Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ACTIQ vs AZOPT
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Opioid agonist; binds to mu-opioid receptors in the CNS, altering pain perception and response.
Carbonic anhydrase inhibitor; inhibits carbonic anhydrase II (CA-II) in ciliary processes, reducing aqueous humor secretion and intraocular pressure.
Management of breakthrough pain in cancer patients aged 16 and older who are already receiving and tolerant to opioid therapy for their underlying persistent cancer pain
Open-angle glaucoma,Ocular hypertension
200 mcg transmucosally, titrated upward as needed; initial dose for opioid-tolerant patients is 200 mcg, with additional doses possible after 15 minutes if needed. Maximum 4 doses per episode. At least 4 hours between episodes.
One drop in the affected eye(s) twice daily. Instill at least 10 minutes apart from other ophthalmic medications.
Terminal half-life 0.83–2 hours (mean 1.3 h) in adults; note that context: transmucosal absorption leads to rapid onset but short duration; half-life is not correlated with clinical effect due to oral transmucosal route and rapid redistribution.
Terminal elimination half-life is approximately 111 minutes (1.85 hours) in plasma after topical ocular administration; prolonged in renal impairment (creatinine clearance <30 m L/min).
Primarily hepatic via CYP3A4 to inactive metabolites (norfentanyl, despropionylfentanyl, hydroxyfentanyl) and other metabolites; <7% excreted unchanged in urine.
Not significantly metabolized; primarily excreted unchanged in urine via renal tubular secretion.
Primarily renal as metabolites (about 75% as metabolites, <10% unchanged). Fecal excretion accounts for <9%. Biliary excretion is minor.
Primarily renal excretion as unchanged drug (approximately 70% of a topically applied dose is absorbed systemically and excreted unchanged in urine); minimal biliary/fecal elimination (<5%).
Fentanyl is 80–85% bound to plasma proteins (primarily albumin and α1-acid glycoprotein).
Approximately 33% bound to plasma proteins (mainly albumin).
Approximately 4 L/kg (range 3–6 L/kg); large Vd indicates extensive tissue distribution and redistribution contributing to short duration.
Volume of distribution is approximately 0.35 L/kg, indicating distribution primarily into extracellular fluid.
Oral transmucosal: 50% (range 47–54%) relative to IV; variable and enhanced by rapid absorption through buccal mucosa.
Ocular bioavailability is not quantified due to local administration; systemic bioavailability after topical ocular dosing is approximately 70% via nasolacrimal absorption.
No specific GFR-based dose adjustment recommended; use with caution in severe renal impairment (Cr Cl < 30 m L/min) and consider dose reduction due to potential accumulation.
No dosage adjustment required for systemic absorption is minimal. However, use caution in severe renal impairment (Cr Cl <30 m L/min) due to potential metabolite accumulation.
Child-Pugh Class A/B: No adjustment. Child-Pugh Class C: Reduce initial dose to 100 mcg and titrate slowly; monitor closely for prolonged effects.
No dosage adjustment required for systemic absorption is minimal. Use caution in severe hepatic impairment (Child-Pugh class C) due to limited data.
Not approved for pediatric use; safety and efficacy not established in patients under 16 years.
Approved for children ≥2 years: one drop in the affected eye(s) twice daily. For children <2 years: safety and efficacy not established.
Initiate at 100 mcg transmucosally; titrate slowly due to increased sensitivity and risk of respiratory depression. Monitor for adverse effects.
No specific dose adjustment required. Monitor for ocular irritation and systemic effects, as elderly patients may be more sensitive to adverse reactions such as hypotension or fatigue.
Risk of respiratory depression, addiction, abuse, and misuse; accidental ingestion can be fatal; concomitant use with benzodiazepines or CNS depressants may cause profound sedation, respiratory depression, coma, and death; not for use in opioid non-tolerant patients; risk of neonatal opioid withdrawal syndrome with prolonged use during pregnancy; serious, life-threatening, or fatal respiratory depression may occur even at recommended doses.
None
Risk of respiratory depression; addiction, abuse, and misuse; interactions with CNS depressants; serotonin syndrome; adrenal insufficiency; severe hypotension; seizures; withdrawal; use in patients with head injuries, increased intracranial pressure, biliary tract disease, pancreatitis; risk of choking with lozenge; oral mucosal irritation; dental caries; hypokalemia; hyponatremia; use in elderly, cachectic, or debilitated patients.
Sulfonamide allergy (cross-reactivity possible),Corneal endothelial damage (risk increased with low endothelial cell count),Bacterial keratitis (with concomitant use of topical corticosteroids or ocular trauma),Contaminated dropper tip may cause ocular infections
Significant respiratory depression; acute or severe bronchial asthma in an unmonitored setting or without resuscitative equipment; known or suspected paralytic ileus; hypersensitivity to fentanyl or any component; opioid non-tolerant patients; management of acute or postoperative pain including headache/migraine, dental pain, or emergency department use.
Hypersensitivity to brinzolamide or any sulfonamides,Severe renal impairment (Cr Cl <30 m L/min) or hyperchloremic acidosis
No significant food interactions. Grapefruit juice may increase fentanyl levels, but specific studies with ACTIQ are lacking. Avoid alcohol, as it may increase sedation and respiratory depression risk.
No significant food interactions known. However, avoid excessive salt intake if using systemic carbonic anhydrase inhibitors; for AZOPT, ocular use minimizes systemic effects, but caution in patients with electrolyte imbalances.
FDA Pregnancy Category C. First trimester: limited human data; animal studies show increased resorptions and fetal growth restriction. Second/third trimester: chronic use may cause neonatal opioid withdrawal syndrome; avoid use during labor due to risk of neonatal respiratory depression.
Pregnancy Category C. No adequate studies in pregnant women. In animal studies, brinzolamide (active ingredient) showed no teratogenic effects at oral doses up to 6 mg/kg/day in rabbits and 20 mg/kg/day in rats. However, due to potential for fetal harm (systemic carbonic anhydrase inhibition causing acidosis), use only if clearly needed. First trimester: avoid if possible; second/third trimesters: monitor for maternal acidosis.
Excreted in breast milk; M/P ratio not established. Limited data suggest low levels, but risk of infant sedation and respiratory depression. Avoid use while breastfeeding unless potential benefit outweighs risk.
It is not known if brinzolamide is excreted in human milk. In animal studies, brinzolamide was detected in milk of lactating rats. Caution is advised; consider risk vs benefit. M/P ratio: unknown.
Due to increased plasma volume and hepatic metabolism in pregnancy, dose requirements may increase; adjust based on clinical response and tolerance. Avoid use during labor and delivery due to risk of neonatal respiratory depression; short-term use preferred.
No specific dose adjustments recommended; however, due to potential for increased systemic absorption during pregnancy (increased blood volume and ocular changes), monitor intraocular pressure closely. Use the lowest effective dose. Pharmacokinetic changes: unknown; adjust based on clinical response.
ACTIQ is a transmucosal immediate-release fentanyl formulation indicated for breakthrough cancer pain in opioid-tolerant patients. Initiate with the lowest strength (200 mcg) and titrate upward. Avoid use in opioid-naive patients due to risk of fatal respiratory depression. Place the unit between cheek and lower gum, not sublingually. Instruct patient not to bite or suck the unit. Monitor for sedation and respiratory depression. Multiple units may be used per episode if needed, but wait at least 4 hours before next episode. Dispose of partially used units by flushing down toilet.
AZOPT (brinzolamide ophthalmic suspension) is a carbonic anhydrase inhibitor used for lowering intraocular pressure in ocular hypertension or open-angle glaucoma. Shake well before use; may cause transient blurred vision. Use with caution in sulfonamide allergy patients. Monitor for corneal edema and electrolyte disturbances in prolonged use.
Only use ACTIQ if you are already taking regular around-the-clock opioid pain medicine and are tolerant to opioids.,Do not use ACTIQ for short-term pain like after surgery, headache, or dental pain.,Place the unit in your cheek pouch, not under your tongue. Do not chew or suck it.,If you need more than 4 units per day, contact your doctor as your dose may need adjustment.,Store ACTIQ in a safe place away from children, as accidental ingestion can be fatal.,Dispose of unused or partially used units by flushing them down the toilet.
Shake the bottle vigorously before each use.,Remove contact lenses before instilling and wait at least 15 minutes before reinserting.,Apply pressure to the tear duct (punctal occlusion) for 1 minute after instillation to reduce systemic absorption.,Do not touch the dropper tip to any surface to avoid contamination.,May cause temporary blurred vision; avoid driving or operating machinery until vision clears.,Report any eye pain, redness, or vision changes to your healthcare provider.
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 ACTIQ vs AZOPT, answered by our medical review team.
ACTIQ is a Opioid Analgesic that works by Opioid agonist; binds to mu-opioid receptors in the CNS, altering pain perception and response.. AZOPT is a Carbonic Anhydrase Inhibitor that works by Carbonic anhydrase inhibitor; inhibits carbonic anhydrase II (CA-II) in ciliary processes, reducing aqueous humor secretion and intraocular pressure.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ACTIQ and AZOPT 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 ACTIQ is: 200 mcg transmucosally, titrated upward as needed; initial dose for opioid-tolerant patients is 200 mcg, with additional doses possible after 15 minutes if needed. Maximum 4 doses per episode. At least 4 hours between episodes.. The standard adult dose of AZOPT is: One drop in the affected eye(s) twice daily. Instill at least 10 minutes apart from other ophthalmic medications.. 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 ACTIQ and AZOPT 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. ACTIQ is classified as Category C. FDA Pregnancy Category C. First trimester: limited human data; animal studies show increased resorptions and fetal growth restriction. Second/third trimester: chronic use may cause. AZOPT is classified as Category C. Pregnancy Category C. No adequate studies in pregnant women. In animal studies, brinzolamide (active ingredient) showed no teratogenic effects at oral doses up to 6 mg/kg/day in ra. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.