Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ACUVAIL vs ACTAHIST
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Ketorolac tromethamine, a nonsteroidal anti-inflammatory drug (NSAID), inhibits prostaglandin synthesis by blocking cyclooxygenase (COX-1 and COX-2) enzymes. This reduces ocular inflammation and pain.
Antihistamine; binds to histamine H1 receptors, blocking the effects of histamine; also exhibits anticholinergic and mild sedative properties.
Reduction of ocular pain and inflammation following cataract surgery,Treatment of ocular itching associated with seasonal allergic conjunctivitis
Symptomatic relief of allergic rhinitis,Urticaria,Off-label: motion sickness,Off-label: insomnia
1 drop in the affected eye 4 times daily.
1.34 mg (one capsule) orally twice daily.
Terminal elimination half-life is approximately 46 minutes in the aqueous humor following ocular administration in humans.
6.9 ± 1.7 hours in adults; prolonged to 12-18 hours in elderly or patients with hepatic impairment, requiring dosing interval adjustment.
Primarily hepatic via conjugation with glucuronic acid; minor role of cytochrome P450 enzymes. Approximately 50% is excreted as parent drug and metabolites in urine.
Hepatic metabolism via CYP450 enzymes (primarily CYP3A4 and CYP2D6); major metabolite is inactive.
Primarily renal excretion of metabolites; less than 1% excreted unchanged. Biliary/fecal elimination accounts for <10%.
Primarily renal (approximately 85% as unchanged drug and metabolites) and fecal (15%) via biliary elimination.
>99% bound to plasma proteins, primarily albumin.
92% bound to albumin.
Intravenous administration in animals suggests Vd ~0.15 L/kg, indicating limited distribution; clinically, it distributes into aqueous humor after topical dosing.
0.9 ± 0.3 L/kg, indicating extensive extravascular distribution.
Ocular bioavailability is dependent on formulation; systemic bioavailability after topical ocular administration is extremely low (<1%).
Oral: 68% ± 12% due to first-pass metabolism.
No adjustment required. Drug is minimally systemically absorbed.
No dose adjustment required for mild to moderate renal impairment. Safety not established for severe impairment (GFR <30 m L/min).
No adjustment required. Drug is minimally systemically absorbed.
No dose adjustment required for mild to moderate hepatic impairment (Child-Pugh A or B). Not recommended for severe hepatic impairment (Child-Pugh C).
Safety and efficacy in pediatric patients have not been established.
Not indicated for pediatric patients under 12 years of age. Safety and efficacy not established.
No specific dosage adjustment is recommended; use same dose as younger adults.
No specific dose adjustment recommended; monitor for increased anticholinergic effects and cognitive impairment.
No black box warning for ophthalmic use; however, systemic NSAIDs carry risk of serious cardiovascular and gastrointestinal events. Ophthalmic use rarely associated with corneal adverse events.
None.
Use with caution in patients with bleeding disorders or those on anticoagulants; may prolong bleeding time. Avoid in patients with known hypersensitivities to NSAIDs or aspirin. Can cause corneal keratopathy; discontinue if corneal epithelial breakdown occurs.
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.
Hypersensitivity to any component of the formulation. Active corneal epithelial defect. Patients with aspirin-sensitive asthma.
Hypersensitivity to any component. Newborns or premature infants. Breastfeeding (contraindicated due to risk of adverse effects in infants). Concomitant use with MAOIs.
No specific food interactions; systemic absorption is minimal with ophthalmic use. Avoid concurrent use of other NSAID eye drops due to additive irritation.
Avoid high-tyramine foods (aged cheese, cured meats, fermented products) if taking MAOIs. Grapefruit juice may increase phenylephrine absorption; limit intake.
Acuvail (ketorolac tromethamine ophthalmic solution) is classified as FDA Pregnancy Category C. Systemic exposure after ocular administration is minimal; however, NSAIDs may cause premature closure of the ductus arteriosus and oligohydramnios in the third trimester. Use during the first and second trimesters should be limited to cases where potential benefit outweighs risk; avoid during the third trimester due to risk of fetal harm.
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.
Ketorolac is excreted in human milk following systemic administration, but ocular doses produce negligible systemic levels. The M/P ratio is not determined for ophthalmic use. Use with caution in nursing mothers, as the clinical significance is likely low due to minimal systemic absorption.
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 dosage adjustment is required for ophthalmic use during pregnancy, as systemic exposure is negligible. However, avoid use in third trimester due to risks. Pharmacokinetic changes in pregnancy do not significantly alter ocular delivery.
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.
Acuvail (ketorolac tromethamine ophthalmic solution 0.45%) is a nonsteroidal anti-inflammatory drug (NSAID) for ocular use. It is preserved with sodium chloride and not benzalkonium chloride, reducing corneal epithelial toxicity. Administer 1 drop twice daily for ocular pain and inflammation following cataract surgery. Use caution in patients with bleeding tendencies or those on anticoagulants due to risk of increased ocular bleeding. Monitor for corneal epithelial defects and keratitis, especially with prolonged use.
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.
Wash hands before each use; do not touch tip of bottle to eye or any surface to avoid contamination.,Remove contact lenses before instillation and wait at least 15 minutes before reinserting.,Contact your doctor if you experience eye pain, redness, vision changes, or if symptoms worsen.,Do not use this medication while wearing contact lenses unless directed by your doctor.,Store at room temperature, keep bottle tightly closed when not in use, and discard within 28 days of opening.
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 ACUVAIL vs ACTAHIST, answered by our medical review team.
ACUVAIL is a NSAID Ophthalmic that works by Ketorolac tromethamine, a nonsteroidal anti-inflammatory drug (NSAID), inhibits prostaglandin synthesis by blocking cyclooxygenase (COX-1 and COX-2) enzymes. This reduces ocular inflammation and pain.. 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 ACUVAIL 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 ACUVAIL is: 1 drop in the affected eye 4 times daily.. 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 ACUVAIL 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. ACUVAIL is classified as Category C. Acuvail (ketorolac tromethamine ophthalmic solution) is classified as FDA Pregnancy Category C. Systemic exposure after ocular administration is minimal; however, NSAIDs may cause . 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.