Sertraline and Iobenguane I 131: 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
Sertraline
No brand names on recordIobenguane I 131
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.
Here's what's going on. Azedra (iobenguane I-131) is a radioactive medicine that works by getting taken up into certain cells so it can find and treat them. Sertraline, an antidepressant, can block that uptake. If the Azedra can't get into the cells the way it should, the imaging and dose calculations may be off, and the treatment may not work as well.
The good news: this is very manageable. Your care team plans the timing carefully. They typically have you pause the interfering medicine for a stretch before your Azedra and wait about a week after each dose before restarting. Please don't stop sertraline on your own, let your doctor or pharmacist guide the timing.
Mechanism: Iobenguane I-131 relies on catecholamine (norepinephrine) transporter uptake to concentrate in target cells. Sertraline, an SSRI, can interfere with catecholamine uptake, reducing intracellular iobenguane accumulation.
Direction/effect: Reduced tumor uptake, leading to inaccurate dosimetry and diminished therapeutic efficacy. Neither drug is a prodrug here; this is a pharmacodynamic/uptake interference, not a CYP effect.
- Onset: rapid
- Evidence: theoretical, but severity rated major given the consequences
- Management: Discontinue sertraline at least 5 half-lives before dosimetry and each therapeutic dose; resume no sooner than 7 days after each iobenguane dose.
What happens
Inaccurate dosimetry calculations or reduced efficacy
Interaction Deep Dive
Agents that lower catecholamine uptake or deplete catecholamine reserves, such as SSRIs and serotonin norepinephrine reuptake inhibitors (SNRIs), can impair the cellular uptake of iobenguane, which may compromise dosimetry calculations or diminish the effectiveness of iobenguane I-131. These medications should be stopped for a minimum of 5 half-lives prior to giving either a dosimetry or therapeutic dose of iobenguane I-131, and reintroduction of the interfering agent(s) should not occur until at least 7 days have elapsed following each iobenguane I-131 dose1.
Why it happens (mechanism)
Interference with iobenguane uptake into cells
How to manage this interaction
What the care team usually does:
- Reviews all your medicines before Azedra and identifies ones that can block uptake, like sertraline.
- Has you stop the interfering medicine far enough ahead (at least 5 half-lives) so it clears before the dosimetry scan and each treatment dose.
- Waits at least 7 days after each iobenguane dose before restarting it.
What you should do: Keep taking sertraline as prescribed until your team tells you otherwise, and let them handle the timing. Tell your oncology and nuclear medicine teams that you take sertraline, and ask your pharmacist or prescriber how and when to pause and restart it safely.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Sertraline and Iobenguane I 131 together?
Sertraline can block iobenguane I-131 from entering target cells, throwing off dosing calculations and treatment effect. Your team will time stopping and restarting it around your Azedra doses, so coordinate the schedule with them rather than changing anything yourself. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Sertraline and Iobenguane I 131 interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
How is the Sertraline and Iobenguane I 131 interaction managed?
What the care team usually does: Reviews all your medicines before Azedra and identifies ones that can block uptake, like sertraline. Has you stop the interfering medicine far enough ahead (at least 5 half-lives) so it clears before the dosimetry scan and each treatment dose. Waits at least 7 days after each iobenguane dose before restarting it. What you should do: Keep taking sertraline as prescr… 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 Sertraline or Iobenguane I 131 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 (1)
- Product Information: AZEDRA(R) intravenous injection, iobenguane I 131 intravenous injection. Progenics Pharmaceuticals Inc (per FDA), New York, NY, 2018.
Keep reading about Sertraline
Keep reading about Iobenguane I 131
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