ziprasidone (Geodon)

How long the ziprasidone trials actually ran

What ziprasidone is FDA approved for, and the trials behind it

Trials

5 placebo-controlled trials

Duration

4 and 6 weeks (short-term trials)

Participants

139 to 419 patients per short-term trial

Compared against

Placebo; haloperidol arm in one trial

The efficacy of oral ziprasidone in the treatment of schizophrenia was evaluated in 5 placebo-controlled studies, 4 short-term (4- and 6-week) trials and one maintenance trial. All trials were in adult inpatients, most of whom met DSM III-R criteria for schizophrenia. Each study included 2 to 3 fixed doses of ziprasidone as well as placebo.

Verbatim from the ziprasidone FDA label, Clinical Studies section, effective August 11, 2026 — read the full label on DailyMed.

Side effects of ziprasidone in the approval trials

• Extrapyramidal symptoms (14% vs 8% on placebo)
• Somnolence (14% vs 7%)
• Nausea (10% vs 7%)
• Constipation (9% vs 8%)
• Akathisia (8% vs 7%)
• Dizziness (8% vs 6%)
• Dyspepsia (8% vs 7%)
• Respiratory tract infection (8% vs 3%)
• Asthenia (5% vs 3%)
• Diarrhea (5% vs 4%)

The following adverse reactions were the most commonly observed adverse reactions associated with the use of ziprasidone (incidence of 5% or greater) and not observed at an equivalent incidence among placebo-treated patients (ziprasidone incidence at least twice that for placebo): Schizophrenia trials ( see Table 11 ) Somnolence Respiratory Tract Infection

From the ziprasidone FDA label, Adverse Reactions section, effective August 11, 2026 — DailyMed.

More from the ziprasidone label: drug abuse and dependence

• Dependence not systematically studied

  Ziprasidone has not been systematically studied, in animals or humans, for its potential for abuse, tolerance or physical dependence. Clinical trials revealed no tendency toward drug-seeking behavior, though the label notes those observations were not systematic, and it advises evaluating patients for a history of drug abuse and observing them closely for signs of misuse.

  FDA label, Drug Abuse and Dependence section.

How many Americans take ziprasidone

No year from 2014 to 2024 meets AHRQ’s reliability rule for this drug, so we print no count. Years not shown, under AHRQ’s reliability rule: 2014, 2015, 2016, 2017, 2018, 2020 (fewer than 60 survey respondents); 2019, 2021, 2022, 2023, 2024 (AHRQ masks the name in the public file).

Correction (29 September 2026). An earlier version of this section took its numbers from ClinCalc DrugStats, a third-party site that republishes this survey; we now compute them from AHRQ’s public-use files ourselves. It showed 189,620 people and 1,262,673 prescriptions for 2020. No year meets AHRQ’s reliability rule for this drug, so that count is removed. It said prescriptions were down 20% since 2014; too few years meet the rule to show a trend, so that line is removed.

Source: AHRQ Medical Expenditure Panel Survey (MEPS), Prescribed Medicines public-use files, 2014 (HC-168A) through 2024 (HC-254A), computed by veisund. People with at least one purchase where the Multum generic name (RXDRGNAM) equals the drug, weighted by the year’s person weight; purchases include refills. Standard errors by Taylor linearization on VARSTR/VARPSU. AHRQ’s reliability rule: a year is not shown when fewer than 60 survey respondents reported the drug or the relative standard error is over 50%. AHRQ cautions that its 2018 questionnaire redesign and the 2020–2022 pandemic years make year-to-year comparisons less certain.

What people report to the FDA about ziprasidone

20,025

reports mentioning ziprasidone, all time

14,098

filed as serious (a report-level flag covering every drug and outcome in the report)

filed as serious. That flag covers the whole report, and one report can name more than one drug and more than one outcome.

Source: FDA Adverse Event Reporting System (FAERS), via openFDA, openFDA dataset refreshed 2026-07-30 (the refresh date of the query endpoint, not the date reports run through).

Drug interactions listed on the ziprasidone label

FDA label for ziprasidone, effective August 11, 2026 — DailyMed.

Who pays for ziprasidone

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. 78,385 beneficiaries filled 636,774 claims in 2024 — 28,704 aged 65 and over, and 49,681 under 65.

Medicaid

At least 512,420 prescriptions in 2024 — a floor, because 176 of 583 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)

No figure. In AHRQ’s MEPS 2024 Prescribed Medicines file, AHRQ masks this drug in the 2024 public-use file (it withholds drug names it estimates fewer than about 400,000 people use), so no public all-payer count exists.

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 ziprasidone 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.

Who has been paying for ziprasidone, 2019–2024

Sources: Medicare Part D Prescribers by Geography and Drug (data.cms.gov, national rows, per data year); Medicaid State Drug Utilization Data (data.medicaid.gov, national rows). Claims, fills and beneficiaries are different units — compare each series only with itself.

The ziprasidone approval, step by step

1. 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 oral ziprasidone in the treatment of schizophrenia was evaluated in 5 placebo-controlled studies, 4 short-term (4- and 6-week) trials and one maintenance trial... Four of the 5 trials were able to distinguish ziprasidone from placebo; one short-term study did not.

   FDA-approved labelling, 14 CLINICAL STUDIES — read the label on DailyMed

   Our reading

   Read the last sentence of that quote again, because labels rarely say it so plainly: one of the five pivotal trials could not tell ziprasidone from placebo, and the FDA printed that and approved the drug anyway — four out of five is how the standard actually works. The QT-prolongation question dominated this drug's review and its early marketing restrictions; the label's cardiac sections are the ones a prescriber will care about most, and they are the reason this drug is taken with food and not combined casually.

2. Step 2

   The approval

   When was it approved, under what application, and by whose review?

   Approved

   February 5, 2001

   Application

   NDA020825

   Review

   STANDARD

   Original sponsor

   Pfizer

   Holds it now

   Viatris

   Label submissions since

   35

   Source: openFDA Drugs@FDA, original application ORIG-1

3. Step 3

   What was added after it was on the market

   Which warnings arrived only after millions of people were already taking it?

   • Antipsychotics raise the risk of death in older people with dementia

     This is one of the clearest harm signals in psychiatric medicine, and it applies to a specific group: older adults with dementia-related psychosis. Pooling 17 placebo-controlled trials covering 5,106 patients over roughly 10 weeks, the risk of death was 1.6 to 1.7 times higher on an antipsychotic than on placebo — about 4.5% against 2.6%. Most deaths were cardiovascular or infectious, chiefly heart failure, sudden death and pneumonia.

     The FDA first applied this warning to the newer antipsychotics in 2005 and extended it to the older ones in 2008. No antipsychotic is approved for dementia-related psychosis.

     If this is being prescribed for an older relative with dementia, worth asking: what specific behaviour are we treating, what have we tried that is not a drug, what is the shortest time we can plan for, and when will we review stopping.

     RISPERDAL (risperidone) prescribing information — Boxed Warning: Increased Mortality in Elderly Patients with Dementia-Related Psychosis — U.S. Food and Drug Administration (approved labelling)

4. Step 4

   What independent research has found since

   What has been learned by people who were not selling it?

   • QT prolongation from psychiatric drugs is a real but imperfect risk marker; the arrhythmia itself is unmeasured

     12 years after approval

     The interaction warnings about QT prolongation, which run through the citalopram, pimozide and paroxetine rows of this wave, rest on a marker, not on counted heart rhythm deaths. This review says so.

     Significant findings

     Beach and colleagues (Psychosomatics, 2013) reviewed the literature on the corrected QT interval and psychiatric medication. "QTc interval prolongation is an established, though imperfect, risk marker for TdP" (torsades de pointes, the dangerous rhythm). "There are no well-controlled studies that assess the risk of TdP associated with psychotropic agents."

     What the evidence supports: "There are limited data that selective serotonin reuptake inhibitors (SSRIs) as a class are linked to QTc prolongation; citalopram appears more likely than others to induce this phenomenon. Among antipsychotics, thioridazine remains the agent most associated with QTc prolongation; intravenous haloperidol also appears to carry an increased risk. Of the atypical antipsychotics, ziprasidone appears most likely to prolong the QTc interval."

     And the proportion: "The majority of patients in need of psychotropic medications display few risk factors for QTc prolongation and should be considered to be at low risk for TdP. The frequency of cardiac monitoring for patients receiving psychiatric medications should be individually determined, based on the prescribed agent(s) and additional risk factors for TdP."

     Worth asking

     This is the review to hold beside the labels. The labels say avoid stacking QT drugs; the review says the stacking matters most for people who already have risk factors, such as heart disease, low potassium or magnesium, or a congenital long QT, and that the harm at the end of the chain has never been measured in a controlled study. If you take two drugs from the QT lists, the question is whether you have any of those risk factors and whether anyone has looked at an ECG.

     QTc prolongation, torsades de pointes, and psychotropic medications — Beach SR, Celano CM, Noseworthy PA, Januzzi JL, Huffman JC (2013)

   • Grapefruit interacts with more than 85 drugs, including buspirone, quetiapine, lurasidone, ziprasidone and pimozide

     12 years after approval

     The one interaction in this wave that comes from the breakfast table.

     Significant findings

     Bailey, Dresser and Arnold (CMAJ, 2013) reviewed the grapefruit literature. "Currently, more than 85 drugs ... are known or predicted to interact with grapefruit," and between 2008 and 2012 the number with the potential for serious adverse effects rose "from 17 to 43."

     The mechanism is furanocoumarins in the fruit causing "irreversible inactivation" of the enzyme CYP3A4 in the small intestine, so that drugs normally broken down there reach the blood in larger amounts. Because the enzyme is destroyed rather than blocked, the effect outlasts the fruit: a dose taken within 4 hours of grapefruit shows the maximal interaction, at 10 hours the effect is "50% of the maximum," at 24 hours "25% of the maximum." "One whole grapefruit or 200 mL of grapefruit juice is sufficient" to produce a clinically relevant effect.

     On who is affected: "Older people appear to be an especially vulnerable population for grapefruit-drug interactions," with pronounced effects in patients over 70.

     The psychiatric and neurological drugs in the review's tables include buspirone, quetiapine, lurasidone, ziprasidone, pimozide, dextromethorphan, oral ketamine, oxycodone, oral fentanyl and triazolam.

     Worth asking

     Most of the drugs on the list are raised, not lowered, which for an antipsychotic means more sedation and, for pimozide and ziprasidone, more QT prolongation. The pharmacist's answer to "can I drink grapefruit juice" depends entirely on which drugs you take, and the review's 24-hour figure means "not at the same time as the pill" is not the same as "not at all." Seville oranges, used in marmalade, contain the same compounds.

     Grapefruit-medication interactions: forbidden fruit or avoidable consequences? — Bailey DG, Dresser G, Arnold JM (2013)

5. Step 5

   What still is not known

   Which questions you might reasonably have has nobody answered yet?

   • One pivotal trial failed to beat placebo and the label says so. How many prescribers quoting "proven efficacy" have read that sentence?
   • The QT concern shaped the approval. What monitoring, if any, is happening now?
   • Must be taken with food to absorb properly — a practical fact that quietly determines whether the prescribed dose is the received dose.