Ribavirin and Didanosine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Ribavirin
Didanosine
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 didanosine-mediated mitochondrial toxicity, resulting in fatal or nonfatal lactic acidosis, fatal hepatic failure, peripheral neuropathy, or pancreatitis
Interaction Deep Dive
Administration of didanosine and ribavirin has resulted in fatal and nonfatal lactic acidosis, fatal hepatic failure, peripheral neuropathy and pancreatitis21. The concomitant administration of ribavirin with an established regimen of didanosine produced a significant increase in the incidence of didanosine-related toxicity in a cohort of HIV-infected patients diagnosed with hepatitis C viral infection 3. Concomitant administration of ribavirin and didanosine is not recommended 321.
Why it happens (mechanism)
Increased exposure to didanosine or its active metabolite (dideoxyadenosine 5'-triphosphate)
Literature reports
1 report — tap to read
a) The concomitant administration of ribavirin with an established regimen of didanosine produced a significant increase in the incidence of didanosine-related toxicity. In a longitudinal cohort study, HIV-infected patients (n=35) receiving didanosine-containing HAART regimens prior to initiating ribavirin were monitored for hepatotoxicity and pancreatic toxicity before and during ribavirin (and peginterferon) therapy for treatment of hepatitis C infection. Patients had been receiving didanosine for a mean of 22 months (range, 4-55 months) prior to receiving ribavirin therapy. While 11% percent of patients experienced didanosine-related toxicity prior to initiating hepatitic C treatment, over a period of 30 months, 20 patients (57%) experienced didanosine-related toxicity after initiating ribavirin therapy. Toxicity developed a mean of 87 days after starting coadministration. Eighteen patients (51%) developed increased amylase serum concentrations. Whereas 8 patients (23%) developed asymptomatic hyperamylasemia, the other 10 patients (28%) manifested signs and symptoms of clinically significant pancreatitis. Fourteen patients (40%) experienced a magnitude of toxicity that required withdrawal of didanosine, and one patient required a reduction in didanosine dose. Two cases of pancreatitis proved fatal; however, full recovery from toxicity occurred in all other affected patients 3.
Common questions
Can I take Ribavirin and Didanosine together?
Increased risk of didanosine-mediated mitochondrial toxicity, resulting in fatal or nonfatal lactic acidosis, fatal hepatic failure, peripheral neuropathy, or pancreatitis Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ribavirin 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 Ribavirin 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 (3)
- Product Information: VIDEX EC(R) delayed release oral capsules, enteric coated beadlets, didanosine delayed release oral capsules, enteric coated beadlets. Bristol-Myers Squibb Company, Princeton, NJ, 2009.
- Product Information: VIDEX(R) pediatric powder for oral solution, didanosine pediatric powder for oral solution. Bristol-Myers Squibb Company, Princeton, NJ, 2009.
- Moreno A, Quereda C, Moreno L, et al: High rate of didanosine-related mitochondrial toxicity in HIV/HCV-coinfected patients receiving ribavirin. Antivir Ther 2004; 9:133-138. DOI
Keep reading about Ribavirin
Keep reading about Didanosine
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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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