What the FDA labels say about taking them together
Tamsulosin and terbinafine
Tamsulosin's FDA label of December 1, 2025 names terbinafine in its drug interactions section; the terbinafine label PlainMeds reads does not name tamsulosin. The tamsulosin label: “… erythromycin), in combination with strong (e.g., paroxetine) or moderate (e.g., terbinafine) inhibitors of CYP2D6, or in patients known to be CYP2D6 poor metabolizers, particularly at a dose higher than 0.4 mg (e.g. …”
Check it at the source: the tamsulosin FDA label on DailyMed (effective December 1, 2025, Synthon Pharmaceuticals, Inc.); the terbinafine FDA label on DailyMed (effective October 17, 2025, PD-Rx Pharmaceuticals, Inc.).
What does the tamsulosin label say about terbinafine?
Tamsulosin label, drug interactionsTamsulosin hydrochloride capsules should be used with caution in combination with moderate inhibitors of CYP3A4 (e.g., erythromycin), in combination with strong (e.g., paroxetine) or moderate (e.g., terbinafine) inhibitors of CYP2D6, or in patients known to be CYP2D6 poor metabolizers, particularly at a dose higher than 0.4 mg (e.g., 0.8 mg). ( 5.2 , 7.1 , 12.3 ) Concomitant use of PDE5 inhibitors with tamsulosin can potentially cause symptomatic hypotension
Source: FDA drug label (Tamsulosin hydrochloride), Synthon Pharmaceuticals, Inc., effective December 1, 2025 (SPL set 13a5032d-0be1-4001-916e-459f0b1a051d), via openFDA; the full label on DailyMed
What does the terbinafine label say about tamsulosin?
Terbinafine's label (effective October 17, 2025) does not name tamsulosin in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Terbinafine Hydrochloride), PD-Rx Pharmaceuticals, Inc., effective October 17, 2025 (SPL set 2df111dc-ecac-4161-9e22-38436eb37c1f), 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
| Tamsulosin | Terbinafine | |
|---|---|---|
| Labeled for | Enlarged prostate (BPH) | Fungal infections |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.05 per capsule 0.4 mg capsule | $0.143 per tablet 250 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