What the FDA labels say about taking them together
Methadone and zidovudine
Methadone's FDA label of December 8, 2025 names zidovudine in its drug interactions section; the zidovudine labels PlainMeds reads (3) do not name methadone. The methadone label: “The concomitant use of anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.”
Check it at the source: the methadone FDA label on DailyMed (effective December 8, 2025, Epic Pharma, LLC); the zidovudine FDA label on DailyMed (effective February 10, 2025, Aurobindo Pharma Limited).
What does the methadone label say about zidovudine?
Methadone label, drug interactionsClinical Impact: The concomitant use of anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. … disposition was not substantially altered. Experimental evidence demonstrated that methadone increased the AUC of zidovudine, which could result in toxic effects. Effects of methadone hydrochloride tablets on Antidepressants Desipramine: Blood levels of desipramine have increased with concurrent methadone …
Source: FDA drug label (Diskets, NDA017058), Hikma Pharmaceuticals USA Inc., effective December 1, 2025 (SPL set e6af84de-cbfc-4a3b-bd73-6bcf77337168), via openFDA
Source: FDA drug label (Methadose, NDA017116), SpecGx LLC, effective April 27, 2026 (SPL set 808a9d0b-720b-4034-a862-5122ff514608), via openFDA
Source: FDA drug label (Methadone Hydrochloride, NDA021624), Mylan Institutional LLC, effective December 31, 2025 (SPL set 092d78eb-6423-495c-bf0d-e6532bea7138), via openFDA
Source: FDA drug label (Methadone Hydrochloride), Epic Pharma, LLC, effective December 8, 2025 (SPL set 6da7501b-b881-4bc7-891a-74214a00a3ac), via openFDA; the full label on DailyMed
What does the zidovudine label say about methadone?
Zidovudine's label (effective February 10, 2025) and its 2 other brand-application labels do not name methadone in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Zidovudine), Aurobindo Pharma Limited, effective February 10, 2025 (SPL set 51abd2ce-6be1-412d-b806-5f24935ac5e3), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Methadone | Zidovudine | |
|---|---|---|
| Labeled for | Pain, Opioid use disorder | HIV |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.177 per tablet 10 mg tablet | $0.464 per tablet 300 mg tablet |
| Shortage now | No current entry | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once