Drug interactions
Isoniazid + Sodium bicarbonate
Severity: Moderate
Isoniazid and Sodium bicarbonate: 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
Antacids and alkalinizing agents may reduce the oral absorption of isoniazid, lowering serum concentrations. Subtherapeutic levels could reduce efficacy and favor resistance.
What this interaction means in plain words
Isoniazid and Sodium bicarbonate 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 belongs to Anti Bacterial; Sodium bicarbonate belongs to Gastrointestinal Tract.
Why it happens
Raised gastric pH and possible binding reduce isoniazid absorption.
What to do
Give isoniazid at least 2 hours apart from oral sodium bicarbonate, preferably on an empty stomach. Reassess treatment response if antacid use is frequent.
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
Other interactions of Sodium bicarbonate
- Acetylsalicylic acid + Sodium bicarbonate Moderate
- Alendronate + Sodium bicarbonate Moderate
- Amantadine + Sodium bicarbonate Moderate
- Carbonyl iron + Sodium bicarbonate Moderate
- Cefditoren + Sodium bicarbonate Moderate
- Cefpodoxime + Sodium bicarbonate Moderate
Frequently asked questions
Can I take Isoniazid with Sodium bicarbonate?
MediHelp rates the interaction as moderate. Isoniazid and Sodium bicarbonate 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. Antacids and alkalinizing agents may reduce the oral absorption of isoniazid, lowering serum concentrations. Subtherapeutic levels could reduce efficacy and favor resistance.
How serious is the interaction between Isoniazid and Sodium bicarbonate?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Give isoniazid at least 2 hours apart from oral sodium bicarbonate, preferably on an empty stomach. Reassess treatment response if antacid use is frequent.
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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