Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ACULAR LS vs DIMETANE-DX
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Selective COX-2 inhibitor; inhibits prostaglandin synthesis, reducing ocular inflammation and pain.
Dimetane-DX contains brompheniramine (first-generation antihistamine) and dextromethorphan (NMDA receptor antagonist and sigma-1 agonist). Brompheniramine antagonizes histamine at H1 receptors, reducing allergic symptoms; dextromethorphan suppresses cough by acting on the cough center in the medulla oblongata via NMDA receptor antagonism and sigma-1 receptor activation.
FDA: Treatment of postoperative inflammation in patients who have undergone cataract surgery,Off-label: Relief of ocular pain, photophobia, and inflammation associated with corneal abrasion or refractive surgery
Relief of cough and upper respiratory symptoms associated with allergy or common cold (FDA-approved OTC use)
1 drop in the affected eye(s) four times daily
Adults and children ≥12 years: One tablet (brompheniramine 4 mg, dextromethorphan 10 mg, phenylephrine 10 mg) orally every 4 hours as needed, not to exceed 4 doses in 24 hours.
The terminal elimination half-life is approximately 1.8 hours (range 1.2–2.5 hours) following topical ocular administration. This short half-life is consistent with rapid clearance from the systemic circulation.
Brompheniramine: 25-30 hours; guaifenesin: 1 hour; dextromethorphan: 2-4 hours (CYP2D6 extensive metabolizers) or 20-40 hours (poor metabolizers).
Primarily hepatic via CYP2C9; undergoes glucuronidation and oxidation to inactive metabolites.
Brompheniramine is hepatically metabolized via CYP450 enzymes (primarily CYP2D6). Dextromethorphan is extensively metabolized by CYP2D6 to dextrorphan (active metabolite).
Renal excretion of metabolites and unchanged drug accounts for approximately 26% of the dose. Fecal excretion accounts for approximately 74% of the dose, primarily as metabolites.
Renal: 50-70% (brompheniramine) as metabolites and unchanged drug; guaifenesin metabolites primarily renal; dextromethorphan and metabolites renal. Biliary/fecal: minor.
Ketorolac is highly protein bound, approximately 99% bound to plasma proteins, primarily albumin.
Brompheniramine: 50-60% to albumin; guaifenesin: <5%; dextromethorphan: 60-70% to albumin.
The volume of distribution is approximately 0.12 L/kg, indicating distribution primarily into extracellular fluid with limited tissue penetration.
Brompheniramine: 1.5-2.0 L/kg; guaifenesin: 0.5-1.0 L/kg; dextromethorphan: 5-10 L/kg.
Ophthalmic bioavailability is approximately 2% of the administered dose due to extensive nasolacrimal drainage and systemic absorption. Oral bioavailability of ketorolac is approximately 80-100%, but this route is not used for ophthalmic formulations.
Oral: brompheniramine 50-70%, guaifenesin 70-90%, dextromethorphan 40-60% (first-pass metabolism).
No dosage adjustment required for renal impairment
e GFR 30–59 m L/min: Administer with caution and reduce frequency to every 6 hours. e GFR <30 m L/min: Avoid use due to risk of accumulation of dextromethorphan and phenylephrine.
No dosage adjustment required for hepatic impairment but use with caution in severe hepatic disease due to potential for increased systemic exposure
Child-Pugh Class A: No adjustment. Child-Pugh Class B: Reduce dosing interval to every 8 hours; use with caution. Child-Pugh Class C: Contraindicated due to extensive first-pass metabolism.
Safety and efficacy in pediatric patients below 2 years of age have not been established; for children 2 years and older, same as adult dosing
Children 6–11 years: 5 m L (half the adult dose) of liquid formulation (brompheniramine 2 mg, dextromethorphan 5 mg, phenylephrine 5 mg per 5 m L) orally every 4 hours, max 4 doses/day. Children 2–5 years: 2.5 m L orally every 4 hours, max 4 doses/day. Children <2 years: Contraindicated.
No specific dose adjustment recommended; use with caution due to increased incidence of age-related ocular conditions
Age ≥65 years: Initiate at half the adult dose (e.g., one tablet every 8 hours) due to increased anticholinergic effects and risk of urinary retention, constipation, and dizziness. Avoid in frail elderly or those with cognitive impairment.
None
None.
Increased risk of bleeding and bleeding-related adverse events due to platelet inhibition,May prolong bleeding time,Cross-sensitivity with aspirin and other NSAIDs,Caution in patients with prior history of corneal epithelial defects or ocular surgery,Not for intraocular injection
Do not use with MAOIs or for 2 weeks after stopping MAOIs due to risk of serotonin syndrome (dextromethorphan).,Avoid use in patients with asthma, chronic bronchitis, emphysema, or persistent cough (may suppress cough reflex).,Use with caution in patients with glaucoma, prostatic hyperplasia, urinary retention, or hypertension (brompheniramine anticholinergic effects).,CNS depression risk: may cause drowsiness; avoid alcohol or other sedatives.
Hypersensitivity to ketorolac tromethamine or any component of the formulation,Patients with active peptic ulcer disease, recent GI bleeding, or perforation,Patients with advanced renal disease or at risk for renal failure,Patients with known history of asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs
Concurrent MAOI therapy or within 14 days,Neonates or premature infants (brompheniramine),Breastfeeding (may suppress lactation; dextromethorphan safety not established),Severe hypertension or coronary artery disease (brompheniramine may increase heart rate)
No known food interactions for ophthalmic ketorolac. However, maintain good hydration and nutrition to support corneal healing.
Avoid concurrent use of tyramine-rich foods (e.g., aged cheeses, cured meats, soy sauce, fermented foods) due to risk of hypertensive crisis with sympathomimetic (phenylephrine). Grapefruit juice may increase dextromethorphan levels; avoid large amounts.
Ketorolac tromethamine, the active ingredient in ACULAR LS, is a nonsteroidal anti-inflammatory drug (NSAID). In animal reproduction studies, administration of ketorolac during organogenesis resulted in increased embryofetal mortality, delayed ossification, and increased incidence of skeletal abnormalities at doses less than the maximum recommended human ophthalmic dose. However, systemic exposure following ocular administration is very low. NSAIDs are generally avoided during pregnancy, especially in the third trimester, due to the risk of premature closure of the ductus arteriosus and oligohydramnios. The risk is considered low for ophthalmic use but should be used only if clearly needed.
Dimetane-DX contains brompheniramine (antihistamine) and dextromethorphan (antitussive). First trimester: Limited human data; animal studies show no teratogenicity at therapeutic doses. Second and third trimesters: Avoid due to risk of neonatal respiratory depression, withdrawal symptoms, and anticholinergic effects. Dextromethorphan: No clear teratogenic risk, but avoid use. Overall: Contraindicated in pregnancy unless benefit outweighs risk.
It is not known whether ketorolac is excreted in human milk after ophthalmic administration. Systemic levels are low, and following oral administration, ketorolac is excreted in breast milk at low concentrations (M/P ratio approximately 0.37). Due to the potential for adverse effects on the nursing infant, caution should be exercised. The low systemic absorption likely poses minimal risk.
Brompheniramine may suppress lactation and cause irritability in infants. Dextromethorphan is excreted in breast milk in small amounts (M/P ratio not well defined). Use with caution; consider alternative therapy.
No dosing adjustments are necessary for ophthalmic use during pregnancy due to negligible systemic absorption. Standard dosing (1 drop in the affected eye(s) four times daily) is recommended. Systemic NSAIDs may require dose adjustment due to increased volume of distribution and renal changes, but this does not apply to topical ocular ketorolac.
No specific dose adjustments are recommended for Dimetane-DX in pregnancy due to limited data. However, increased plasma volume and altered drug metabolism may reduce efficacy; clinicians should consider lowest effective dose and shortest duration. Avoid near delivery.
ACULAR LS (ketorolac tromethamine ophthalmic solution 0.4%) is a nonsteroidal anti-inflammatory drug (NSAID) indicated for the reduction of ocular pain and photophobia following corneal refractive surgery. Use with caution in patients with known bleeding tendencies or those on anticoagulants due to increased risk of ocular bleeding. Avoid concurrent use with other NSAIDs or steroids to minimize corneal adverse effects. Monitor for corneal epithelial breakdown or delayed healing.
DIMETANE-DX combines brompheniramine (first-generation antihistamine), phenylephrine (decongestant), and dextromethorphan (antitussive). Avoid in hypertension, MAOI use, or asthma. Monitor for CNS depression and anticholinergic effects.
Do not touch the dropper tip to any surface to avoid contamination.,Remove contact lenses before instillation and wait at least 10 minutes before reinserting.,Use only in the affected eye(s) as prescribed; do not use for longer than directed.,Temporary stinging or burning may occur upon instillation.,Report any persistent pain, redness, or visual changes to your doctor immediately.,Avoid driving or operating machinery if vision is blurred after use.
Do not drive or operate machinery until you know how this medication affects you; it may cause drowsiness or dizziness.,Avoid alcohol and other sedatives; they increase sedation and CNS depression.,Do not exceed recommended dosage or use for more than 7 days for cough.,Stop use and consult a doctor if symptoms persist or worsen, or if you develop fever, rash, or persistent headache.,Inform your healthcare provider if you have high blood pressure, heart disease, glaucoma, or urinary retention.
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 ACULAR LS vs DIMETANE-DX, answered by our medical review team.
ACULAR LS is a NSAID Ophthalmic that works by Selective COX-2 inhibitor; inhibits prostaglandin synthesis, reducing ocular inflammation and pain.. DIMETANE-DX is a Antitussive Combination that works by Dimetane-DX contains brompheniramine (first-generation antihistamine) and dextromethorphan (NMDA receptor antagonist and sigma-1 agonist). Brompheniramine antagonizes histamine at H1 receptors, reducing allergic symptoms; dextromethorphan suppresses cough by acting on the cough center in the medulla oblongata via NMDA receptor antagonism and sigma-1 receptor activation.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ACULAR LS and DIMETANE-DX 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 ACULAR LS is: 1 drop in the affected eye(s) four times daily. The standard adult dose of DIMETANE-DX is: Adults and children ≥12 years: One tablet (brompheniramine 4 mg, dextromethorphan 10 mg, phenylephrine 10 mg) orally every 4 hours as needed, not to exceed 4 doses in 24 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 ACULAR LS and DIMETANE-DX 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. ACULAR LS is classified as Category C. Ketorolac tromethamine, the active ingredient in ACULAR LS, is a nonsteroidal anti-inflammatory drug (NSAID). In animal reproduction studies, administration of ketorolac during org. DIMETANE-DX is classified as Category C. Dimetane-DX contains brompheniramine (antihistamine) and dextromethorphan (antitussive). First trimester: Limited human data; animal studies show no teratogenicity at therapeutic d. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.