Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
TUXARIN ER vs DELSYM
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
TUXARIN ER contains dextromethorphan, an NMDA receptor antagonist and sigma-1 receptor agonist, and bupropion, a norepinephrine and dopamine reuptake inhibitor. The combination is thought to modulate glutamatergic neurotransmission and enhance dopaminergic and noradrenergic signaling.
Dextromethorphan is a non-competitive NMDA receptor antagonist and sigma-1 receptor agonist, which suppresses cough by elevating the threshold for coughing in the medullary cough center.
Major depressive disorder (FDA-approved as Auvelity),Treatment-resistant depression (off-label)
Symptomatic relief of cough caused by minor throat and bronchial irritation
1 tablet orally every 12 hours; each tablet contains chlorpheniramine maleate 8 mg and phenylephrine HCl 20 mg.
60 mg orally every 12 hours (extended-release suspension).
The terminal elimination half-life (t1/2) of chlorpheniramine is approximately 14–25 h in adults, allowing twice-daily dosing. Pseudoephedrine has a shorter t1/2 of 5–8 h in normal renal function, but the ER formulation maintains therapeutic levels for 12 h. In renal impairment, pseudoephedrine half-life prolongs significantly, requiring dose adjustment.
Terminal elimination half-life of dextromethorphan is approximately 11 hours (range 9-14 hours) in extensive metabolizers; in poor metabolizers (CYP2D6 deficiency), half-life can exceed 24 hours, leading to accumulation.
Bupropion is extensively metabolized via CYP2B6 to hydroxybupropion, while dextromethorphan is metabolized primarily by CYP2D6 to dextrorphan. Both are further metabolized by other enzymes.
Metabolized primarily by CYP2D6 to dextrorphan, an active metabolite; also undergoes O-demethylation and N-demethylation.
TUXARIN ER is a combination antihistamine/decongestant. The antihistamine component (e.g., chlorpheniramine) is extensively metabolized via CYP450; its metabolites and parent drug (∼68% over 48 h) appear in urine as unchanged drug and metabolites. The decongestant (e.g., pseudoephedrine) is primarily excreted unchanged in urine (∼70–90%) with the remainder metabolized in liver; renal elimination is p H-dependent, with acidic urine increasing excretion. Fecal elimination is negligible (<5%).
Renal excretion of unchanged drug and metabolites, primarily dextrorphan glucuronide; <5% excreted unchanged in urine. Biliary/fecal elimination is negligible.
Chlorpheniramine: ∼70% bound to plasma proteins (mainly albumin). Pseudoephedrine: negligible protein binding (<20%).
~45-50% bound to plasma albumin; main binding protein is albumin.
Chlorpheniramine: Vd ≈ 3–5 L/kg, indicating extensive tissue distribution. Pseudoephedrine: Vd ≈ 2.5–3.5 L/kg, consistent with distribution into total body water. Larger Vd suggests sequestration in tissues like lungs and spleen.
5-6 L/kg, indicating extensive tissue distribution.
Chlorpheniramine: Oral bioavailability ∼25–50% due to first-pass metabolism. Pseudoephedrine: Oral bioavailability ∼100% (>90% absorbed, low first-pass effect). The ER formulation maintains equivalent bioavailability with reduced peak concentrations.
Oral: ~10-25% due to extensive first-pass metabolism (CYP2D6 and CYP3A4); bioavailability is higher in poor metabolizers.
Contraindicated in severe renal impairment (Cr Cl <30 m L/min). No specific dose adjustment for mild to moderate impairment; use with caution.
No dose adjustment recommended for mild-to-moderate renal impairment; safety in severe renal impairment not established.
Contraindicated in severe hepatic impairment (Child-Pugh class C). Use with caution in moderate impairment (Child-Pugh class B); no specific dose adjustment defined.
No dose adjustment recommended for mild-to-moderate hepatic impairment; safety in severe hepatic impairment not established.
Not recommended for children under 12 years. For children 12 years and older, same as adult dosing: 1 tablet every 12 hours.
Children 6-11 years: 30 mg orally every 12 hours. Children 12 years and older: 60 mg orally every 12 hours. Do not exceed 60 mg in 24 hours for ages 6-11 or 120 mg for ages 12+.
Use with caution due to increased sensitivity to anticholinergic effects (e.g., confusion, urinary retention). Lower initial dose may be considered; avoid use in patients with prostate hypertrophy or glaucoma.
Start at low end of dosing range; monitor for anticholinergic effects and sedation. No specific dose adjustment in elderly but caution due to increased sensitivity.
WARNING: SUICIDALITY AND ANTIDEPRESSANT DRUGS - Antidepressants increased the risk of suicidal thinking and behavior in children, adolescents, and young adults in short-term studies. Monitor closely for clinical worsening and emergence of suicidal thoughts and behaviors.
None
Increased risk of suicidal thoughts and behaviors; activation of mania/hypomania; seizures (dose-dependent); increased blood pressure; angle-closure glaucoma; serotonin syndrome; hepatotoxicity; neuropsychiatric reactions; allergic and anaphylactic reactions.
Do not use in children under 4 years of age,Avoid use with MAO inhibitors or for 2 weeks after stopping,Chronic use may lead to dependence and abuse,Caution in patients with respiratory depression, asthma, or chronic obstructive pulmonary disease
Concurrent use with MAOIs; seizure disorder; history of anorexia nervosa or bulimia; abrupt discontinuation of alcohol, benzodiazepines, or anticonvulsants; known hypersensitivity to any component; use of other bupropion-containing products; concomitant use with linezolid or methylene blue.
Hypersensitivity to dextromethorphan or any component,Use with or within 14 days of MAO inhibitors,Use in patients with respiratory depression or severe asthma
Avoid alcohol and grapefruit juice. Grapefruit juice may inhibit CYP3A4 metabolism of triprolidine, increasing its levels. High-tyramine foods (e.g., aged cheeses, cured meats) may interact with pseudoephedrine, increasing pressor effects. Take with or without food; food may reduce GI irritation but does not affect absorption.
No significant food interactions. Avoid grapefruit juice as it may increase dextromethorphan levels. Take with or without food.
TUXARIN ER contains chlorpheniramine and pseudoephedrine. Chlorpheniramine is an antihistamine classified as FDA Pregnancy Category B; animal studies show no risk but no adequate human studies. Pseudoephedrine is FDA Pregnancy Category C; in first trimester, case-control studies suggest a possible association with gastroschisis (odds ratio ~1.8-2.2). After 32 weeks, use may cause premature uterine contractions or fetal tachycardia. Avoid in third trimester due to risk of neonatal irritability and respiratory depression.
Category D (positive evidence of human fetal risk): First trimester exposure associated with rare reports of congenital malformations including cardiac defects and oral clefts based on observational studies. Second and third trimester use may cause fetal respiratory depression, bradycardia, and neonatal adaptation syndrome with prolonged use near term. Risks increase with higher doses and chronic use.
Chlorpheniramine is excreted into breast milk in small amounts (M/P ratio not established). Pseudoephedrine is excreted into breast milk; M/P ratio approximately 3. Initial data indicate pseudoephedrine may reduce milk production by up to 24% with single doses. Use with caution; avoid in cases of established lactation insufficiency. American Academy of Pediatrics considers both drugs compatible with breastfeeding but may cause irritability in infants.
Excreted into breast milk in low concentrations (M/P ratio 0.1–0.4). Considered compatible with breastfeeding by American Academy of Pediatrics; however, monitor infant for drowsiness, respiratory depression, and poor feeding. Avoid if infant is premature or has respiratory compromise. Use shortest duration possible.
No formal dose adjustments established for pregnancy. However, increased plasma volume and renal clearance in pregnancy may reduce pseudoephedrine levels; monitor clinical response. Avoid extended-release formulations if rapid BP fluctuations are a concern. Consider using the lowest effective dose for shortest duration.
No pharmacokinetic studies show significant changes in dextromethorphan clearance during pregnancy. Therefore, no empiric dose adjustment is recommended. However, because of increased plasma volume and renal blood flow in pregnancy, the duration of action may be shorter, requiring more frequent dosing if clinically indicated. Use lowest effective dose for shortest duration.
TUXARIN ER is a fixed-dose combination of pseudoephedrine (120 mg) and triprolidine (2.5 mg) in an extended-release formulation. The delayed-release component may reduce dosing frequency to every 12 hours. Monitor for CNS stimulation; avoid in severe hypertension or coronary artery disease. Use caution in elderly due to anticholinergic effects (triprolidine).
DELSYM (dextromethorphan polistirex) is a sustained-release formulation providing up to 12 hours of cough suppression. Do not crush or chew capsules; swallow whole. Avoid use in patients with asthma, COPD, or respiratory insufficiency due to risk of respiratory depression. Contraindicated with MAOIs and within 14 days of MAOI use due to serotonin syndrome risk. Not recommended for chronic cough or cough associated with excessive secretions. Use caution in patients with G6PD deficiency (rare hemolysis risk).
Do not crush or chew the tablet; swallow whole with a full glass of water.,Take every 12 hours; do not exceed 2 tablets in 24 hours.,Avoid driving or operating heavy machinery until you know how this medication affects you.,Notify your doctor if you have high blood pressure, heart disease, glaucoma, or urinary retention.,Do not use with other products containing antihistamines or decongestants.,Stop use and seek medical attention if you experience chest pain, rapid heartbeat, or severe dizziness.
Take DELSYM only as directed for temporary cough relief.,Swallow capsules whole; do not crush, chew, or dissolve.,Do not exceed recommended dose or use for more than 7 days unless directed by a doctor.,Avoid alcohol while taking this medication.,Do not use if you are taking or have taken a monoamine oxidase inhibitor (MAOI) within the last 14 days.,Seek medical attention if cough persists, comes with fever, rash, or headache, or if you experience signs of serotonin syndrome (agitation, hallucinations, rapid heart rate, fever, muscle stiffness).,Keep out of reach of children; accidental overdose may cause death.
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 TUXARIN ER vs DELSYM, answered by our medical review team.
TUXARIN ER is a Antitussive/decongestant combination that works by TUXARIN ER contains dextromethorphan, an NMDA receptor antagonist and sigma-1 receptor agonist, and bupropion, a norepinephrine and dopamine reuptake inhibitor. The combination is thought to modulate glutamatergic neurotransmission and enhance dopaminergic and noradrenergic signaling.. DELSYM is a Antitussive that works by Dextromethorphan is a non-competitive NMDA receptor antagonist and sigma-1 receptor agonist, which suppresses cough by elevating the threshold for coughing in the medullary cough center.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between TUXARIN ER and DELSYM depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of TUXARIN ER is: 1 tablet orally every 12 hours; each tablet contains chlorpheniramine maleate 8 mg and phenylephrine HCl 20 mg.. The standard adult dose of DELSYM is: 60 mg orally every 12 hours (extended-release suspension).. 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 TUXARIN ER and DELSYM 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. TUXARIN ER is classified as Category C. TUXARIN ER contains chlorpheniramine and pseudoephedrine. Chlorpheniramine is an antihistamine classified as FDA Pregnancy Category B; animal studies show no risk but no adequate h. DELSYM is classified as Category C. Category D (positive evidence of human fetal risk): First trimester exposure associated with rare reports of congenital malformations including cardiac defects and oral clefts base. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.