Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
DISOPHROL vs ACTAHIST
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Disophrol is a combination of dexbrompheniramine, a first-generation antihistamine that blocks H1 receptors, and pseudoephedrine, a sympathomimetic amine that stimulates alpha-adrenergic receptors causing vasoconstriction.
Antihistamine; binds to histamine H1 receptors, blocking the effects of histamine; also exhibits anticholinergic and mild sedative properties.
Relief of symptoms of seasonal or perennial allergic rhinitis,Relief of symptoms of vasomotor rhinitis,Relief of nasal congestion associated with the common cold,Relief of sinusitis symptoms
Symptomatic relief of allergic rhinitis,Urticaria,Off-label: motion sickness,Off-label: insomnia
1 tablet (6 mg dexbrompheniramine maleate / 60 mg pseudoephedrine sulfate) orally every 4-6 hours; not to exceed 4 tablets in 24 hours.
1.34 mg (one capsule) orally twice daily.
Terminal elimination half-life is 3-4 hours in adults; in renal impairment, half-life may be prolonged up to 8-12 hours requiring dose adjustment.
6.9 ± 1.7 hours in adults; prolonged to 12-18 hours in elderly or patients with hepatic impairment, requiring dosing interval adjustment.
Dexbrompheniramine is metabolized in the liver primarily via CYP450 enzymes; pseudoephedrine is partially metabolized in the liver by N-demethylation and excreted largely unchanged in urine.
Hepatic metabolism via CYP450 enzymes (primarily CYP3A4 and CYP2D6); major metabolite is inactive.
Renal excretion of unchanged drug and metabolites; approximately 60-70% of a dose eliminated in urine as unchanged drug and glucuronide conjugates, with <10% in feces.
Primarily renal (approximately 85% as unchanged drug and metabolites) and fecal (15%) via biliary elimination.
Approximately 50-60% bound to plasma proteins, primarily albumin.
92% bound to albumin.
Volume of distribution is approximately 1.5-2.5 L/kg, indicating extensive tissue distribution.
0.9 ± 0.3 L/kg, indicating extensive extravascular distribution.
Oral bioavailability is about 70-80% due to first-pass metabolism.
Oral: 68% ± 12% due to first-pass metabolism.
GFR 30-50 m L/min: administer every 6-8 hours. GFR 15-29 m L/min: administer every 12 hours. GFR <15 m L/min: not recommended.
No dose adjustment required for mild to moderate renal impairment. Safety not established for severe impairment (GFR <30 m L/min).
Child-Pugh Class A: no adjustment. Child-Pugh Class B: use with caution, reduce dose frequency. Child-Pugh Class C: contraindicated.
No dose adjustment required for mild to moderate hepatic impairment (Child-Pugh A or B). Not recommended for severe hepatic impairment (Child-Pugh C).
Children 6-11 years: 1/2 tablet (3 mg dexbrompheniramine / 30 mg pseudoephedrine) orally every 4-6 hours, max 2 tablets per day. Children <6 years: not recommended.
Not indicated for pediatric patients under 12 years of age. Safety and efficacy not established.
Initiate with 1/2 tablet every 6-8 hours; monitor for anticholinergic effects and hypertension; avoid in patients >65 years due to increased risk of adverse effects.
No specific dose adjustment recommended; monitor for increased anticholinergic effects and cognitive impairment.
None.
None.
Cardiovascular effects: may cause hypertension, palpitations, arrhythmias,Central nervous system stimulation: may cause insomnia, dizziness, tremor,Urinary retention: use with caution in patients with BPH or urinary obstruction,Increased intraocular pressure: avoid in narrow-angle glaucoma,Elderly patients: more sensitive to anticholinergic and cardiovascular effects
May cause drowsiness; caution when driving or operating machinery. Avoid alcohol. Use with caution in patients with narrow-angle glaucoma, prostatic hyperplasia, or urinary retention. Geriatric patients more sensitive to anticholinergic effects. Pediatric patients <6 years: not recommended.
Severe hypertension,Coronary artery disease,Concurrent use of MAO inhibitors or within 14 days of such therapy,Narrow-angle glaucoma,Urinary retention,Severe renal impairment,Hypersensitivity to any component
Hypersensitivity to any component. Newborns or premature infants. Breastfeeding (contraindicated due to risk of adverse effects in infants). Concomitant use with MAOIs.
Avoid consuming alcohol while taking Disophrol. Caffeine may increase restlessness and insomnia. There is no specific food interaction, but taking with food may reduce gastrointestinal upset.
Avoid high-tyramine foods (aged cheese, cured meats, fermented products) if taking MAOIs. Grapefruit juice may increase phenylephrine absorption; limit intake.
DISOPHROL (dexchlorpheniramine/pseudoephedrine) is classified as FDA Pregnancy Category C. First trimester: Case reports suggest a possible small increased risk of gastroschisis with antihistamine use, but data are limited; pseudoephedrine may be associated with a small risk of gastroschisis and hemifacial microsomia. Second and third trimesters: No specific fetal risks have been clearly established; pseudoephedrine may cause fetal tachycardia and decreased uterine blood flow at high doses. Avoid in third trimester due to potential for uterine contraction inhibition and neonatal respiratory depression from antihistamines.
ACTAHIST (brompheniramine/phenylephrine) pregnancy category C. Inadequate human data; animal studies show no malformations at therapeutic doses. First trimester: theoretical risk from vasoconstrictive effects (phenylephrine) possibly reducing uterine blood flow; avoid if possible. Second/third trimester: phenylephrine may cause fetal hypoxia via placental vasoconstriction; use only if benefit outweighs risk. No known structural teratogenicity.
DISOPHROL is excreted into breast milk. Dexchlorpheniramine: Present in low levels, M/P ratio not established; may cause irritability and drowsiness in infants. Pseudoephedrine: Excreted into breast milk with M/P ratio of approximately 2.6-3.5; may cause infant irritability and decreased milk production. Use caution and monitor infant for excessive drowsiness or irritability.
Brompheniramine is excreted in breast milk in small amounts; M/P ratio not established. Phenylephrine has minimal excretion. Due to anticholinergic effects, may reduce milk production or cause sedation in infants. Use caution; prefer non-sedating alternatives if possible.
No specific dose adjustments are recommended in pregnancy; however, use lowest effective dose and shortest duration. Due to increased plasma volume and renal clearance in pregnancy, pseudoephedrine may have reduced efficacy; dose may need empirical adjustment based on response. Avoid extended-release formulations in pregnancy.
No specific pharmacokinetic studies. Increased plasma volume and renal clearance in pregnancy may reduce drug levels, but efficacy threshold remains. No dose adjustment recommended; use the lowest effective dose for shortest duration due to potential risks.
Disophrol combines an antihistamine (dexbrompheniramine) and a decongestant (pseudoephedrine). Avoid in patients with hypertension, coronary artery disease, or hyperthyroidism due to pseudoephedrine's sympathomimetic effects. Monitor for anticholinergic side effects (drowsiness, dry mouth) from the antihistamine component. Use with caution in glaucoma, urinary retention, and prostatic hypertrophy.
Actahist is a combination antihistamine-decongestant (chlorpheniramine/phenylephrine). Avoid in patients with hypertension, severe coronary artery disease, or MAOI use. Monitor for sedation and urinary retention, especially in elderly males with BPH.
Take this medication as prescribed; do not exceed recommended dose due to risk of serious side effects.,Avoid alcohol and other CNS depressants as they may increase drowsiness.,Do not take with other medications containing decongestants or antihistamines.,Notify your doctor if you have high blood pressure, heart disease, glaucoma, or difficulty urinating.,May cause drowsiness; avoid driving or operating heavy machinery until you know how it affects you.
Take with food or milk to reduce stomach upset.,Avoid alcohol and CNS depressants as they can increase drowsiness.,Do not drive or operate machinery until you know how this medication affects you.,Contact your doctor if you experience chest pain, rapid heartbeat, or difficulty urinating.
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 DISOPHROL vs ACTAHIST, answered by our medical review team.
DISOPHROL is a Antihistamine/Decongestant Combination that works by Disophrol is a combination of dexbrompheniramine, a first-generation antihistamine that blocks H1 receptors, and pseudoephedrine, a sympathomimetic amine that stimulates alpha-adrenergic receptors causing vasoconstriction.. ACTAHIST is a Antihistamine that works by Antihistamine; binds to histamine H1 receptors, blocking the effects of histamine; also exhibits anticholinergic and mild sedative properties.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between DISOPHROL and ACTAHIST 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 DISOPHROL is: 1 tablet (6 mg dexbrompheniramine maleate / 60 mg pseudoephedrine sulfate) orally every 4-6 hours; not to exceed 4 tablets in 24 hours.. The standard adult dose of ACTAHIST is: 1.34 mg (one capsule) orally twice daily.. 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 DISOPHROL and ACTAHIST 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. DISOPHROL is classified as Category C. DISOPHROL (dexchlorpheniramine/pseudoephedrine) is classified as FDA Pregnancy Category C. First trimester: Case reports suggest a possible small increased risk of gastroschisis wi. ACTAHIST is classified as Category C. ACTAHIST (brompheniramine/phenylephrine) pregnancy category C. Inadequate human data; animal studies show no malformations at therapeutic doses. First trimester: theoretical risk f. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.