Stavudine and Didanosine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Didanosine
Stavudine
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.
What happens
Increased risk of lactic acidosis, hepatotoxicity, peripheral neuropathy, and pancreatitis
Interaction Deep Dive
Concomitant use of didanosine and stavudine is contraindicated due to the increased risk of serious and life-threatening adverse events including lactic acidosis, hepatotoxicity, peripheral neuropathy, and pancreatitis1. In 2 drug interaction studies, coadministration had no significant effects on the pharmacokinetics of either agent 12. However, there has been cases of fatalities due to pancreatitis, hepatic events, and lactic acidosis with coadministration of didanosine and stavudine 1.
Why it happens (mechanism)
Unknown
Literature reports
5 reports — tap to read
a) Cases of fatal lactic acidosis has been reported in pregnant women coadministered stavudine and didanosine with other antiretroviral agents 1.
b) Cases of fatal hepatic events have been reported in patients treated with the combination of hydroxyurea, didanosine, and stavudine 1.
c) Cases of fatal and nonfatal pancreatitis have been reported with the coadministration of stavudine and a combination regimen that included didanosine in both treatment-naive and treatment-experienced patients, regardless of degree of immunosuppression 1.
d) In a drug interaction study of HIV-infected patients (n=10), stavudine Cmax was increased by 17% when a buffered formulation of didanosine 100 mg every 12 hours for 4 days was coadministered with stavudine 40 mg every 12 hours for 4 days. There was no pharmacokinetic effect on didanosine 1.
e) In an open, crossover design study, 10 adult male patients with HIV received single doses of stavudine 40 mg or didanosine 100 mg on days 1 and 2 of the study. Starting on day 3, both drugs were administered simultaneously every 12 hours for nine doses. No significant changes in Cmax, AUC, elimination half-life, or renal clearance were observed for either didanosine or stavudine 2.
Common questions
Can I take Stavudine and Didanosine together?
Increased risk of lactic acidosis, hepatotoxicity, peripheral neuropathy, and pancreatitis Always confirm with your pharmacist or prescriber before making any change.
How serious is the Stavudine and Didanosine interaction?
It is rated contraindicated. These should generally not be used together.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How strong is the evidence for this interaction?
The evidence is graded "established". Well documented — supported by controlled studies or strong clinical data.
Questions for your pharmacist
- Does my dose of Stavudine or Didanosine 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 (2)
- Product Information: ZERIT(R) oral capsules, solution, stavudine oral capsules, solution. Bristol-Myers Squibb Company (per FDA), Princeton, NJ, 2017. DailyMed
- Seifert RD, Stewart MB, Sramek JJ, et al: Pharmacokinetics of co-administered didanosine and stavudine in HIV-seropositive male patients. Br J Clin Pharmacol 1994; 38:405-410. PubMed
Keep reading about Didanosine
Keep reading about Stavudine
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
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