What the FDA labels say about taking them together
Methylergonovine and ritonavir
Methylergonovine's FDA label of May 1, 2026 names ritonavir in its drug interactions section, and ritonavir's label names methylergonovine too. The ritonavir label: “Contraindicated due to potential for acute ergot toxicity characterized by vasospasm and ischemia of the extremities and other tissues including the central nervous system.”
Check it at the source: the methylergonovine FDA label on DailyMed (effective May 1, 2026, Teva Pharmaceuticals USA, Inc.); the ritonavir FDA label on DailyMed (effective July 23, 2026, AbbVie Inc.).
What does the methylergonovine label say about ritonavir?
Methylergonovine label, drug interactionsAlthough there have been no reports of such interactions with methylergonovine alone, strong and moderate CYP 3A4 inhibitors should not be coadministered with methylergonovine. Examples of some of the strong CYP 3A4 inhibitors include saquinavir, grapefruit juice, nefazodone, macrolide antibiotics (e.g., troleandomycin, clarithromycin), HIV protease or reverse transcriptase inhibitors (e.g., ritonavir, indinavir, nelfinavir) or azole antifungals (e.g., ketoconazole, itraconazole, voriconazole). Moderate inhibitors include fluconazole, fluvoxamine and clotrimazole.
Source: FDA drug label (Methylergonovine Maleate), Teva Pharmaceuticals USA, Inc., effective May 1, 2026 (SPL set d8e4b8ed-3289-4611-8a61-2392a4bf6072), via openFDA; the full label on DailyMed
What does the ritonavir label say about methylergonovine?
Ritonavir label, contraindicationsNORVIR is contraindicated with drugs that are highly dependent on CYP3A for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening reactions [see Drug Interactions ( 7.1 ) and Clinical Pharmacology ( 12.3 )]. ○ Alpha 1- Adrenoreceptor Antagonist: alfuzosin ○ Antianginal: ranolazine ○ Antiarrhythmics: amiodarone, dronedarone, flecainide, propafenone, quinidine ○ Antifungal: voriconazole ○ Anti-gout: colchicine ○ Antipsychotics: lurasidone, pimozide ○ Ergot Derivatives: dihydroergotamine, ergotamine, methylergonovine ○ GI Motility Agent: cisapride ○ HMG-CoA Reductase Inhibitors: lovastatin, simvastatin ○ Microsomal triglyceride transfer …
Ritonavir label, drug interactionsConcomitant Drug Class/Drug Name: Ergot Derivatives: dihydroergotamine, ergotamine, methylergonovine; Effect on Concentration of Ritonavir or Concomitant Drug: ↑ ergot derivatives; Clinical Comment: Contraindicated due to potential for acute ergot toxicity characterized by vasospasm and ischemia of the extremities and other tissues including the central nervous system [see Contraindications () ].
Source: FDA drug label (Norvir), AbbVie Inc., effective July 23, 2026 (SPL set 2849298e-de6e-47bb-8194-56e075b33fc3), 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
| Methylergonovine | Ritonavir | |
|---|---|---|
| Labeled for | n/a | HIV |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $4.50 per tablet 0.2 mg tablet | $0.607 per tablet 100 mg tablet |
| Shortage now | No current entry | A presentation being discontinued |
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