What the FDA labels say about taking them together
Isosorbide mononitrate and tadalafil
Isosorbide mononitrate's FDA label (Isosorbide Mononitrate) of August 6, 2025 names tadalafil in its contraindications section; tadalafil's label does not name isosorbide mononitrate itself but warns about its class (nitrate vasodilators). The isosorbide mononitrate label: “Do not use isosorbide mononitrate in patients who are taking certain drugs for erectile dysfunction, such as sildenafil, tadalafil, or vardenafil.”
Check it at the source: the isosorbide mononitrate FDA label on DailyMed (effective May 11, 2026, Torrent Pharmaceuticals Limited); the tadalafil FDA label on DailyMed (effective June 3, 2026, Eli Lilly and Company).
What does the isosorbide mononitrate label say about tadalafil?
Isosorbide Mononitrate label (OMNIVIUM PHARMACEUTICALS LLC., August 6, 2025), contraindicationsDo not use isosorbide mononitrate in patients who are taking certain drugs for erectile dysfunction (phosphodiesterase inhibitors), such as sildenafil, tadalafil, or vardenafil.
Source: FDA drug label (Isosorbide Mononitrate, NDA020215), OMNIVIUM PHARMACEUTICALS LLC., effective August 6, 2025 (SPL set cdf01e14-778b-4b3f-8372-1c18f266fb98), via openFDA
Source: FDA drug label (ISOSORBIDE MONONITRATE), Torrent Pharmaceuticals Limited, effective May 11, 2026 (SPL set 0a1e317a-7b05-4d30-9bbc-1d4ccd56ba3c), via openFDA; the full label on DailyMed
What does the tadalafil label say about isosorbide mononitrate?
Tadalafil's label does not name isosorbide mononitrate itself; it warns about its class (nitrate vasodilators):
Tadalafil label, contraindicationsCONTRAINDICATIONS Administration of CIALIS to patients using any form of organic nitrate is contraindicated.
Tadalafil label, contraindicationsAdministration of CIALIS to patients who are using any form of organic nitrate, either regularly and/or intermittently, is contraindicated.
Source: FDA drug label (Cialis), Eli Lilly and Company, effective June 3, 2026 (SPL set bcd8f8ab-81a2-4891-83db-24a0b0e25895), 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
| Isosorbide mononitrate | Tadalafil | |
|---|---|---|
| Labeled for | Angina | Erectile dysfunction, Enlarged prostate (BPH), Pulmonary arterial hypertension |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.0688 per tablet 30 mg tablet | $0.167 per tablet 20 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