Drug interactions
Insulin nph + Niacin
Severity: Moderate
Insulin nph and Niacin: 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
Niacin, particularly at lipid-lowering doses, can impair glucose tolerance and raise blood glucose. This may reduce the effectiveness of NPH insulin and worsen glycemic control.
What this interaction means in plain words
Insulin nph and Niacin 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
Niacin induces insulin resistance and increases hepatic glucose output, pharmacodynamically opposing insulin action.
What to do
Monitor blood glucose more frequently when niacin is started, changed or stopped. Adjust the insulin dose as needed.
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 Niacin
- Alogliptin-metformin + Niacin Moderate
- Atorvastatin + Niacin Moderate
- Canagliflozin-metformin + Niacin Moderate
- Cholestyramine + Niacin Moderate
- Colestipol + Niacin Moderate
- Dapagliflozin-metformin + Niacin Moderate
Frequently asked questions
Can I take Insulin nph with Niacin?
MediHelp rates the interaction as moderate. Insulin nph and Niacin 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. Niacin, particularly at lipid-lowering doses, can impair glucose tolerance and raise blood glucose. This may reduce the effectiveness of NPH insulin and worsen glycemic control.
How serious is the interaction between Insulin nph and Niacin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood glucose more frequently when niacin is started, changed or stopped. Adjust the insulin dose as needed.
What other medicines interact with Niacin?
MediHelp also lists interactions of Niacin with, for example, Alogliptin-metformin, Atorvastatin, Canagliflozin-metformin. The full list is on the Niacin page.
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