What the FDA labels say about taking them together
Isocarboxazid and levodopa
Isocarboxazid's FDA label of April 21, 2026 names levodopa in its contraindications section; levodopa's label does not name isocarboxazid itself but warns about its class (MAO inhibitors).
Check it at the source: the isocarboxazid FDA label on DailyMed (effective April 21, 2026, Lifsa Drugs LLC); the levodopa FDA label on DailyMed (effective July 20, 2026, Merz Pharmaceuticals, LLC).
What does the isocarboxazid label say about levodopa?
Isocarboxazid label, contraindicationsUse of sympathomimetics and compounds such as guanethidine, methyldopa, methylphenidate, reserpine, epinephrine, norepinephrine, phenylalanine, dopamine, levodopa, tyrosine, and tryptophan with Marplan may precipitate hypertension, headache, and related symptoms.
Source: FDA drug label (MARPLAN), Lifsa Drugs LLC, effective April 21, 2026 (SPL set 95fde749-44ad-4668-86c4-0ff17bca0074), via openFDA; the full label on DailyMed
What does the levodopa label say about isocarboxazid?
Levodopa's label does not name isocarboxazid itself; it warns about its class (MAO inhibitors):
Levodopa label, contraindicationsCONTRAINDICATIONS INBRIJA is contraindicated in patients currently taking a nonselective monoamine oxidase (MAO) inhibitor (e.g., phenelzine and tranylcypromine) or who have recently (within 2 weeks) taken a nonselective MAO inhibitor.
Levodopa label, drug interactionsOxidase (MAO) Inhibitors The use of nonselective MAO inhibitors with INBRIJA is contraindicated [see Contraindications (4) ].
Source: FDA drug label (Inbrija), Merz Pharmaceuticals, LLC, effective July 20, 2026 (SPL set 077c0f39-a3a2-4b2b-a184-09131889dcfb), 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
| Isocarboxazid | Levodopa | |
|---|---|---|
| Labeled for | Depression | Parkinson's disease |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | n/a | n/a |
| Shortage now | In shortage | 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