Medication approval journey
paroxetine (Paxil)
Approved for Major depressive disorder in adults
Before changing anything
Stopping abruptly causes withdrawal effects that can be severe
Stopping or reducing an SSRI too fast commonly causes withdrawal symptoms — dizziness, electric-shock sensations, insomnia, agitation. These are often more severe and far longer-lasting than the "one to two weeks" many people are told. Any change should be a slow, prescriber-supervised taper.
How long the trials actually ran
The longest trial behind the paroxetine approval ran 52 weeks (about 12 months).
The gap between how long the trials ran and how long people actually take these medications is the single most important thing on this page. It is not evidence that longer use is unsafe or ineffective. It is evidence that longer use was not what got tested.
The boxed warning
The strongest warning the FDA puts on a label, reproduced word for word — not our summary of it.
BOXED WARNING WARNING: SUICIDAL THOUGHTS AND BEHAVIORS Antidepressants increased the risk of suicidal thoughts and behaviors in pediatric and young adult patients in short-term studies. Closely monitor all antidepressant-treated patients for clinical worsening, and for emergence of suicidal thoughts and behaviors [see Warnings and Precautions ( 5.1 )]. Paroxetine is not approved for use in pediatric patients [see Use in Specific Populations ( 8.4 )]. WARNING: SUICIDAL THOUGHTS AND BEHAVIORS See full prescribing information for complete boxed warning. Increased risk of suicidal thoughts and behavior in pediatric and young adult patients taking antidepressants. Closely monitor all antidepressant-treated patients for clinical worsening and emergence of suicidal thoughts and behaviors. Paroxetine is not approved for use in pediatric patients. ( 5.1 , 8.4 )
FDA label effective August 21, 2026 — read the full label on DailyMed
How many Americans take paroxetine
Survey-based federal estimates, published with a lag of about two years. They count prescriptions filled, not outcomes.
- 7,173,801
- prescriptions in the United States (2024)
- 1,681,957
- people filling them (2024)
Prescriptions are down 52% since 2014. Whatever you decide about paroxetine, you are deciding alongside about 1,681,957 other people this year.
Source: ClinCalc DrugStats (Medical Expenditure Panel Survey (MEPS), Agency for Healthcare Research and Quality), CC BY-SA 4.0, release 2026.08.
What people report to the FDA about paroxetine
Read this before the numbers.
Anyone can file an adverse event report — patients, doctors, manufacturers — and nobody verifies that the drug caused what was reported. There is no denominator: tens of millions of prescriptions generate reports at an unknowable rate, and reporting rises with news coverage, not necessarily with harm. Counts below are report volumes, not rates, and cannot be compared between drugs. The FDA itself says not to use this data to make medical decisions — we show it because you deserve to see what is in the public record, with its limits stated plainly.
- 91,207
- reports mentioning paroxetine, all time
- 62,242
- filed as serious (a report-level flag covering every drug and outcome in the report)
Most-reported reactions
- Drug ineffective6,311
- Drug withdrawal syndrome6,210
- Nausea6,139
- Dizziness5,469
- Fatigue5,430
- Anxiety5,396
- Headache4,832
- Depression4,322
- Diarrhoea3,923
- Insomnia3,890
“Drug ineffective” ranking this high is worth noticing: a report of not being helped counts as an adverse event too, and people file them in large numbers.
Source: FDA Adverse Event Reporting System (FAERS), via openFDA, data through 2026-07-30.
Known interactions, from the label
The FDA label’s interactions section, verbatim. A pharmacist checking your actual medication list beats any published list — including this one.
Read the label’s interactions section
7 DRUG INTERACTIONS Table 9 presents clinically significant drug interactions with paroxetine. Table 9 Clinically Significant Drug Interactions with Paroxetine Monoamine Oxidase Inhibitors (MAOIs) Clinical Impact The concomitant use of SSRIs, including paroxetine, and MAOIs increases the risk of serotonin syndrome. Intervention Paroxetine is contraindicated in patients taking MAOIs, including MAOIs such as linezolid or intravenous methylene blue [see Dosage and Administration ( 2.5 ), Contraindications ( 4 ), Warnings and Precautions ( 5.2 )] . Examples selegiline, tranylcypromine, isocarboxazid, phenelzine, linezolid, methylene blue Pimozide and Thioridazine Clinical Impact Increased plasma concentrations of pimozide and thioridazine, drugs with a narrow therapeutic index, may increase the risk of QTc prolongation and ventricular arrhythmias. Intervention Paroxetine is contraindicated in patients taking pimozide or thioridazine [see Contraindications ( 4 )] . Other Serotonergic Drugs Clinical Impact The concomitant use of serotonergic drugs with paroxetine increases the risk of serotonin syndrome. Intervention Monitor patients for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increases. If serotonin syndrome occurs, consider discontinuation of paroxetine and/or concomitant serotonergic drugs [see Warnings and Precautions ( 5.2 )] . Examples other SSRIs, SNRIs, triptans, tricyclic antidepressants, opioids, lithium, tryptophan, buspirone, amphetamines and St. John's Wort. Drugs that Interfere with Hemostasis (antiplatelet agents and anticoagulants) Clinical Impact The concurrent use of an antiplatelet agent or anticoagulant with paroxetine may potentiate the risk of bleeding. Intervention Inform patients of the increased risk of bleeding associated with the concomitant use of paroxetine and antiplatelet agents and anticoagulants. For patients taking warfarin, carefully monitor the international normalized ratio [see Warnings and Precautions ( 5.5 )] . Examples aspirin, clopidogrel, heparin, warfarin Drugs Highly Bound to Plasma Protein Clinical Impact Paroxetine is highly bound to plasma protein. The concomitant use of paroxetine with another drug that is highly bound to plasma protein may increase free concentrations of paroxetine or other tightly-bound drugs in plasma. Intervention Monitor for adverse reactions and reduce dosage of paroxetine or other protein-bound drugs as warranted. Examples warfarin Drugs Metabolized by CYP2D6 Clinical Impact Paroxetine is a CYP2D6 inhibitor [see Clinical Pharmacology ( 12.3 )] . The concomitant use of paroxetine with a CYP2D6 substrate may increase the exposure of the CYP2D6 substrate. Intervention Decrease the dosage of a CYP2D6 substrate if needed with concomitant paroxetine use. Conversely, an increase in dosage of a CYP2D6 substrate may be needed if paroxetine is discontinued. Examples propafenone, flecainide, atomoxetine, desipramine, dextromethorphan, metoprolol, nebivolol, perphenazine, tolterodine, venlafaxine, risperidone. Tamoxifen Clinical Impact Concomitant use of tamoxifen with paroxetine may lead to reduced plasma concentrations of the active metabolite (endoxifen) and reduced efficacy of tamoxifen Intervention Consider use of an alternative antidepressant with little or no CYP2D6 inhibition [see Warnings and Precautions ( 5.11 )] . Fosamprenavir/Ritonavir Clinical Impact Co-administration of fosamprenavir/ritonavir with paroxetine significantly decreased plasma levels of paroxetine. Intervention Any dose adjustment should be guided by clinical effect (tolerability and efficacy). Drugs Highly Bound to Plasma Protein: Monitor for adverse reactions and reduce dosage of paroxetine or other protein-bound drugs (e.g., warfarin) as warranted. ( 7 ) Drugs Metabolized by CYP2D6: Reduce dosage of drugs metabolized by CYP2D6 as warranted. ( 7 ) Concomitant use with tamoxifen: Consider use of an alternative antidepressant with little or no CYP2D6 inhibition. ( 5.11 , 7 )
FDA label for paroxetine, effective August 21, 2026 — DailyMed.
Who pays for paroxetine
Two claims datasets and one survey, covering different populations with different instruments — they cannot be reconciled by arithmetic, and where their sum crowds the all-payer estimate, that is a finding about the estimates rather than a percentage.
- Medicare Part D
- Read the under-65 group correctly before the numbers: Medicare before 65 means the disabled and dual-eligible population — among the sickest, highest-need people in the program — and reading their utilization as typical adult use would be a category error. The beneficiary total sums brand-level rows, so treat it as an upper bound on distinct people. 721,377 beneficiaries filled 3,478,176 claims in 2024 — 594,298 aged 65 and over, and 127,079 under 65.
- Medicaid
- At least 1,219,170 prescriptions in 2024 — a floor, because 184 of 940 national data rows are suppressed for privacy and contribute zero. Medicaid covers more children than any insurer in the country and publishes no age split — how much of this number is pediatric use is not knowable from public data.
- All payers (survey estimate)
- The MEPS-based estimate above puts the whole country at 7,173,801 prescriptions and 1,681,957 people in 2024. Subtracting the public programs from it would produce a number for everyone else — and we do not print that number, because subtracting a survey from claims counts manufactures precision that does not exist.
- The population nobody counts
- The commercially insured working-age adult — statistically, the likeliest person to be reading this page — is the one population with no public per-drug count anywhere. Private claims data exists and is sold, but nothing a patient can check is published. For children the record is thinner still: no public source counts pediatric use of paroxetine specifically; the closest the public record comes is condition-level treatment rates for children, which we have traced for one condition in how childhood ADHD got counted.
Sources: Medicare Part D Prescribers — by Geography and Drug, data.cms.gov, National rows, data year 2024 (published with ~17-month lag). Medicaid State Drug Utilization Data 2024, data.medicaid.gov, national aggregate rows. Retrieved 2026-09-01.
The approval, step by step
Step 1
What the approval was actually based on
Which studies did the FDA rely on, how long did they run, and who was in them?
The efficacy of PAXIL as a treatment for major depressive disorder (MDD) has been established in 6 placebo-controlled studies of patients with MDD (aged 18 to 73)... Patients who responded to PAXIL (HDRS total score <8) during an initial 8-week open-label treatment phase were then randomized to continue PAXIL or placebo, for up to 1 year. Patients treated with PAXIL demonstrated a statistically significant lower relapse rate during the withdrawal phase (15%) compared to those on placebo (39%).
FDA-approved labelling, 14 CLINICAL STUDIES 14.1 Major Depressive Disorder — read the label on DailyMed
Our reading
Six short trials plus a full year of randomised withdrawal is one of the better duration records here, and the relapse split — 15% against 39% — is a large effect. Read the design before you read the number. Randomised withdrawal takes people already doing well on the drug and switches some to placebo, so it cannot separate relapse of the illness from withdrawal from the medication. Paroxetine has the shortest half-life of the common SSRIs and the most severe documented discontinuation syndrome, which makes that ambiguity larger for this drug than for any other on this list.
Step 2
The approval
When was it approved, under what application, and by whose review?
- Approved
- December 29, 1992
- Application
- NDA020031
- Review
- STANDARD
- Original sponsor
- SmithKline Beecham (now GlaxoSmithKline)
- Holds it now
- Apotex
- Label submissions since
- 64
Source: openFDA Drugs@FDA, original application ORIG-1
Step 3
What was added after it was on the market
Which warnings arrived only after millions of people were already taking it?
PRAC recommendations on signals adopted at the 13-16 May 2019 PRAC meeting, section 1.3: SNRIs and SSRIs - persistent…
27 years after approval
On 16 May 2019 the EU drug regulator's safety committee ordered every manufacturer of citalopram, escitalopram, fluvoxamine, fluoxetine, paroxetine, sertraline, duloxetine, venlafaxine, desvenlafaxine, and milnacipran to add this warning within two months: "There have been reports of long-lasting sexual dysfunction where the symptoms have continued despite discontinuation of SSRIs/SNRI." The patient leaflet wording is "In some cases, these symptoms have continued after stopping treatment." This is a regulator acting on case reports and pharmacovigilance data, not a prevalence study — how often it happens is still unknown, and that uncertainty cuts both ways.
Worth asking
European regulators require a label warning that sexual side effects can persist after stopping an SSRI or SNRI — how would you and I tell that apart from the depression itself if it happened to me?
The antidepressant suicidality warning has an age ceiling most people never hear about
Antidepressants carry a boxed warning about suicidal thoughts and behaviour in children, adolescents and young adults. It came from pooling 24 short-term placebo-controlled trials of nine antidepressants in more than 4,400 young patients: suicidality was reported in about 4% on drug against 2% on placebo. There were no completed suicides in those trials.
The part that usually gets lost is the age boundary, which is in the label itself. The studies did not show an increased risk above age 24, and in patients 65 and older the risk went in the other direction — it was reduced. The warning is real and it is specific, not a blanket statement about everyone who takes one.
Worth asking
Given my age, which side of that line am I on, what specifically should I or the people around me watch for in the first two months, and who do I call if it happens.
Step 4
What independent research has found since
What has been learned by people who were not selling it?
Comparative efficacy and acceptability of 21 antidepressant drugs for the acute treatment of adults with major…
26 years after approval
Across 522 randomised trials with 116,477 adults, paroxetine beat placebo and was among the more effective antidepressants in head-to-head comparisons, but it was not among the best tolerated.
Worth asking
Paroxetine scored well on effect but not on tolerability in this comparison - which of its side effects should I watch for most in the first month?
Paroxetine versus other anti-depressive agents for depression
22 years after approval
Pooling 115 randomised trials with 26,134 people, paroxetine was neither clearly better nor clearly worse than other antidepressants overall, with some evidence it was less effective than citalopram on early response.
Worth asking
The evidence says paroxetine is roughly interchangeable with other SSRIs on effect - did a specific symptom or history point you to it for me?
Paroxetine versus other anti-depressive agents for depression — Purgato M, et al. (2014)
Restoring Study 329: efficacy and harms of paroxetine and imipramine in treatment of major depression in adolescence
23 years after approval
An independent reanalysis of GlaxoSmithKline's Study 329 (275 adolescents) found paroxetine was no more effective than placebo for adolescent depression and was associated with clinically significant increases in suicidal ideation and behaviour - reversing the original 2001 publication's conclusions.
Worth asking
Paroxetine is not recommended for people under 18 - given my age and history, what makes it the right SSRI for me rather than one with a cleaner record?
Effectiveness of paroxetine in the treatment of acute major depression in adults: a systematic re-examination of…
16 years after approval
Re-examining 40 published and unpublished placebo-controlled trials (6,391 adults), paroxetine was not superior to placebo on a combined measure of effectiveness and acceptability, and paroxetine patients more often stopped for side effects (77% higher risk) or experienced suicidal tendencies (odds 2.55 times higher).
Worth asking
Unpublished trial data made paroxetine look weaker and riskier than the published record - how do you weigh that when prescribing it today?
Withdrawal from these medications can take months, and NICE says so
30 years after approval
NICE guideline NG215 covers safe prescribing and managed withdrawal for five groups of medication: opioids, benzodiazepines, gabapentinoids, Z-drugs and antidepressants. It is the closest thing there is to an official answer on how coming off actually goes.
It states that withdrawal can be difficult and may take several months or more, that symptoms vary widely in type and severity, that they affect both physical and mental health, and that they can be delayed in onset and can persist. Two recommendations are worth quoting to a prescriber. Do not stop a medicine abruptly except in exceptional medical circumstances. And taper using a slow, stepwise reduction proportionate to the current dose, so the decrements get smaller as the dose gets lower — not a fixed cut each time.
That last detail is the one most commonly missed. Gabapentinoids are the exception in the guideline and are reduced by a fixed amount at each step.
Worth asking
Can we write the taper down, what size are the steps near the end, and how long do I hold at each step before the next reduction.
In 2019 the Royal College of Psychiatrists changed its position on withdrawal
27 years after approval
For years people reporting long, severe antidepressant withdrawal were told it lasted a week or two. In May 2019 the Royal College of Psychiatrists published a position statement conceding the point: while withdrawal symptoms are often mild and self-limiting, there is substantial variation, and for some patients symptoms last much longer and are more severe.
It went further and asked for changes — that guidelines and patient information recognise the potential for severe and long-lasting withdrawal, that pharmacologically-informed tapering guidance be developed, that discontinuation be tapered at a rate the patient can tolerate over potentially several months, and that clinicians actively work to tell withdrawal apart from relapse.
One thing it explicitly does not say, and it is worth being accurate about: the College states that from a clinical perspective antidepressant use is not associated with dependence in the addiction sense. Withdrawal and dependence are not the same claim.
Worth asking
If I feel bad three weeks after a dose reduction, how will we decide whether that is withdrawal or my depression returning, and what do we do differently in each case.
Treatment-emergent sexual dysfunction related to antidepressants: a meta-analysis.
17 years after approval
When sexual function is actually asked about with a questionnaire rather than waited for as a spontaneous complaint, treatment-emergent sexual dysfunction ranged from 25.8% to 80.3% of patients across antidepressants, all significantly above placebo. In descending order of impact the drugs were sertraline, venlafaxine, citalopram, paroxetine, fluoxetine, imipramine, phenelzine, duloxetine, escitalopram, and fluvoxamine. Agomelatine, amineptine, bupropion, moclobemide, mirtazapine, and nefazodone showed no significant difference from placebo.
Worth asking
Where does the antidepressant I'm on sit on the sexual side-effect ranking, and is there a drug with a lower rate that would still treat my condition?
Step 5
What still is not known
Which questions you might reasonably have has nobody answered yet?
- In a randomised-withdrawal trial the placebo group is being withdrawn from a drug, not left untreated. How much of that 39% is relapse and how much is discontinuation?
- Paroxetine has the most difficult discontinuation profile of the SSRIs. Was that discussed when it was started?
- The 2004 boxed warning on suicidality in under-25s came from a pooled re-analysis twelve years after approval, not from these trials.
The legal and safety record
Settled and adjudicated matters only, from primary sources — including the litigation that was decided for the manufacturer, and the cases this drug is verifiably not part of.
Deciding about paroxetine?
- 12 questions to ask before starting a psychiatric medication — each with the study behind it
- Already on it? The 10-question annual review — including the honest case for staying
- How long every drug here was tested before approval — one chart, all medications
Open paroxetine (Paxil) in Resolv
The app has the full approval journey, the resources behind it, and people working through the same questions.
