
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 A: reduce dose by 25%; Child-Pugh B: reduce dose by 50%; Child-Pugh C: reduce dose by 50-75% or consider alternative.
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.
Oral: 5 mg/kg/dose every 6 hours; IV loading: 5-6 mg/kg; maintenance: 0.5-0.9 mg/kg/hour for ages 6 months-9 years, 0.4-0.5 mg/kg/hour for ages 9-16 years.
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.
Reduce initial dose by 50% (e.g., 0.2-0.3 mg/kg/hour IV) due to decreased clearance; monitor serum theophylline levels and titrate slowly.
No FDA black box warning.
No FDA boxed warning exists; however, use caution in patients with acute myocardial injury due to potential arrhythmias.
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
Narrow therapeutic index requiring monitoring of serum theophylline levels; increased seizure risk at high concentrations; arrhythmia risk; caution in heart failure, hepatic impairment, and elderly.
Hypersensitivity to theophylline or any component,History of seizure disorder (relative),Active peptic ulcer disease (relative)
Hypersensitivity to aminophylline, theophylline, ethylenediamine; uncontrolled arrhythmias; active seizure disorder; peptic ulcer; severe hypertension.
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 high-fat meals which can decrease absorption and lead to variable serum levels. Limit caffeine intake (coffee, tea, cola, chocolate) as it may increase theophylline toxicity and side effects. Charcoal-broiled foods and a high-protein, low-carbohydrate diet may increase clearance of theophylline. Consistently maintain dietary habits to avoid fluctuations in theophylline levels.
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.
Aminophylline is a bronchodilator containing theophylline and ethylenediamine. Theophylline crosses the placenta and fetal serum concentrations approximate maternal levels. In the first trimester, limited data do not indicate a significant increase in major malformations, but the drug should be used only if clearly needed. In the second and third trimesters, theophylline may cause fetal tachycardia, jitteriness, and irritability if maternal levels are high. Near term, accumulation of theophylline in the fetus may lead to neonatal withdrawal (irritability, apnea) and transient tachycardia. Risk is dose-dependent and more pronounced at serum levels >15 mcg/m L.
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.
Theophylline is excreted into breast milk with a milk-to-plasma (M/P) ratio of approximately 0.7. Infant exposure is estimated to be 1–10% of the maternal weight-adjusted dose. Premature infants or those with impaired clearance are at risk for accumulation and toxicity (irritability, jitteriness, feeding intolerance). Breastfeeding is generally considered acceptable if maternal serum levels are within therapeutic range (5-15 mcg/m L) and the infant is monitored for signs of theophylline toxicity. American Academy of Pediatrics classifies theophylline as compatible with breastfeeding, but caution is advised.
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.
Pregnancy increases the clearance of theophylline by approximately 20-30% due to increased volume of distribution and hepatic metabolism (especially in the second and third trimesters). Doses may need to be increased by 20-30% to maintain therapeutic serum levels. Frequent monitoring of serum theophylline levels (every 1-2 weeks) is recommended to guide dose adjustments. Postpartum, clearance returns to prepregnancy levels within 2-3 months, so doses should be reduced to avoid toxicity.
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.
1. Aminophylline is a bronchodilator that is a combination of theophylline and ethylenediamine; the ethylenediamine component may cause allergic reactions in sensitive individuals. 2. Monitor serum theophylline levels closely (therapeutic range: 10-20 mcg/m L); toxicity can occur at levels >20 mcg/m L with symptoms including nausea, vomiting, tachycardia, and seizures. 3. Use with caution in patients with severe hypoxemia, and treat with diltiazem or benzodiazepines for seizures if they occur. 4. Aminophylline can cause significant drug interactions, particularly with cimetidine, fluoroquinolones, and macrolide antibiotics which increase theophylline levels. 5. In acute asthma exacerbations, aminophylline is typically reserved for cases not responding to inhaled beta-agonists and corticosteroids due to narrow therapeutic index.
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 this medication exactly as prescribed; do not chew or crush extended-release tablets.,Avoid consuming large amounts of caffeine (coffee, tea, chocolate, cola) as it may increase side effects such as nervousness and palpitations.,Notify your doctor immediately if you experience nausea, vomiting, irregular heartbeats, or seizures.,Do not smoke or stop smoking without consulting your doctor, as smoking affects how this medication works.,Keep a record of peak flow readings as directed by your healthcare provider.
No interactions on record
"Concurrent administration of aminophylline, a xanthine derivative bronchodilator that is metabolized primarily by CYP1A2 and to a lesser extent CYP3A4, may reduce the clearance of ranolazine, an antianginal agent predominantly metabolized by CYP3A4 and to a lesser extent CYP2D6. Aminophylline can inhibit CYP3A4 activity, leading to increased ranolazine plasma concentrations, which elevates the risk of dose-dependent adverse effects such as QTc prolongation, dizziness, and syncope. This interaction is clinically significant and may necessitate dose adjustment or alternative therapy."
"Asunaprevir, a potent inhibitor of the drug transporter OATP1B1, can significantly decrease the serum concentration of aminophylline, a theophylline salt, likely by reducing its intestinal absorption or increasing its hepatic clearance. This interaction may lead to reduced therapeutic efficacy of aminophylline, potentially worsening respiratory symptoms in patients with asthma or COPD. Close monitoring and dose adjustment of aminophylline are recommended during coadministration with asunaprevir."
"Aminophylline, a bronchodilator, inhibits the metabolism of tibolone, a synthetic steroid hormone used for hormone replacement therapy, primarily through competitive inhibition of cytochrome P450 (CYP) 3A4 isoenzyme. This results in increased plasma concentrations of tibolone and its active metabolites, potentiating its hormonal effects and increasing the risk of adverse events such as thromboembolism, endometrial hyperplasia, or breast tenderness. Clinically, coadministration may require dose adjustments and careful monitoring for signs of estrogenic excess."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about QUIBRON-T/SR vs AMINOPHYLLINE, 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.. AMINOPHYLLINE is a Xanthine Bronchodilator that works by Aminophylline is a bronchodilator and respiratory stimulator that acts as a non-selective phosphodiesterase inhibitor, increasing cyclic AMP levels, and as an adenosine receptor antagonist. It also enhances diaphragmatic contractility and mucociliary clearance.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between QUIBRON-T/SR and AMINOPHYLLINE 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 AMINOPHYLLINE is: Loading dose: 5-6 mg/kg IV over 20-30 minutes (if no recent theophylline). Maintenance: 0.4-0.6 mg/kg/hour IV continuous infusion; oral: 300-600 mg/day divided every 6-8 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 AMINOPHYLLINE 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. AMINOPHYLLINE is classified as Category C. Aminophylline is a bronchodilator containing theophylline and ethylenediamine. Theophylline crosses the placenta and fetal serum concentrations approximate maternal levels. In the . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.