The short answer
Tyramine-rich foods can provoke a blood-pressure reaction in some people taking isoniazid. The label advises avoiding tyramine-containing foods; case reports support the concern without defining a safe tyramine dose.
What this answer covers
Dietary tyramine exposure, including aged cheese; purified supplements and food concentrations differ.
- Supplement or preparation
- Tyramine
- Medication ingredient
- isoniazid
The label identifies the food interaction
Isoniazid has some monoamine-oxidase-inhibiting activity. Its label warns about tyramine-containing foods, separately from histamine-containing fish reactions.
The original cases involved cheese
Two patients developed paroxysmal hypertension after gruyere cheese during isoniazid treatment. The report supports a possible interaction, but did not measure a precise tyramine dose or the likelihood of a reaction.
Tyramine and histamine are different
The label also describes histamine-related symptoms, sometimes including low blood pressure. Those reactions should not be used as proof that tyramine invariably causes hypertension.
Follow food advice and seek help for severe symptoms
Discuss dietary restrictions with the TB clinician. Do not self-test a tyramine supplement or rely on dose spacing. A sudden severe headache, chest pain or marked blood-pressure symptoms require urgent assessment.
Evidence and practical considerations
Side effects & toxicity
Exact label and original cheese-associated hypertension cases support conditional tyramine pressor concern. Dietary content, individual susceptibility and histamine distinction retained; no measured safe dose or pair incidence.
- Exact scope
- Dietary tyramine exposure, including aged cheese; purified supplements and food concentrations differ. with Isoniazid oral tablets.
- Medication form and route
- oral medication; oral supplement
What remains uncertain
- No unmeasured pair incidence, blanket class transfer or arbitrary spacing interval.
Factors that may matter: Preparation; Dose; Other medicines; Organ function.
Read the supporting source summaries
Source 1: current product label
dailymed.nlm.nih.gov · Source check Sep 11, 2026
Population: People prescribed isoniazid
Hepatitis and peripheral-neuropathy warnings; pyridoxine recommended in predisposed patients; tyramine/histamine food precautions.
How this applies: Exact isoniazid RxCUI 6038 IN, with stated salt/formulation/route bridge.
Exact route and formulation apply. Label precautions do not quantify untested botanical pairs or support arbitrary supplement doses.
Source 2: Original human study
pubmed.ncbi.nlm.nih.gov · Source check Sep 11, 2026
Population: Two patients.
Paroxysmal hypertension in two patients; did not recur under reported similar conditions after stopping isoniazid.
How this applies: Case reports; tyramine content not quantified, no purified-dose threshold or universal event rate.
Case reports; tyramine content not quantified, no purified-dose threshold or universal event rate.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Research summary published | |
| Article prepared | |
| Prepared exact isoniazid article with formulation-specific evidence and uncertainty. |
Article revision: 5cef0d59eb894612
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.