Monitoring and safety
Lecanemab: use the current route-specific MRI schedule
An old infusion checklist can miss an early MRI, and an infusion number can mislead when the route changes. FDA called for earlier lecanemab monitoring in 2025. The current label checked for this lesson expresses routine monitoring by treatment months and distinguishes intravenous from subcutaneous dosing.
Sources checked October 8, 2026. Independent educational content, not NABP exam questions or individual treatment advice.
Read the current label rather than an old checklist
The August 2025 FDA communication added an MRI before the third infusion to the previously described fifth, seventh and fourteenth infusion checks. That announcement explains why an older checklist can be incomplete; it is not a substitute for the full current prescribing information.
The DailyMed label checked on October 8 calls for a recent baseline MRI and MRIs after one, two, three and six months of treatment. It gives one-month examples of before the third IV dose or fifth subcutaneous dose. Record the route and actual treatment timeline instead of applying an infusion number to every formulation.
Review the scan before proceeding
The current label says the MRI should generally be performed within approximately one week before the next scheduled infusion or injection and reviewed before proceeding. A scan booked after the dose does not satisfy a before-dose review merely because it is in the same calendar month.
Scheduling and clinical clearance are separate. Recover the report and the treating team's decision, not simply a booking confirmation. This page is a monitoring exercise, not permission to administer, suspend or restart a medicine from a reminder list.
Recognize symptoms between routine scans
Amyloid-related imaging abnormalities can include edema or effusions (ARIA-E) and hemosiderin deposition such as microhemorrhage or superficial siderosis (ARIA-H). They are often asymptomatic, but serious or fatal events can occur. Absence of symptoms is not a reason to delete scheduled imaging.
The label lists headache, confusion, visual changes, dizziness, nausea and gait difficulty among possible symptoms, with focal neurologic deficits also possible. Suspected ARIA needs clinical evaluation and MRI if indicated. New neurological symptoms should not be deferred to the next routine monitoring date.
Keep interruption decisions clinical
Dosing decisions depend on both MRI findings and symptom severity. The label contains interruption tables and additional risk information, including genotype and intracerebral hemorrhage considerations. A single statement that ARIA is asymptomatic cannot clear a patient for the next dose.
Do not assume a neurological event is definitely ARIA or definitely an ordinary stroke from a short vignette. The urgent clinical assessment must consider the differential and the anti-amyloid treatment history. Preserve the medicine, route, timing and imaging history for the treating team.
A worked case
A patient approaching the third IV lecanemab dose has only a pretreatment MRI on file. An old checklist starts repeat imaging before dose five. A different patient receives weekly subcutaneous doses. What needs correction?
- Use the current label, not the older dose-five-only checklist.
- At the one-month checkpoint, identify before IV dose three or subcutaneous dose five as the label examples.
- Ensure the MRI is reviewed before the scheduled dose and preserve the later month-based checks.
Answer: The route and current month-based monitoring schedule must replace the incomplete old checklist.
Try it before reading the answer
Write the key fact, decision and safety check first. These are original practice exercises, not recalled exam items.
1. Does no headache make scheduled MRI unnecessary?
No. ARIA can be asymptomatic.
2. Can an IV dose number be copied unchanged to weekly subcutaneous dosing?
No. Use the route-specific examples and actual treatment timeline.
3. Should new confusion wait until the routine scan?
No. It requires clinical assessment, with MRI if indicated under the label.
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Source dates and limits matter. Follow the current official source for clinical or regulatory decisions. Examples are simplified teaching cases, not prescribing, diagnostic or compounding instructions. Check the full current guidance and individual clinical context.