Drug Monograph

Spravato (Esketamine Nasal Spray)

esketamine hydrochloride

NMDA Receptor Antagonist · Intranasal · Schedule III (CIII)
Pharmacokinetic Profile
Half-Life
7–12 h
Metabolism
Hepatic (CYP2B6, CYP3A4)
Protein Binding
43–45%
Bioavailability
~48% (intranasal)
Volume of Distribution
~752 L (Vss)
Clinical Information
Drug Class
NMDA Receptor Antagonist
Available Doses
28 mg per device (56 mg or 84 mg per session)
Route
Intranasal only
Renal Adjustment
None required (no dialysis data)
Hepatic Adjustment
Monitor longer in moderate; not studied in severe
Pregnancy
Not recommended (fetal harm)
Lactation
Breastfeeding not recommended
Schedule
Schedule III (REMS required)
Generic Available
No
Black Box Warning
Yes — Sedation, Dissociation, Respiratory Depression, Abuse/Misuse, Suicidality
Rx

Indications

IndicationApproved PopulationTherapy TypeStatus
Treatment-resistant depression (TRD)Adults (≥18 years)Monotherapy or adjunctive to oral antidepressantFDA Approved
MDD with acute suicidal ideation or behavior (MDD-SI)Adults (≥18 years)Adjunctive to oral antidepressantFDA Approved

Esketamine nasal spray was first approved by the FDA in March 2019 for treatment-resistant depression in conjunction with an oral antidepressant. The indication for depressive symptoms in adults with MDD and acute suicidal ideation or behavior was added in July 2020. In January 2025, the FDA approved a supplemental application allowing esketamine to be used as monotherapy for TRD, without the requirement for a concomitant oral antidepressant. TRD is defined as an inadequate response to at least two oral antidepressants of adequate dose and duration in the current episode. Esketamine is available only through a restricted REMS program requiring administration in a certified healthcare setting with post-dose monitoring.

Off-Label Uses

Acute pain management (emergency settings): Emerging evidence supports sub-anesthetic esketamine for procedural and trauma-related pain in emergency departments. Evidence quality: Low (case series and small RCTs).

Bipolar depression: Limited data from small open-label studies suggest potential benefit; however, risk of mood switching has not been adequately characterised. Evidence quality: Very low.

Dose

Dosing

Treatment-Resistant Depression — Adults

Clinical ScenarioStarting DoseMaintenance DoseMaximum DoseNotes
TRD induction (Weeks 1–4)56 mg or 84 mg twice weekly56 or 84 mg twice weekly84 mg twice weeklyEither dose may be used from Day 1; adjust based on efficacy and tolerability; evaluate at end of Week 4 for continuation
Each 28 mg device = 2 sprays (1 per nostril); 56 mg = 2 devices, 84 mg = 3 devices
TRD early maintenance (Weeks 5–8)56 or 84 mg once weekly56 or 84 mg once weekly84 mg once weeklyReduce frequency from induction; dose adjustments guided by response
TRD extended maintenance (Week 9+)56 or 84 mg every 1–2 weeks56 or 84 mg every 1–2 weeks84 mg once weeklyIndividualize to least frequent dosing that maintains remission/response

MDD with Acute Suicidal Ideation or Behavior — Adults

Clinical ScenarioStarting DoseMaintenance DoseMaximum DoseNotes
MDD-SI acute phase (4 weeks)84 mg twice weekly84 mg twice weekly84 mg twice weeklyMust be given with an oral antidepressant; one-time dose reduction to 56 mg permitted for tolerability
Treatment beyond 4 weeks has not been systematically evaluated for this indication

Special Populations

Clinical ScenarioStarting DoseMaintenance DoseMaximum DoseNotes
Moderate hepatic impairment (Child-Pugh B)56 mg56 or 84 mg84 mgEsketamine AUC ~103% higher; monitor for adverse reactions for a longer period
No dose adjustment recommended, but extended post-dose monitoring warranted
Severe hepatic impairment (Child-Pugh C)Not studiedAvoid use; no clinical data available
Renal impairment (any severity)Standard dosingStandard dosing84 mg<1% excreted unchanged in urine; no adjustment needed. No data in patients on dialysis
Elderly (≥65 years)56 or 84 mg twice weekly56 or 84 mg84 mgSame dosing as younger adults per FDA PI. TRANSFORM-3 trial used a 28 mg starting dose on Day 1 before uptitrating. Clinical judgement may favour conservative initiation. Hepatic blood flow declines with age, potentially prolonging exposure
Clinical Pearl: Administration Logistics

A 56 mg dose requires 2 devices and an 84 mg dose requires 3 devices, each with a 5-minute rest between devices. Patients should avoid food for at least 2 hours and liquids for at least 30 minutes before dosing. Nasal corticosteroids or decongestants used on a dosing day should be given at least 1 hour beforehand. Do not prime the device before use to prevent medication loss.

PK

Pharmacology

Mechanism of Action

Esketamine is the S-enantiomer of racemic ketamine and functions as a non-competitive antagonist at the N-methyl-D-aspartate (NMDA) receptor. It possesses approximately four-fold higher affinity for the NMDA receptor compared to the R-enantiomer (arketamine). By blocking NMDA receptors on inhibitory GABAergic interneurons in cortical circuits, esketamine transiently disinhibits glutamate release. The resulting surge of glutamate activates postsynaptic AMPA receptors, triggering downstream signalling cascades involving brain-derived neurotrophic factor (BDNF), tropomyosin receptor kinase B (TrkB), and mammalian target of rapamycin complex 1 (mTORC1). These pathways promote rapid synaptogenesis and restoration of synaptic connectivity in prefrontal and limbic mood-regulating circuits. This mechanism is fundamentally distinct from conventional monoaminergic antidepressants and is believed to underlie the rapid onset of antidepressant effect observed within 24 hours of administration. The precise mechanism by which NMDA antagonism translates into sustained mood improvement remains an area of active investigation.

ADME Profile

ParameterValueClinical Implication
AbsorptionTmax 20–40 min after last nasal spray; bioavailability ~48% (intranasal); ~54% of dose absorbed via nasal mucosa, remainder swallowedRapid absorption enables onset of dissociative and antidepressant effects within minutes; nasal congestion may alter absorption
DistributionVss ~752 L; protein binding 43–45% (albumin and alpha-1 acid glycoprotein)Large volume of distribution indicates extensive tissue penetration including CNS; low protein binding means minimal displacement interactions
MetabolismHepatic N-demethylation to noresketamine (active) primarily via CYP2B6 and CYP3A4; further metabolism to hydroxynorketamines and dehydronorketamineNoresketamine has lower NMDA affinity than parent drug; hepatic impairment doubles esketamine AUC; CYP inducers/inhibitors have modest clinical impact due to high hepatic extraction
Eliminationt½ 7–12 h; <1% excreted unchanged in urine; metabolites primarily renal (≥78%)No accumulation with twice-weekly dosing; renal impairment does not significantly affect parent drug clearance
SE

Side Effects

The adverse reaction profile of esketamine is dominated by acute, transient effects related to its NMDA receptor antagonism. Most events peak within 40 minutes of dosing and resolve within 1.5 hours. Data below are from pooled short-term Phase 3 TRD trials (esketamine + oral AD vs placebo nasal spray + oral AD, N=346 vs N=222) per the FDA prescribing information.

≥10% Very Common
Adverse EffectIncidenceClinical Note
Dissociation41%Includes depersonalisation, derealisation, perceptual changes, visual disturbances; typically resolves within 1.5 h; 61–84% of patients experience dissociative symptoms on CADSS scale
Dizziness29%Includes postural dizziness; advise patients to remain seated/reclined during observation period
Nausea28%Dose-related; fasting 2 h pre-dose reduces incidence; anti-emetics may be given if recurrent
Sedation23%Includes somnolence and hypersomnia; 48–61% show sedation on MOAA/S scale; 0.3–0.4% experience loss of consciousness
Vertigo23%Includes positional vertigo; patients should not stand unassisted until stable
Headache20%Including sinus headache; similar in severity to placebo group (17%)
Dysgeusia19%Metallic or unpleasant taste; transient; related to post-nasal drainage of medication
Hypoesthesia18%Oral and pharyngeal numbness from local NMDA receptor blockade in nasal/oral mucosa
Anxiety13%Includes agitation, panic attacks, nervousness, irritability; may require clinical reassurance during observation
Lethargy11%Includes fatigue; dose-related; generally resolves within 2 h of dosing
Blood pressure increased10%BP peaks at ~40 min (Tmax); resolves by ~4 h; 3–19% have ≥40 mmHg SBP or ≥25 mmHg DBP rise
1–10% Common
Adverse EffectIncidenceClinical Note
Vomiting9%Usually accompanies nausea; pre-treatment with ondansetron may help in susceptible patients
Insomnia8%May persist beyond acute dosing session; monitor sleep quality
Nasal discomfort7%Includes nasal dryness, crusting, and pruritus; generally mild
Throat irritation7%Related to post-nasal drainage of the drug solution
Diarrhoea7%Similar incidence to placebo (6%); usually mild
Feeling drunk5%Patients often describe a sensation of intoxication; part of the dissociative spectrum
Dry mouth5%Anticholinergic-type effect; may compound if patient is on tricyclics
Euphoric mood4%Contributes to abuse potential; important to document and monitor
Dysarthria4%Slurred or slowed speech; resolves during observation period
Hyperhidrosis4%Autonomic effect; transient
Pollakiuria3%Urinary frequency; monitor for persistent bladder symptoms over long-term treatment
Tremor3%Transient; distinguish from lithium or valproate co-medication effects
Tachycardia2%Sympathomimetic effect; monitor with BP assessment
Serious Serious (Regardless of Frequency)
Adverse EffectEstimated FrequencyTypical OnsetRequired Action
Respiratory depression / arrestRare (postmarketing)Minutes to 1 h post-doseContinuous pulse oximetry for 2 h post-dose; airway management equipment must be available; discontinue if respiratory arrest occurs
Loss of consciousness0.3–0.4%Within 40 min of dosingMOAA/S score of 0; ensure patent airway; do not discharge until fully alert; consider dose reduction at next session
Hypertensive crisisRare~40 min post-dose (at Tmax)Emergency referral if SBP >180 or DBP >120 with end-organ symptoms (chest pain, visual changes, seizure); IV antihypertensives as indicated
Suicidal ideation (worsening)0.5% (led to discontinuation)Any time during treatmentAssess suicidality at each visit; consider discontinuation and hospitalisation if clinically warranted; class-effect with antidepressants in patients <25 years
Ulcerative / interstitial cystitisRare (reported with ketamine misuse; no confirmed cases in clinical trials up to 1 year)Months of repeated exposureMonitor for dysuria, urgency, haematuria; refer to urology if symptoms develop; consider discontinuation
Severe dissociative reaction / psychosis-like symptomsRareWithin 1 h post-doseObserve in a calm environment; benzodiazepine if severe agitation; carefully reassess risk-benefit before further dosing in patients with psychosis history
DC Discontinuation Rates
TRD (with oral AD) — Short-term
4.6% vs 1.4% placebo
Top reasons: Anxiety (1.2%), depression (0.9%), BP increased (0.6%), dizziness (0.6%), suicidal ideation (0.5%)
MDD-SI — Short-term
6.2% vs 3.6% placebo
Top reasons: Dissociation (2.6%), BP increased (0.9%), dizziness (0.9%), nausea (0.9%), sedation (0.9%)
Reason for DiscontinuationIncidenceContext
Anxiety1.2%Most common reason across TRD Phase 3 trials
Depression (worsening)0.9%May represent non-response rather than drug-induced worsening
Blood pressure increased0.6%More common in patients with pre-existing hypertension
Dizziness0.6%Severe or prolonged dizziness prompting treatment cessation
Suicidal ideation0.5%Requires careful assessment to distinguish from underlying illness
Dissociation0.4%Despite being the most common adverse event, rarely leads to discontinuation in TRD; higher discontinuation rate (2.6%) in MDD-SI trials
Managing Blood Pressure Elevations

Blood pressure peaks approximately 40 minutes post-dose, coinciding with esketamine Tmax, and generally returns toward pre-dose levels over approximately 4 hours. In clinical trials, 3–19% of esketamine-treated patients experienced a clinically significant rise (≥40 mmHg SBP or ≥25 mmHg DBP). Pre-dose BP should be checked at every session, and dosing should be deferred if baseline values exceed 140/90 mmHg unless the benefit clearly outweighs the risk. BP is reassessed at ~40 minutes and as clinically needed until stable. Patients with a history of hypertensive encephalopathy require more frequent and intensive monitoring.

Int

Drug Interactions

Esketamine is metabolised primarily by CYP2B6 and CYP3A4. Despite this, dose adjustment is not routinely required with CYP inhibitors or inducers because esketamine undergoes high hepatic extraction and has a short pharmacodynamic window. The most clinically relevant interactions are pharmacodynamic, involving additive CNS depression or sympathomimetic blood pressure effects.

Major CNS Depressants (benzodiazepines, opioids, alcohol)
MechanismAdditive CNS and respiratory depression
EffectIncreased risk of profound sedation, loss of consciousness, and respiratory depression
ManagementClosely monitor sedation and respiratory status; consider dose or timing adjustment of the CNS depressant; alcohol must be avoided on dosing days
FDA PI
Major MAOIs (phenelzine, tranylcypromine, selegiline patch)
MechanismAdditive sympathomimetic effect on blood pressure via norepinephrine potentiation
EffectExaggerated hypertensive response; increased risk of hypertensive crisis
ManagementMonitor BP more frequently (consider q15min for first hour); have IV antihypertensives available; use with extreme caution
FDA PI
Moderate Psychostimulants (amphetamines, methylphenidate)
MechanismAdditive sympathomimetic cardiovascular effects
EffectGreater increase in blood pressure and heart rate
ManagementClose BP monitoring at each esketamine session; consider withholding stimulant dose on the morning of treatment
FDA PI
Moderate CYP3A4 Inducers (rifampin, carbamazepine, St. John’s Wort)
MechanismIncreased hepatic metabolism of esketamine via CYP3A4 induction
EffectPotentially reduced esketamine efficacy due to lower exposure
ManagementNo formal dose adjustment per FDA PI, but monitor for diminished antidepressant response; consider alternative mood stabiliser if on carbamazepine
FDA PI / Lexicomp
Minor CYP2B6/CYP3A4 Inhibitors (ticlopidine, fluvoxamine, ketoconazole)
MechanismReduced metabolism of esketamine
EffectModestly increased esketamine exposure
ManagementNo dose adjustment warranted per FDA PI; monitor for increased adverse effects (dissociation, sedation) during concurrent use
FDA PI
Minor Nasal Corticosteroids / Decongestants
MechanismLocal nasal effects may alter mucosal absorption of esketamine
EffectDecongestants (oxymetazoline) did not significantly affect esketamine exposure in PK studies; nasal steroids showed no clinically meaningful effect
ManagementAdminister nasal corticosteroids or decongestants at least 1 hour before esketamine
FDA PI
False-Positive Drug Screens

Esketamine can produce false-positive results for methadone and phencyclidine (PCP) on urine immunoassay drug screens. If a positive result is obtained, confirmatory testing with gas chromatography-mass spectrometry (GC-MS) is recommended before clinical decisions are made.

Mon

Monitoring

  • Blood Pressure Pre-dose, ~40 min post-dose, then PRN
    Routine
    Measure before every session to assess safety of dosing. Reassess at approximately 40 minutes (peak BP effect) and continue until values are declining and clinically stable. Do not discharge until BP is trending toward baseline.
  • Sedation Level Continuously for ≥2 h post-dose
    Routine
    Use MOAA/S or equivalent sedation scale. Patient must not leave the healthcare setting until clinically stable and alert. Assess readiness to leave before discharge at each session.
  • Respiratory Status Pulse oximetry for ≥2 h post-dose
    Routine
    Monitor oxygen saturation continuously during and after each treatment session. Airway management equipment should be readily accessible. Particular vigilance when patient is also on CNS depressants.
  • Dissociative Symptoms Each session during observation
    Routine
    Assess using CADSS or clinical observation. Symptoms typically peak within 40 minutes and resolve by 1.5 hours. Patients with psychosis history require particularly careful monitoring.
  • Suicidality At initiation, each session, and dose changes
    Routine
    Monitor for emergence or worsening of suicidal thoughts and behaviours, especially in patients <25 years. Consider discontinuation and hospitalisation if clinically indicated. Document at every visit per REMS requirements.
  • Urinary Symptoms Periodic inquiry
    Trigger-based
    Ask about dysuria, urgency, frequency, nocturia, or haematuria at each visit. Ketamine-related cystitis is associated with chronic use; esketamine-related cystitis has not been confirmed in trials up to 1 year but theoretical risk remains with long-term use. Refer to urology if symptoms develop.
  • Substance Use Baseline and ongoing
    Routine
    Assess risk of abuse and misuse prior to initiation. Monitor for drug-seeking behaviour, dose requests, and signs of ketamine diversion throughout treatment. Schedule III controlled substance with documented abuse potential.
  • Cognitive Function Annually or PRN
    Trigger-based
    Long-term cognitive effects were stable in 1- and 3-year open-label clinical trials. However, cognitive impairment is reported with repeated ketamine misuse. Assess if subjective complaints arise.
CI

Contraindications & Cautions

Absolute Contraindications

  • Aneurysmal vascular disease — including thoracic aorta, abdominal aorta, intracranial, and peripheral arterial aneurysms
  • Arteriovenous malformation — risk of catastrophic haemorrhage from acute BP elevation
  • History of intracerebral haemorrhage — BP spikes may precipitate re-bleeding
  • Hypersensitivity — to esketamine, ketamine, or any excipient in the formulation

Relative Contraindications (Specialist Input Recommended)

  • Active psychotic disorder — esketamine can induce or exacerbate psychosis-like dissociative symptoms; initiate only if benefit outweighs risk following specialist assessment
  • Unstable cardiovascular disease — uncontrolled hypertension, recent MI, unstable angina, or decompensated heart failure; transient BP elevations are expected
  • Active substance use disorder — high risk of misuse given Schedule III classification; requires documented risk-benefit discussion and enhanced monitoring
  • Pregnancy — animal data with ketamine show neuronal apoptosis and skeletal malformations; discontinue if patient becomes pregnant

Use with Caution

  • Moderate hepatic impairment (Child-Pugh B) — esketamine AUC approximately doubles; extend post-dose monitoring duration
  • Elderly patients (≥65 years) — reduced hepatic blood flow may prolong exposure; consider conservative dose selection and extended monitoring
  • Concurrent CNS depressant use — additive sedation and respiratory depression risk
  • History of hypertensive encephalopathy — even small BP increases may trigger encephalopathy; more intensive BP and symptom monitoring warranted
  • History of traumatic brain injury or raised intracranial pressure — ketamine has historically been considered a concern in this setting, although evidence is evolving
FDA Boxed Warning Sedation, Dissociation, Respiratory Depression, Abuse and Misuse, and Suicidal Thoughts and Behaviors

Patients are at risk for sedation (including loss of consciousness), dissociative or perceptual changes, and respiratory depression following esketamine administration. Patients must be monitored for at least 2 hours after each dose in a certified healthcare setting. Esketamine has the potential for abuse and misuse; assess each patient’s risk before prescribing. Because of these risks, esketamine is available only through a restricted REMS program. Antidepressants, including esketamine, increase the risk of suicidal thoughts and behaviours in patients under 25 years of age.

Pt

Patient Counselling

Purpose of Therapy

Esketamine nasal spray is prescribed for depression that has not responded adequately to other antidepressant medications. It works differently from standard antidepressants by acting on the glutamate system in the brain, which may help restore connections between nerve cells involved in mood regulation. Some patients notice improvement within hours to days, though full response may take several weeks of treatment. For the suicidal ideation indication, it is used alongside an oral antidepressant to provide rapid relief of depressive symptoms during a crisis period.

How to Take

Esketamine is administered as a nasal spray at a certified clinic or healthcare setting — it cannot be taken home. Each treatment session involves spraying the medication into both nostrils using one, two, or three devices depending on the prescribed dose. You will need to stay at the clinic for at least 2 hours after each dose so the healthcare team can monitor your blood pressure, alertness, and overall state. Do not eat for at least 2 hours before your appointment and avoid drinking liquids for 30 minutes beforehand. If you use a nasal steroid spray or decongestant, take it at least 1 hour before your esketamine treatment.

Driving & Operating Machinery
Tell patient You must not drive, operate heavy machinery, or engage in any activity requiring full alertness until the day after treatment, following a restful sleep. Arrange transportation home from every treatment session.
Call prescriber If you still feel drowsy, confused, or “not yourself” the morning after treatment.
Dissociation & Perceptual Changes
Tell patient You may feel disconnected from your surroundings, experience altered sense of time, or have unusual sensory perceptions (visual changes, tingling, numbness). These effects are temporary and typically pass within 1–2 hours. The clinical team will be present to support you throughout.
Call prescriber If dissociative feelings persist for many hours after leaving the clinic, or if you experience hallucinations or severe paranoia.
Blood Pressure Increases
Tell patient Your blood pressure will be checked before and after each treatment. A temporary rise is expected and usually returns toward normal over approximately 2–4 hours. If you have high blood pressure, make sure it is well controlled with your regular medications.
Call prescriber If you develop sudden severe headache, chest pain, shortness of breath, or visual disturbances after leaving the clinic.
Nausea & Vomiting
Tell patient Nausea is one of the most common side effects. Fasting for 2 hours before treatment significantly reduces the risk. If nausea recurs at multiple sessions, your treatment team may offer an anti-nausea medication beforehand.
Call prescriber If vomiting is severe or if you are unable to keep down your oral medications.
Mood Changes & Suicidal Thoughts
Tell patient While esketamine aims to improve depression, some patients may experience worsening mood, increased anxiety, or new suicidal thoughts, especially early in treatment or when doses change. Inform a trusted person about your treatment so they can watch for changes.
Call prescriber Immediately if you have new or worsening thoughts of self-harm, feel significantly more anxious or agitated, or if family/friends notice concerning behavioural changes.
Substance Use & Abuse Potential
Tell patient Esketamine is a controlled substance related to ketamine. It is administered only at the clinic and cannot be taken home. Avoid alcohol on dosing days and for at least 24 hours afterward. Be open about any history of substance use so the treatment team can provide appropriate support.
Call prescriber If you feel cravings for the medication between sessions or find yourself seeking additional ketamine outside of prescribed treatment.
Pregnancy & Contraception
Tell patient Esketamine may harm a developing fetus based on animal studies. If you are of childbearing potential, discuss effective contraception with your clinician before starting treatment. Breastfeeding is not recommended during treatment.
Call prescriber If you become pregnant or suspect pregnancy during treatment — esketamine should be discontinued.
Ref

Sources

Regulatory (PI / SmPC)
  1. SPRAVATO (esketamine) nasal spray, CIII. Full Prescribing Information. Janssen Pharmaceuticals, Inc. Revised 03/2026. Janssen Labels Primary source for all dosing, contraindications, adverse reaction incidence rates, and pharmacokinetic parameters.
  2. FDA Approval Letter — Supplemental NDA for Spravato Monotherapy (January 21, 2025). FDA Access Data Documents the 2025 approval of esketamine as monotherapy for TRD without mandatory oral antidepressant.
  3. SPRAVATO REMS Program. SPRAVATOrems.com Outlines the Risk Evaluation and Mitigation Strategy requirements for healthcare settings and pharmacies.
Key Clinical Trials
  1. Fedgchin M, Trivedi M, Daly EJ, et al. Efficacy and safety of fixed-dose esketamine nasal spray combined with a new oral antidepressant in treatment-resistant depression: results of a randomized, double-blind, active-controlled study (TRANSFORM-1). Int J Neuropsychopharmacol. 2019;22(10):616–630. DOI Phase 3 fixed-dose TRD trial demonstrating efficacy of 56 mg and 84 mg esketamine.
  2. Popova V, Daly EJ, Trivedi M, et al. Efficacy and safety of flexibly dosed esketamine nasal spray combined with a newly initiated oral antidepressant in treatment-resistant depression: a randomized double-blind active-controlled study (TRANSFORM-2). Int J Neuropsychopharmacol. 2019;22(10):631–640. DOI Pivotal flexible-dose TRD study showing statistically significant improvement versus active comparator.
  3. Daly EJ, Trivedi MH, Janik A, et al. Efficacy of esketamine nasal spray plus oral antidepressant treatment for relapse prevention in patients with treatment-resistant depression: a randomized clinical trial (SUSTAIN-1). JAMA Psychiatry. 2019;76(9):893–903. DOI Withdrawal-design maintenance trial demonstrating relapse prevention with continued esketamine treatment.
  4. Wajs E, Aluisio L, Holder R, et al. Esketamine nasal spray plus oral antidepressant in patients with treatment-resistant depression: assessment of long-term safety in a phase 3, open-label study (SUSTAIN-2). J Clin Psychiatry. 2020;81(3):19m12891. DOI Long-term (up to 1 year) open-label safety study; 9.5% discontinuation due to adverse events.
  5. Fu DJ, Ionescu DF, Li X, et al. Esketamine nasal spray for rapid reduction of major depressive disorder symptoms in patients who have active suicidal ideation with intent: double-blind, randomized study (ASPIRE I). J Clin Psychiatry. 2020;81(3):19m13191. DOI Phase 3 trial in MDD with acute suicidal ideation; primary basis for the MDD-SI indication.
Guidelines
  1. McIntyre RS, Rosenblat JD, Nemeroff CB, et al. Synthesizing the evidence for ketamine and esketamine in treatment-resistant depression: an international expert opinion on the available evidence and implementation. Am J Psychiatry. 2021;178(5):383–399. DOI International expert consensus on clinical positioning, patient selection, and practical implementation of esketamine in TRD.
  2. APA Practice Guidelines. Practice Guideline for the Treatment of Patients with Major Depressive Disorder, Third Edition. Am J Psychiatry. 2010. APA Online Foundational guideline on MDD management; esketamine is addressed in subsequent APA updates and position statements.
Mechanistic / Basic Science
  1. Zanos P, Moaddel R, Morris PJ, et al. Ketamine and ketamine metabolite pharmacology: insights into therapeutic mechanisms. Pharmacol Rev. 2018;70(3):621–660. DOI Comprehensive review of ketamine/esketamine receptor pharmacology and the AMPA-BDNF-mTOR signalling hypothesis.
Pharmacokinetics / Special Populations
  1. Perez-Ruixo C, Rossenu S, Zannikos P, et al. Population pharmacokinetics of esketamine nasal spray and its metabolite noresketamine in healthy subjects and patients with treatment-resistant depression. Clin Pharmacokinet. 2021;60(4):501–516. DOI Population PK model quantifying nasal and oral bioavailability fractions, hepatic flow-limited clearance, and covariate effects.
  2. Ochs-Ross R, Daly EJ, Zhang Y, et al. Efficacy and safety of esketamine nasal spray plus an oral antidepressant in elderly patients with treatment-resistant depression — TRANSFORM-3. Am J Geriatr Psychiatry. 2020;28(2):121–141. DOI Phase 3 trial in patients ≥65 years; informs geriatric dosing recommendations and safety considerations.
  3. Fountoulakis KN, Saitis A, Schatzberg AF. Esketamine treatment for depression in adults: a PRISMA systematic review and meta-analysis. Am J Psychiatry. 2025;182(3):259–275. DOI Most recent comprehensive meta-analysis of esketamine efficacy across TRD and MDD-SI trials with pooled NNT estimates.