Metyrosine: uses, dosing, side effects & brands
Metyrosine is a catecholamine synthesis inhibitor sold in the U.S. under one brand, for pheochromocytoma. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Drug class
- Catecholamine Synthesis Inhibitor
- Treats
- Pheochromocytoma
- Available as
- Capsule
- Sold as
- Demser
- Prescription?
- Prescription only
- Generic available?
- Not in our catalog
How metyrosine is dosed
From the FDA label for Demser (application NDA017871). Other metyrosine products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
The recommended initial dosage of DEMSER for adults and children 12 years of age and older is 250 mg orally four times daily. This may be increased by 250 mg to 500 mg every day to a maximum of 4 g/day in divided doses. When used for preoperative preparation, the optimally effective dosage of DEMSER should be given for at least five to seven days. Optimally effective dosages of DEMSER usually are between 2 and 3 g/day, and the dose should be titrated by monitoring clinical symptoms and catecholamine excretion. In patients who are hypertensive, dosage should be titrated to achieve normalization of blood pressure and control of clinical symptoms. In patients who are usually normotensive, dosage should be titrated to the amount that will reduce urinary metanephrines and/or vanillylmandelic acid by 50% or more. If patients are not adequately controlled by the use of DEMSER, an alpha-adrenergic blocking agent (phenoxybenzamine) should be added. Use of DEMSER in children under 12 years of age has been limited and a dosage schedule for this age group cannot be given.
Metyrosine side effects
Central Nervous System Sedation: The most common adverse reaction to DEMSER is moderate to severe sedation, which has been observed in almost all patients. It occurs at both low and high dosages. Sedative effects begin within the first 24 hours of therapy, are maximal after two to three days, and tend to wane during the next few days. Sedation usually is not obvious after one week unless the dosage is increased, but at dosages greater than 2000 mg/day some degree of sedation or fatigue may persist. In most patients who experience sedation, temporary changes in sleep pattern occur following withdrawal of the drug. Changes consist of insomnia that may last for two or three days and feelings of increased alertness and ambition. Even patients who do not experience sedation while on DEMSER may report symptoms of psychic stimulation when the drug is discontinued. Extrapyramidal Signs: Extrapyramidal signs such as drooling, speech difficulty, and tremor have been reported in approximately 10% of patients. These occasionally have been accompanied by trismus and frank parkinsonism. Anxiety and Psychic Disturbances: Anxiety and psychic disturbances such as depression, hallucinations, disorientation, and confusion may occur. These effects seem to be dose-dependent and may disappear with reduction of dosage. Diarrhea Diarrhea occurs in about 10% of patients and may be severe.…
Who shouldn’t take metyrosine
DEMSER is contraindicated in persons known to be hypersensitive to this compound.
Every metyrosine product we track (1)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
Only one: Demser.
What metyrosine pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
| Imprint | Strength | Colour | Shape | Maker |
|---|---|---|---|---|
| AA;05A | 250 mg | blue | capsule | — |
| 315;C | 250 mg | blue | capsule | — |
| Aton;305;DEMSER | 250 mg | blue | capsule | — |
| Aton;305;DEMSER | 250 mg | blue | capsule | — |
| AA;05A | 250 mg | blue | capsule | — |
What people report to the FDA about metyrosine
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 17 reports naming metyrosine, and the FDA flagged 82% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- hypotension3 reports
- catecholamine crisis2 reports
- dizziness2 reports
- pyrexia2 reports
- vomiting2 reports
- acute myocardial infarction1 reports
- acute respiratory distress syndrome1 reports
- administration site extravasation1 reports
Read these as a signal, not a rate. A report does not mean metyrosine caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 25, 2026.
Related calculators
Frequently asked questions
What is metyrosine?
Demser (Metyrosine) is a catecholamine synthesis inhibitor used to treat Pheochromocytoma.
What kind of drug is metyrosine?
The FDA classifies metyrosine as a catecholamine synthesis inhibitor. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take metyrosine with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run metyrosine against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What forms does metyrosine come in?
Across the brands we track, metyrosine is currently marketed as capsule, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic metyrosine?
We do not currently list a generic-labelled metyrosine product. That does not always mean none exists — it means none appears under a generic name in the FDA data we track. Ask your pharmacist.
Cite this page
- APA
- pharmaranks. (2026, July 24). Metyrosine: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/metyrosine
- MLA
- “Metyrosine: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/metyrosine.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for metyrosine on DailyMed (NIH) ↗.