Drug interactions
Isoniazid + Lsd
Severity: Moderate
Isoniazid and Lsd: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Isoniazid has weak MAO inhibiting activity and LSD is a potent serotonergic agonist. Combining them could theoretically intensify serotonergic effects, though documented cases are lacking.
What this interaction means in plain words
Isoniazid and Lsd can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Theoretical additive serotonergic activity from weak MAO inhibition plus 5-HT2A receptor agonism.
What to do
Counsel patients to avoid LSD during isoniazid therapy. If exposure occurs, monitor for serotonin toxicity such as hyperthermia, clonus and autonomic instability.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Isoniazid
Frequently asked questions
Can I take Isoniazid with Lsd?
MediHelp rates the interaction as moderate. Isoniazid and Lsd can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Isoniazid has weak MAO inhibiting activity and LSD is a potent serotonergic agonist. Combining them could theoretically intensify serotonergic effects, though documented cases are lacking.
How serious is the interaction between Isoniazid and Lsd?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Counsel patients to avoid LSD during isoniazid therapy. If exposure occurs, monitor for serotonin toxicity such as hyperthermia, clonus and autonomic instability.
What other medicines interact with Isoniazid?
MediHelp also lists interactions of Isoniazid with, for example, Bacillus calmette-guerin substrain tice, Benzhydrocodone / acetaminophen, Carbamazepine. The full list is on the Isoniazid page.
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