What the FDA labels say about taking them together
Drospirenone/ethinyl estradiol/levomefolate and phenobarbital
Drospirenone/ethinyl estradiol/levomefolate's FDA label of March 4, 2026 names phenobarbital in its drug interactions section; the phenobarbital labels PlainMeds reads (2) do not name drospirenone/ethinyl estradiol/levomefolate. The drospirenone/ethinyl estradiol/levomefolate label: “Drugs on Folates Several drugs have been reported to reduce folate concentrations by inhibition of the dihydrofolate reductase enzyme or by reducing folate absorption (e.g., cholestyramine), or via unknown mechanisms.”
Check it at the source: the drospirenone/ethinyl estradiol/levomefolate FDA label on DailyMed (effective March 4, 2026, Bayer HealthCare Pharmaceuticals Inc.); the phenobarbital FDA label on DailyMed (effective August 27, 2026).
What does the drospirenone/ethinyl estradiol/levomefolate label say about phenobarbital?
Drospirenone/ethinyl estradiol/levomefolate label, drug interactionsDrugs on Folates Several drugs have been reported to reduce folate concentrations by inhibition of the dihydrofolate reductase enzyme (e.g., methotrexate and sulfasalazine) or by reducing folate absorption (e.g., cholestyramine), or via unknown mechanisms (e.g., antiepileptics such as carbamazepine, phenytoin, phenobarbital, primidone and valproic acid).
Source: FDA drug label (Safyral), Bayer HealthCare Pharmaceuticals Inc., effective March 4, 2026 (SPL set 97563516-306a-4e17-9690-edbda49ecd83), via openFDA; the full label on DailyMed
What does the phenobarbital label say about drospirenone/ethinyl estradiol/levomefolate?
Phenobarbital's label (effective August 27, 2026) and its 1 other brand-application label do not name drospirenone/ethinyl estradiol/levomefolate in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Phenobarbital), Chartwell RX, LLC, effective August 27, 2026 (SPL set 74428144-fb24-40a5-a670-3b876e2d116c), 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
| Drospirenone/ethinyl estradiol/levomefolate | Phenobarbital | |
|---|---|---|
| Labeled for | Birth control, Acne | Seizures and epilepsy |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $1.38 per unit 3-0.02-0.451 | $0.213 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