What the FDA labels say about taking them together
Iobenguane i 123 and phenylephrine
Iobenguane i 123's FDA label of January 10, 2024 names phenylephrine in its drug interactions section; the phenylephrine labels PlainMeds reads (4) do not name iobenguane i 123. The iobenguane i 123 label: “If the AdreView imaging information is essential for clinical care, consider the withdrawal of the following categories of medications if the withdrawal can be accomplished safely: antihypertensives that deplete …”
Check it at the source: the iobenguane i 123 FDA label on DailyMed (effective January 10, 2024); the phenylephrine FDA label on DailyMed (effective August 19, 2026, Hikma Pharmaceuticals USA Inc.).
What does the iobenguane i 123 label say about phenylephrine?
Iobenguane i 123 label, drug interactionsDRUG INTERACTIONS The following drugs have the potential to decrease the uptake of norepinephrine and cause false negative imaging results: antihypertensives that deplete norepinephrine stores or inhibit reuptake (e.g., reserpine, labetalol), antidepressants that inhibit norepinephrine transporter function (e.g., amitriptyline and derivatives, imipramine and derivatives, selective serotonin reuptake inhibitors), sympathomimetic amines (e.g., phenylephrine, phenylpropanolamine, pseudoephedrine and ephedrine), and cocaine.
Iobenguane i 123 label, warnings and precautionsIf the AdreView imaging information is essential for clinical care, consider the withdrawal of the following categories of medications if the withdrawal can be accomplished safely: antihypertensives that deplete norepinephrine stores or inhibit reuptake (e.g., reserpine, labetalol), antidepressants that inhibit norepinephrine transporter function (e.g., amitriptyline and derivatives, imipramine and derivatives, selective serotonin reuptake inhibitors), and sympathomimetic amines (e.g., phenylephrine, phenylpropanolamine, pseudoephedrine and ephedrine).
Source: FDA drug label (AdreView), Medi-Physics Inc., effective January 10, 2024 (SPL set c89d3ecc-4f4c-4566-8808-79152344194d), via openFDA; the full label on DailyMed
What does the phenylephrine label say about iobenguane i 123?
Phenylephrine's label (effective August 19, 2026) and its 3 other brand-application labels do not name iobenguane i 123 in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Phenylephrine Hydrochloride), Hikma Pharmaceuticals USA Inc., effective August 19, 2026 (SPL set e1a7ab4b-0afe-4463-a039-5be0323cf2f7), 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
| Iobenguane i 123 | Phenylephrine | |
|---|---|---|
| Labeled for | n/a | Cough and cold, Allergies |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $5.24 per mL 10% eye drop |
| 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