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Paroxetine IR
Paroxetine IR is a Selective serotonin reuptake inhibitor (SSRI) Small molecule drug developed by GlaxoSmithKline. It is currently in Phase 3 development for Major depressive disorder, Generalized anxiety disorder, Panic disorder. Also known as: Paroxetine CR.
Paroxetine selectively inhibits the reuptake of serotonin at the neuronal synapse, increasing serotonin availability in the brain.
Paroxetine selectively inhibits the reuptake of serotonin at the neuronal synapse, increasing serotonin availability in the brain. Used for Major depressive disorder, Generalized anxiety disorder, Panic disorder.
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Baseline phase 3 → approval rate
+58.3pp
Industry-wide phase 3 drugs reach approval ~58.3% of the time (BIO/Informa 2023 industry benchmark across all therapeutic areas). -
CNS / neurology attrition
-3.0pp
CNS drugs have historically high Phase 3 failure rates (notably in Alzheimer disease + major depression). -
Big-pharma sponsor
+3.0pp
GlaxoSmithKline is a top-20 pharma sponsor — historical approval rates run ~3pp above average due to scale, regulatory experience, and trial-design quality.
| Regulator | Country | Likely year | Lag vs FDA |
|---|---|---|---|
| FDA | US | 2028–2030 | — |
| EMA | EU | 2029–2031 | +0.7 yr |
| MHRA | GB | 2029–2031 | +0.7 yr |
| Health Canada | CA | 2029–2032 | +0.9 yr |
| TGA | AU | 2029–2032 | +1.2 yr |
| PMDA | JP | 2029–2032 | +1.5 yr |
| NMPA | CN | 2030–2033 | +2.3 yr |
| MFDS | KR | 2029–2032 | +1.4 yr |
| CDSCO | IN | 2029–2033 | +1.8 yr |
| ANVISA | BR | 2030–2033 | +2.3 yr |
Hover any row for the lag rationale. Lag estimates are reduced when the drug has FDA Breakthrough or EMA PRIME designation (sponsors file globally in parallel).
Estimate based on the BIO/Informa industry phase transition rates plus per-drug modifiers for therapeutic area, sponsor type, FDA designations, mechanism, and trial design. Per-jurisdiction lags from Tufts CSDD international approval studies. Not investment, clinical or regulatory advice. Methodology: /methodology#likelihood.
At a glance
| Generic name | Paroxetine IR |
|---|---|
| Also known as | Paroxetine CR |
| Sponsor | GlaxoSmithKline |
| Drug class | Selective serotonin reuptake inhibitor (SSRI) |
| Target | Serotonin transporter (SERT) |
| Modality | Small molecule |
| Therapeutic area | Psychiatry/Neurology |
| Phase | Phase 3 |
Mechanism of action
Paroxetine is a selective serotonin reuptake inhibitor (SSRI) that blocks the serotonin transporter protein, preventing the reabsorption of serotonin from the synaptic cleft back into presynaptic neurons. This increases serotonin concentration in the synapse, enhancing neurotransmission and improving mood regulation. The IR (immediate-release) formulation allows rapid absorption and onset of action compared to extended-release formulations.
Approved indications
- Major depressive disorder
- Generalized anxiety disorder
- Panic disorder
- Obsessive-compulsive disorder
- Post-traumatic stress disorder
- Social anxiety disorder
Common side effects
- Nausea
- Headache
- Sexual dysfunction
- Insomnia
- Somnolence
- Diarrhea
- Tremor
- Sweating
Key clinical trials
- Clinical Study to Investigate the Effect of the Combination of Psychotropic Drugs and an Opioid on Ventilation (PHASE1)
- Influence of Oxycodone on Individuals Taking an SSRI (PHASE1)
- Bioequivalence Study of Paroxetine Immediate Release (IR) Tablets Manufactured in GlaxoSmithKline Tianjin (GSKT) and Mississauga Sites in Healthy Chinese Subjects (PHASE1)
- Repeat Dose Study of Controlled-Release Paroxetine Tablets and Immediate-Release Paroxetine Tablets in Healthy Japanese Male Subjects (PHASE1)
- Evaluation of the Safety of Adjunct Brexpiprazole in Elderly Patients With Major Depressive Disorder and an Inadequate Response to Antidepressant Treatment (PHASE3)
- Brexpiprazole as Adjunctive Treatment in Patients With Major Depressive Disorder With an Inadequate Response to Antidepressant Treatment (PHASE3)
- Controlled-release Paroxetine in Major Depressive Disorder (Double-blind, Placebo-controlled Study) (PHASE3)
- A Local Register Study For Major Depression Of Paroxetine Controlled Release (PHASE3)
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |
Competitive intelligence
For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:
- Paroxetine IR CI brief — competitive landscape report
- Paroxetine IR updates RSS · CI watch RSS
- GlaxoSmithKline portfolio CI
Frequently asked questions about Paroxetine IR
What is Paroxetine IR?
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What is Paroxetine IR used for?
Who makes Paroxetine IR?
Is Paroxetine IR also known as anything else?
What drug class is Paroxetine IR in?
What development phase is Paroxetine IR in?
What are the side effects of Paroxetine IR?
What does Paroxetine IR target?
Related
- Drug class: All Selective serotonin reuptake inhibitor (SSRI) drugs
- Target: All drugs targeting Serotonin transporter (SERT)
- Manufacturer: GlaxoSmithKline — full pipeline
- Therapeutic area: All drugs in Psychiatry/Neurology
- Indication: Drugs for Major depressive disorder
- Indication: Drugs for Generalized anxiety disorder
- Indication: Drugs for Panic disorder
- Also known as: Paroxetine CR
Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing