Does cytarabine expire?
The printed date covers the sealed pack. Once cytarabine is opened, mixed or diluted, its label sets a second and usually much shorter limit — quoted below, per product.
Shortest limit on any cytarabine label: 4 hours
“Discard any unused portion within 4 hours after initial closure entry.”
That applies to the product it is printed on, not to every form of cytarabine — check which one you have against the list below.
What the labels say
“Discard any unused portion within 4 hours after initial closure entry.”
On the label for Cytarabine · DailyMed
How the label says to keep cytarabine
Storage is the other half of the question: the stability behind any date assumes these conditions, and a medicine kept outside them ages faster than the calendar says.
- “Conditions Store at 20° to 25°C (68° to 77°F); excursions permitted between 15° and 30°C (59° and 86°F).”
- “Protect from light.”
- “tion or Sodium Chloride Injection, in both glass and plastic infusion bags, 97 to 100% of the cytarabine was present after 8 days storage at room temperature.”
- “Store at 20°C to 25°C (68°F to 77°F) [USP Controlled Room Temperature].”
- “Water for Injection, 5% Dextrose Injection or Sodium Chloride Injection, 97-100% of the cytarabine was still present after 8 days storage at room temperature.”
- “for Injection, 5% Dextrose in Water or Sodium Chloride Injection, 94 to 96 percent of the cytarabine was present after 192 hours storage at room temperature.”
- “jection or Sodium Chloride Injection, in both glass and plastic infusion bags, 97-100% of the cytarabine was present after 8 days storage at room temperature.”
- “Store at 20º to 25ºC (68º to 77ºF) [USP Controlled Room Temperature].”
Frequently asked questions
Does cytarabine expire?
Two different clocks apply and only one of them is the printed date. The date on a sealed pack is the manufacturer's guarantee for the unopened product. Once it is opened, mixed or diluted, the label imposes its own limit — as tight as 4 hours on some cytarabine products, and that is the number quoted on this page.
Can I still use cytarabine after the date on the box?
This page cannot tell you that, and nor can any page. The FDA's own shelf-life programme found 88% of tested lots stayed within specification at least a year past expiry — and concluded in the same breath that lot-to-lot variation means this can only be confirmed by testing each lot. What you can check at home is the in-use limit above and whether the product has been stored as the label requires. Ask a pharmacist about a specific pack; they will also dispose of what you no longer need.
Why do different cytarabine products have different limits?
Because they are different formulations. A suspension that gets mixed with water, a pen that gets carried at room temperature, and a sealed tablet do not behave alike, so each manufacturer's label sets its own limit and each is shown here with the product it belongs to. We never merge them into one number for the molecule.
More on cytarabine
Quoted from FDA labels for reference, not medical advice, and not a suggestion to use anything past its limit. If you are unsure whether a pack is still good, a pharmacist can tell you and can dispose of it safely.