Ziprasidone and Amitriptyline: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Amitriptyline
Ziprasidone
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
Both of these medicines can affect your heart's rhythm. Amitriptyline (Elavil) and ziprasidone (Geodon) can each stretch out a part of your heartbeat called the QT interval. Taken together, that effect can add up and, in rare cases, lead to a dangerous heart rhythm.
They can also both raise serotonin, a brain chemical. Too much can cause serotonin syndrome, with symptoms like agitation, a racing heart, sweating, shaking, or a high fever. This is why the combination is generally avoided. The good news: your doctor and pharmacist can manage this safely, so please talk with them before making any changes on your own.
Contraindicated combination. Both agents independently prolong the QT interval, and coadministration produces additive QT prolongation, raising torsades de pointes risk. Both are also serotonergic (amitriptyline via serotonin reuptake inhibition; ziprasidone has reported serotonergic activity), giving additive serotonin syndrome risk.
- Evidence: theoretical/additive; onset unspecified.
- Monitoring: baseline and follow-up ECG/QTc, electrolytes (K+, Mg2+), and clinical signs of serotonin syndrome (autonomic instability, neuromuscular hyperexcitability, mental status changes).
- Management: avoid the combination per labeling; if used, individualize dosing, monitor closely, and discontinue both agents with supportive care if serotonin syndrome emerges.
Neither is a prodrug relevant to this interaction; effects are pharmacodynamic and additive.
What happens
Increased risk of QT interval prolongation and an increased risk of serotonin syndrome (hypertension, hyperthermia, myoclonus, mental status changes)
Interaction Deep Dive
Because of the additive potential for QT interval prolongation, giving ziprasidone alongside other agents that lengthen the QT interval is contraindicated. Serotonin syndrome has additionally been described both with ziprasidone used alone and when it is combined with other serotonergic medications. Manifestations can involve altered mental status (for example, agitation, hallucinations, delirium, and coma), autonomic instability (for example, tachycardia, labile blood pressure, dizziness, diaphoresis, flushing, hyperthermia), neuromuscular findings (for example, tremor, rigidity, myoclonus, hyperreflexia, incoordination), seizures, and gastrointestinal complaints (for example, nausea, vomiting, diarrhea). Every patient receiving ziprasidone should be watched for the development of serotonin syndrome. Should these symptoms arise, stop ziprasidone and any accompanying serotonergic agents right away and begin supportive symptomatic care. When there is a clinical justification for using ziprasidone together with other serotonergic drugs, advise patients about the heightened risk of serotonin syndrome and monitor them for symptoms12.
Why it happens (mechanism)
Additive QT interval prolongation; additive serotonergic effects
How to manage this interaction
This pairing is generally avoided, but do not stop or change either medicine on your own. Keep taking both exactly as prescribed until you speak with your care team.
- Your team may run an ECG (heart tracing) and check electrolytes like potassium and magnesium.
- They may choose an alternative medicine, or if both are truly needed, watch you more closely and individualize your doses.
- Get urgent help for a racing or irregular heartbeat, fainting, high fever, severe sweating, shaking, muscle stiffness, agitation, or confusion.
Ask your pharmacist or prescriber whether this combination is right for you and what warning signs to watch for.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) A 30-year-old woman experienced serotonin syndrome after sertraline was started for ongoing depressive symptoms while she was concurrently receiving ziprasidone 40 mg/day. Following the discontinuation of paroxetine due to inadequate response, sertraline was begun at 50 mg/day and increased to 125 mg/day over the course of 4 weeks. Two days afterward, the patient presented with severe anxiety, jerking movements of the upper extremities, transient headaches, confusion, diaphoresis, hyperreflexia, and frequent myoclonus. Sertraline was stopped, ziprasidone was reduced to 20 mg/day, and the patient received IV fluids along with clonazepam 0.5 mg twice daily; her symptoms cleared within 48 hours. The combination of ziprasidone, a potent serotonin 5-hydroxytryptamine-1A receptor agonist, with the greater inhibition of serotonin reuptake resulting from the sertraline dose increase probably contributed to the emergence of serotonin syndrome in this instance 3.
Common questions
Can I take Ziprasidone and Amitriptyline together?
Amitriptyline and ziprasidone together can add up to prolong the QT interval and raise serotonin syndrome risk, so this combination is generally avoided. Do not change anything yourself; talk with your doctor or pharmacist promptly. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ziprasidone and Amitriptyline interaction?
It is rated contraindicated. These should generally not be used together.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Ziprasidone and Amitriptyline interaction managed?
This pairing is generally avoided, but do not stop or change either medicine on your own. Keep taking both exactly as prescribed until you speak with your care team. Your team may run an ECG (heart tracing) and check electrolytes like potassium and magnesium. They may choose an alternative medicine, or if both are truly needed, watch you more closely and individualize your doses. Get urgent help f… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Ziprasidone or Amitriptyline need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (3)
- Product Information: GEODON(R) intramuscular injection, ziprasidone mesylate intramuscular injection. Viatris Specialty LLC(per FDA), Morgantown, WV, 2025.
- Product Information: GEODON(R) oral capsules, ziprasidone oral capsules. Viatris Specialty LLC(per FDA), Morgantown, WV, 2025. DailyMed
- Palekar N & Eisman J: Serotonin syndrome with ziprasidone and sertraline. J Neuropsychiatry Clin Neurosci 2013; 25(2):E1. PubMed
Keep reading about Amitriptyline
Keep reading about Ziprasidone
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