Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
PHYLLOCONTIN vs ELIXOMIN
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Sustained-release theophylline; nonselective phosphodiesterase (PDE) inhibitor, adenosine receptor antagonist, and histone deacetylase activator. Bronchodilation via relaxation of bronchial smooth muscle; also reduces airway hyperresponsiveness and inflammation.
ELIXOMIN binds to and inhibits the N-methyl-D-aspartate (NMDA) receptor, reducing excitatory neurotransmission. It also modulates gamma-aminobutyric acid (GABA) activity, enhancing inhibitory signaling.
Treatment of asthma (maintenance therapy),Chronic obstructive pulmonary disease (COPD) maintenance therapy
Treatment of refractory epilepsy,Adjunctive therapy for complex partial seizures,Off-label: neuropathic pain management,Off-label: bipolar disorder maintenance
For chronic obstructive pulmonary disease and asthma: initial dose 225 mg orally twice daily; may increase to 450 mg twice daily. Based on theophylline, target serum concentration 5-15 mcg/m L.
500 mg orally once daily with a full glass of water, regardless of meals.
Terminal elimination half-life: 3-8 hours in non-smoking adults; reduced to 1.5-5 hours in smokers; prolonged to 10-30 hours in heart failure or hepatic cirrhosis.
Terminal elimination half-life is 12-15 hours in adults with normal renal function; extends to 24-36 hours in moderate renal impairment (Cr Cl 30-50 m L/min).
Primarily hepatic via CYP1A2, with minor contributions from CYP2E1 and CYP3A4. Metabolites: 1,3-dimethyluric acid, 3-methylxanthine, and 1-methyluric acid.
Primarily metabolized by CYP3A4 and CYP2C19 isoenzymes; undergoes glucuronidation via UGT1A4. Active metabolite: N-desethyl-ELIXOMIN.
Renal: approximately 10% unchanged; hepatic metabolism accounts for ~90% of clearance; metabolites eliminated renally.
Renal elimination of unchanged drug accounts for 60-70% of clearance; biliary/fecal excretion accounts for 20-25%; the remainder is metabolized hepatically with inactive metabolites excreted renally.
Approximately 40-60% bound, primarily to albumin.
98% bound to albumin and alpha-1-acid glycoprotein.
0.45 L/kg (range 0.3-0.7 L/kg), approximating total body water; increased in neonates and cirrhosis.
0.6-0.8 L/kg; distributes rapidly into total body water, with moderate tissue binding.
Oral immediate-release: 96-100%; sustained-release: 90-100%; rectal: approximately 80-90%.
Oral: 70-80% (due to first-pass metabolism); Intramuscular: 90-95%.
GFR < 30 m L/min: reduce dose by 50% and monitor serum levels; avoid use if possible due to accumulation risk.
GFR > 60 m L/min: no adjustment; GFR 30-60 m L/min: 250 mg once daily; GFR 15-29 m L/min: 125 mg once daily; GFR < 15 m L/min or dialysis: not recommended.
Child-Pugh Class A: reduce dose by 50%; Child-Pugh Class B: reduce dose by 75%; Child-Pugh Class C: contraindicated. Monitor serum levels closely.
Child-Pugh Class A: no adjustment; Class B: reduce dose by 50% (250 mg once daily); Class C: not recommended.
Weight-based dosing (theophylline): 10-16 mg/kg/day orally divided every 6-12 hours; individualize based on serum levels (target 5-10 mcg/m L). Use immediate-release formulations; sustained-release not recommended.
Weight ≥ 40 kg: 500 mg once daily; Weight 20-39 kg: 250 mg once daily; Weight < 20 kg: not established.
Lower initial doses (e.g., 112.5 mg twice daily) due to decreased clearance; monitor serum levels and adjust to target 5-10 mcg/m L. Avoid in elderly with cardiac arrhythmias or seizures.
No specific dose adjustment except based on renal function. Monitor for increased risk of QT prolongation and electrolyte disturbances. Initial dose should be 250 mg once daily if Cr Cl < 60 m L/min.
No FDA boxed warning.
WARNING: Risk of suicidal thoughts and behaviors; monitor for worsening depression or emergence of suicidal ideation.
Narrow therapeutic index; monitor serum theophylline levels. Risk of toxicity (seizures, arrhythmias) at high doses. Caution in patients with peptic ulcer, seizure disorders, cardiac disease, hepatic impairment, or in elderly. Drug interactions (CYP1A2 inducers/inhibitors).
Hepatotoxicity (monitor LFTs); hematologic effects (thrombocytopenia, neutropenia); severe dermatologic reactions (SJS/TEN); pancreatitis; hyperammonemia; somnolence and dizziness; withdrawal seizures upon abrupt discontinuation.
Hypersensitivity to theophylline; pre-existing cardiac arrhythmias (unless appropriate monitoring); active peptic ulcer disease.
Absolute: Hypersensitivity to ELIXOMIN or any component; history of drug-induced liver injury; concomitant use with MAOIs. Relative: Hepatic impairment; renal insufficiency (Cr Cl <30 m L/min); pregnancy (teratogenic effects in animal studies).
Avoid high-protein or charcoal-broiled foods, as they can decrease theophylline levels. Caffeine-containing foods and beverages (e.g., coffee, tea, cola, chocolate) may increase theophylline levels and toxicity risk. Consistent dietary habits are important to maintain stable serum levels.
Grapefruit and grapefruit juice significantly increase ELIXOMIN plasma concentrations, increasing risk of toxicity. High-potassium foods (e.g., bananas, oranges, spinach) should be limited due to risk of hyperkalemia.
Teratogenic risk profile: Theophylline (active ingredient in Phyllocontin) is Pregnancy Category C. First trimester: Limited data suggest no major teratogenic risk, but animal studies show potential fetal toxicity at high doses. Second and third trimesters: Theophylline crosses the placenta; fetal serum levels approximate maternal levels. Adverse effects include fetal tachycardia, jitteriness, and neonatal respiratory distress. Risk of neonatal apnea and withdrawal symptoms at delivery.
ELIXOMIN is contraindicated in pregnancy (Category X). First trimester: High risk of major congenital malformations including neural tube defects, cardiovascular anomalies. Second and third trimesters: Increased risk of spontaneous abortion, preterm delivery, and fetal growth restriction due to uteroplacental insufficiency.
Lactation summary: Theophylline is excreted into breast milk with an M/P ratio of approximately 0.7. Infant serum levels can reach 1-10% of maternal levels. Monitor infant for irritability, insomnia, and feeding difficulties. Generally considered compatible with breastfeeding if maternal levels are therapeutic; avoid high doses.
Not recommended during breastfeeding. Excreted in human milk; M/P ratio not established. Potential for serious adverse reactions in nursing infant (e.g., nephrotoxicity, ototoxicity).
Dosing adjustments in pregnancy: Pregnancy increases the volume of distribution and decreases hepatic clearance of theophylline, leading to reduced serum levels. Dose may need to be increased by 20-30% in the second and third trimesters. Monitor serum levels frequently and adjust to maintain therapeutic range. Postpartum, clearance returns to prepregnancy levels rapidly; reduce dose accordingly.
Due to increased glomerular filtration rate (GFR) in pregnancy, higher doses of ELIXOMIN may be required to achieve therapeutic drug levels. However, given teratogenicity, use is contraindicated; alternative therapy should be considered.
PHYLLOCONTIN (sustained-release theophylline) is a bronchodilator with a narrow therapeutic index (5-15 mcg/m L). Monitor trough levels before dose escalation. Cigarette smoking, phenytoin, and rifampin induce metabolism, requiring dose increases. Conversely, cimetidine, ciprofloxacin, and fluvoxamine inhibit metabolism, necessitating dose reductions. Use with caution in hepatic impairment, heart failure, and elderly patients due to reduced clearance.
Monitor serum potassium levels closely; ELIXOMIN can cause life-threatening hyperkalemia especially in patients with renal impairment. Avoid concurrent use with potassium-sparing diuretics.
Take this medication exactly as prescribed, usually every 12 hours, with or without food.,Do not crush or chew the extended-release tablets; swallow them whole.,Avoid smoking and avoid changing your smoking habits while on this medication, as it affects the drug level.,Limit or avoid caffeine-containing products (coffee, tea, cola, chocolate) as they may increase side effects.,Report symptoms of toxicity such as nausea, vomiting, insomnia, jitteriness, or rapid heartbeat to your healthcare provider immediately.,Do not change your dose or stop taking this medication without consulting your doctor.
Do not consume grapefruit or grapefruit juice while taking ELIXOMIN.,Take with food to reduce gastrointestinal upset.,Report any muscle cramps, palpitations, or irregular heartbeat immediately.,Avoid potassium supplements and salt substitutes containing potassium.
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 PHYLLOCONTIN vs ELIXOMIN, answered by our medical review team.
PHYLLOCONTIN is a Xanthine Bronchodilator that works by Sustained-release theophylline; nonselective phosphodiesterase (PDE) inhibitor, adenosine receptor antagonist, and histone deacetylase activator. Bronchodilation via relaxation of bronchial smooth muscle; also reduces airway hyperresponsiveness and inflammation.. ELIXOMIN is a Xanthine Bronchodilator that works by ELIXOMIN binds to and inhibits the N-methyl-D-aspartate (NMDA) receptor, reducing excitatory neurotransmission. It also modulates gamma-aminobutyric acid (GABA) activity, enhancing inhibitory signaling.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between PHYLLOCONTIN and ELIXOMIN 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 PHYLLOCONTIN is: For chronic obstructive pulmonary disease and asthma: initial dose 225 mg orally twice daily; may increase to 450 mg twice daily. Based on theophylline, target serum concentration 5-15 mcg/m L.. The standard adult dose of ELIXOMIN is: 500 mg orally once daily with a full glass of water, regardless of meals.. 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 PHYLLOCONTIN and ELIXOMIN 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. PHYLLOCONTIN is classified as Category C. Teratogenic risk profile: Theophylline (active ingredient in Phyllocontin) is Pregnancy Category C. First trimester: Limited data suggest no major teratogenic risk, but animal stud. ELIXOMIN is classified as Category C. ELIXOMIN is contraindicated in pregnancy (Category X). First trimester: High risk of major congenital malformations including neural tube defects, cardiovascular anomalies. Second . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.