Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ACULAR vs AMMONIUM CHLORIDE 2.14%
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin synthesis, which decreases inflammation, pain, and fever.
Ammonium chloride is an acidifying agent. It dissociates into ammonium and chloride ions. The ammonium ion is metabolized in the liver to urea and hydrogen ions, leading to metabolic acidosis. This reduces blood p H and increases renal excretion of alkaline urine.
Treatment of postoperative inflammation in patients who have undergone cataract extraction,Relief of ocular itching due to seasonal allergic conjunctivitis
Treatment of metabolic alkalosis,Urinary acidification to enhance excretion of weak bases (e.g., amphetamines, quinidine) or to promote dissolution of calcium phosphate stones
One drop of 0.5% ophthalmic solution into the affected eye(s) four times daily.
For metabolic alkalosis: 1.5 to 3 g (approximately 280 to 560 m Eq) intravenously over 4 to 6 hours; adjust based on serum chloride and p H.
Terminal half-life: 1.8 hours (ketorolac tromethamine); clinical context: short half-life supports dosing every 6 hours for acute pain, but prolonged in elderly or renal impairment (↑ to 5-6 hours, thus dose reduction required).
4-6 hours; prolonged in renal impairment (up to 12-15 hours).
Hepatic metabolism primarily via cytochrome P450 2C9 (CYP2C9).
Converted to urea and hydrogen ions in the liver via the urea cycle.
Renal: ~80% as unchanged drug and glucuronide conjugates; biliary/fecal: ~20%
Renal: >99% as ammonium ion and chloride; minimal biliary/fecal elimination.
99% bound; primary binding protein: albumin.
Negligible (<1%); not significantly bound to plasma proteins.
0.11-0.25 L/kg; clinical meaning: low Vd indicates primarily confined to extracellular compartment (plasma and interstitial fluid), minimal tissue penetration.
0.3-0.5 L/kg; distributes primarily in extracellular fluid; clinical meaning: low Vd reflects limited tissue penetration.
Ophthalmic: ~2% systemic absorption after topical instillation (due to corneal permeability and nasolacrimal drainage); oral formulation not used for Acular (ophthalmic only).
Oral: 100% (fully absorbed); IV: 100%; topical: non-systemic.
No dosage adjustment required for renal impairment.
Contraindicated in severe renal impairment (GFR <30 m L/min). For GFR 30-60 m L/min: reduce dose by 50% and monitor serum electrolytes. For GFR >60 m L/min: no adjustment.
No dosage adjustment required for hepatic impairment.
No specific Child-Pugh based adjustment; use caution in severe hepatic impairment due to risk of ammonia toxicity.
Safety and efficacy in pediatric patients have not been established; use not recommended.
Neonates and children: 1-2 m Eq/kg intravenously per dose, infused over 2-4 hours; maximum 100 m Eq per dose. Titrate based on serum chloride and acid-base status.
No specific dosage adjustment required; use same dosing as for younger adults.
Start at lower end of adult dosing (e.g., 1.5 g intravenously) due to age-related decreased renal function; monitor electrolytes and renal function closely.
No FDA boxed warning.
None
May increase bleeding time due to inhibition of platelet aggregation; use with caution in patients with known bleeding tendencies or those receiving other medications that may prolong bleeding time.,May cause corneal effects including keratitis and corneal thinning; discontinue if corneal epithelial breakdown occurs.,Use with caution in patients with prior sensitivity to aspirin, phenylacetic acid derivatives, or other NSAIDs.,May delay wound healing or exacerbate infections; avoid use in patients with active epithelial herpes simplex keratitis.
Avoid in patients with impaired renal or hepatic function; may cause hyperammonemia and hepatic coma.,Use with caution in patients with cardiac failure or pulmonary edema due to risk of fluid overload.,Monitor serum chloride, bicarbonate, and p H levels during therapy.
Hypersensitivity to ketorolac tromethamine or any component of the formulation,History of asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs,Active epithelial herpes simplex keratitis,Late pregnancy (third trimester) due to risk of premature closure of ductus arteriosus
Severe hepatic insufficiency,Severe renal impairment,Hyperammonemia,Uremia,Ammonium toxicity
No known food interactions. Avoid alcohol if concomitant oral NSAIDs are used due to increased risk of gastrointestinal bleeding, but this is not specific to ophthalmic use.
No significant food interactions known. However, a diet low in chloride may reduce efficacy. Avoid excessive intake of alkalinizing foods (e.g., citrus fruits, vegetables) that may counteract the acidifying effect.
Pregnancy Category C. No adequate studies in pregnant women. Ketorolac tromethamine, like other NSAIDs, may cause premature closure of the ductus arteriosus and fetal renal impairment in the third trimester. First and second trimester use should be avoided unless clearly needed. The potential benefits should be weighed against the risks.
Ammonium chloride is not known to be teratogenic in humans. No structural anomalies have been reported with first trimester exposure. In second and third trimesters, maternal acidosis from excessive dosing could potentially affect fetal acid-base balance, but no specific fetal risks are documented. Overall, classified as FDA Pregnancy Category C.
Ketorolac is excreted in human milk at low levels. The M/P ratio is not well defined. Due to potential adverse effects in nursing infants, caution is advised. Use only if clearly indicated and consider alternative agents.
Excretion into breast milk is unknown. M/P ratio not available. Caution advised due to potential for neonatal acidosis if maternal doses are high. Short-term use is likely compatible with breastfeeding.
No specific dose adjustments are recommended for pregnancy; however, use the lowest effective dose for the shortest duration due to potential fetal risks. Physiological changes in pregnancy (increased volume of distribution, renal clearance) may alter pharmacokinetics, but no formal studies justify dose modification.
No specific dosing adjustments required in pregnancy. However, due to pregnancy-associated hyperventilation and renal changes, monitor acid-base status. Initiate at low doses and titrate based on serum chloride and bicarbonate levels.
ACULAR (ketorolac tromethamine ophthalmic solution) is a nonsteroidal anti-inflammatory drug (NSAID) used for ocular inflammation. Avoid concomitant use with other NSAIDs or corticosteroids due to increased risk of corneal adverse events. Use with caution in patients with bleeding disorders or those on anticoagulants, as it may increase bleeding tendency. Monitor for corneal toxicity, especially in patients with compromised corneal integrity. Ensure proper storage at room temperature and discard if solution changes color or becomes cloudy.
Ammonium chloride 2.14% is a systemic acidifying agent used to treat metabolic alkalosis. Monitor serum electrolytes (especially chloride and bicarbonate) and arterial blood gases closely. Avoid in patients with severe hepatic or renal impairment, as ammonium ions can precipitate hepatic encephalopathy or worsen acidosis. Infuse slowly to prevent hemolysis. Use with caution in patients with respiratory acidosis.
Do not touch the dropper tip to any surface to avoid contamination.,Remove contact lenses before instillation and wait at least 15 minutes before reinserting.,Apply pressure to the inner corner of the eye (nasolacrimal occlusion) for 1 minute after instillation to reduce systemic absorption.,Do not use while wearing soft contact lenses, as the preservative may be absorbed.,Report any signs of corneal problems such as pain, redness, or vision changes immediately.,Use exactly as prescribed and do not share the medication with others.
This medication is used to treat low acid levels in the blood.,Your healthcare provider will monitor your blood tests regularly while on this medicine.,Report any signs of allergic reaction (rash, itching, swelling) or symptoms of acidosis (confusion, rapid breathing) immediately.,Avoid taking other medications or supplements without consulting your doctor, as they may interfere with this treatment.,Do not stop this medication abruptly without medical advice.
No interactions on record
"Ammonium chloride, an acidifying agent, reduces urinary pH, which increases the renal clearance of lisdexamfetamine and its active metabolite d-amphetamine. This accelerated elimination leads to decreased systemic exposure and potentially diminished therapeutic efficacy of lisdexamfetamine. Clinically, patients may experience reduced symptom control for ADHD or binge eating disorder, requiring dose adjustments or alternative therapies."
"Sufentanil, a potent opioid analgesic, may increase renal excretion of ammonium chloride by promoting diuresis through opioid-induced release of antidiuretic hormone (ADH) and subsequent water reabsorption, leading to dilutional acidosis and enhanced ammonium excretion. This interaction can result in reduced serum ammonium levels and decreased efficacy of ammonium chloride as an acidifying agent, potentially compromising its therapeutic effect in metabolic alkalosis or urinary tract infections. Clinical outcomes may include incomplete correction of metabolic alkalosis or reduced antimicrobial activity of ammonium chloride in the urine."
"Ammonium chloride acidifies the urine, which increases the renal excretion of amphetamine by favoring its ionized form in the tubular lumen, thereby reducing its reabsorption. This leads to a decreased serum concentration of amphetamine and potentially diminished therapeutic efficacy. Clinically, patients may experience reduced mood-elevating or stimulant effects, requiring dose adjustment."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ACULAR vs AMMONIUM CHLORIDE 2.14%, answered by our medical review team.
ACULAR is a NSAID Ophthalmic that works by Nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin synthesis, which decreases inflammation, pain, and fever.. AMMONIUM CHLORIDE 2.14% is a Expectorant/Systemic Acidifier that works by Ammonium chloride is an acidifying agent. It dissociates into ammonium and chloride ions. The ammonium ion is metabolized in the liver to urea and hydrogen ions, leading to metabolic acidosis. This reduces blood p H and increases renal excretion of alkaline urine.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ACULAR and AMMONIUM CHLORIDE 2.14% 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 is: One drop of 0.5% ophthalmic solution into the affected eye(s) four times daily.. The standard adult dose of AMMONIUM CHLORIDE 2.14% is: For metabolic alkalosis: 1.5 to 3 g (approximately 280 to 560 m Eq) intravenously over 4 to 6 hours; adjust based on serum chloride and p H.. 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 and AMMONIUM CHLORIDE 2.14% 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 is classified as Category C. Pregnancy Category C. No adequate studies in pregnant women. Ketorolac tromethamine, like other NSAIDs, may cause premature closure of the ductus arteriosus and fetal renal impairm. AMMONIUM CHLORIDE 2.14% is classified as Category C. Ammonium chloride is not known to be teratogenic in humans. No structural anomalies have been reported with first trimester exposure. In second and third trimesters, maternal acido. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.