Meta Information
ID:niacin
Name:
Schema Version:2.4_uniform_evidence_2026_06_18
Created
2026-05-21T22:30:00Z
Model
phase-a-upgrade-claude-sonnet-4.6
Interactions
Target id:
/class/statins
Target name:
Statins (HMG-CoA Reductase Inhibitors)
Severity:
major
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Both niacin and statins can cause muscle damage (myopathy). When taken together, this risk is significantly increased, potentially leading to a severe condition called rhabdomyolysis.
Actionable advice:
This combination should be avoided unless specifically prescribed and closely monitored by a physician for muscle pain or weakness.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
7 DRUG INTERACTIONS Statins: Caution should be used when prescribing niacin with statins as these agents can increase risk of myopathy/rhabdomyolysis.
Label source:
Action type:
avoid
Target id:
/class/hepatotoxic-agents
Target name:
Hepatotoxic Agents
Severity:
major
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Niacin, particularly in sustained-release formulations, can be stressful to the liver. Combining it with other substances known to harm the liver (like certain drugs or excessive alcohol) significantly increases the risk of liver injury.
Actionable advice:
Other potentially liver-toxic agents should not be combined, and alcohol consumption should be strictly limited.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Although mode of liver injury remains unknown, the use of extended-release niacin formulations and prolonged high-dose supplementation is associated with enhanced hepatotoxicity.
Label source:
PubMed: Cholestatic Drug-Induced Liver Injury in a Patient Taking High-Dose Niacin for Hyperlipidemia. (PMID 38193433)
Action type:
avoid
Target id:
/condition/hepatic-impairment
Target name:
Hepatic Impairment
Severity:
major
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Niacin is metabolized by the liver and can cause or worsen liver damage. It is generally contraindicated in patients with active or unexplained liver dysfunction.
Actionable advice:
High-dose niacin should not be taken in active liver disease; regular liver function monitoring is required for all users.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
( 5 , 8.6 ) Hepatic impairment: Niacin extended-release tablets are contraindicated in active liver disease or significant or unexplained hepatic dysfunction or unexplained elevations of serum transaminases.
Label source:
Action type:
avoid
Target id:
/condition/peptic-ulcer-disease
Target name:
Peptic Ulcer Disease (PUD)
Severity:
major
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Niacin can increase stomach acid secretion and may reactivate a dormant peptic ulcer, leading to pain, discomfort, or bleeding.
Actionable advice:
High-dose niacin should be avoided with an active peptic ulcer.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
4 CONTRAINDICATIONS Niacin extended-release tablets are contraindicated in the following conditions: • Active liver disease or unexplained persistent elevations in hepatic transaminases [see Warnings and Precautions ( 5.3 )] • Patients with active peptic ulcer disease • Patients with arterial bleeding • Hypersensitivity to niacin or any component of this medication [see Adverse Reactions ( 6.1 )] Active liver disease, which may include unexplained persistent elevations in hepatic transaminase levels.
Label source:
Action type:
avoid
Target id:
/class/fibrates
Target name:
Fibrates
Severity:
major
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Both niacin and fibrates can cause muscle damage (myopathy). The combined use significantly elevates this risk, similar to the interaction with statins.
Actionable advice:
This combination should be avoided unless under strict medical supervision due to a high risk of severe muscle damage.
Validation status:
validated_via_pubmed
Evidence tier:
tier_b
Evidence basis:
pubmed_abstract_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Of particular concern is the potential for interactions with other lipid-lowering agents such as fibrates and niacin (nicotinic acid), which may be used in patients with mixed lipidemia, and with immunosuppressive agents, such as cyclosporine, which are commonly used in patients after transplantation.
Label source:
PubMed: Archives of internal medicine (2003)
Source url:
Exact phrase from label:
Combination of statin/fibrate or statin/niacin increase the risk of myopathy.
Label source:
PubMed: Tidsskrift for den Norske laegeforening : tidsskrift for praktisk medicin, ny raekke (2004)
Action type:
avoid
Target id:
/class/bile-acid-sequestrants
Target name:
Bile Acid Sequestrants & Binders
Severity:
moderate
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
1
Hours after target:
4
Description:
Bile acid sequestrants can bind to niacin in the gut, preventing its full absorption and reducing its effectiveness.
Actionable advice:
Niacin is best taken at least 1 hour before or 4 hours after a bile acid sequestrant.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
7.2 Bile Acid Sequestrants An in vitro study results suggest that the bile acid-binding resins have high niacin binding capacity.
Label source:
Action type:
separate
Target id:
/class/antihypertensives
Target name:
Antihypertensive Medications
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Niacin causes blood vessels to widen (vasodilation), which can add to the effect of blood pressure medications, potentially leading to dizziness, lightheadedness, or fainting from low blood pressure.
Actionable advice:
Blood pressure should be monitored closely when starting or increasing the dose of niacin while on antihypertensive drugs.
Validation status:
validated_via_pubmed
Evidence tier:
tier_b
Evidence basis:
pubmed_abstract_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Acute administration of immediate-release niacin may lower BP because of niacin's acute vasodilatory effects. Although not always supported by clinical trial data, the package insert of a prescription, extended-release niacin describes niacin-induced acute hypotension.
Label source:
PubMed: International journal of clinical practice (2009)
Source url:
Exact phrase from label:
We describe a case of massive oral niacin overdose that resulted in severe persistent hypotension without the manifestation of cutaneous flushing.
Label source:
PubMed: Clinical toxicology (Philadelphia, Pa.) (2006)
Source url:
Exact phrase from label:
Niacin-induced flushing occurs when the hydroxycarboxylic acid receptor 2 (HCA2 or GPR109A) is activated. This starts a signaling cascade that releases prostaglandins, especially PGD2, which causes cutaneous vasodilation.
Label source:
PubMed: Archives of biochemistry and biophysics (2024)
Action type:
monitor
Target id:
/class/antidiabetic-medications
Target name:
Diabetes Medications
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
High-dose niacin can impair glucose tolerance and raise blood sugar levels, potentially counteracting the effects of medications used to treat diabetes.
Actionable advice:
Blood glucose levels are best monitored carefully, as adjustments to diabetes medication may be needed under a doctor's guidance.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
5.4 Laboratory Abnormalities Increase in Blood Glucose: Niacin treatment can increase fasting blood glucose.
Label source:
Action type:
monitor
Target id:
/class/anticoagulants-antiplatelets
Target name:
Anticoagulants and Antiplatelets
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
High-dose niacin can have a mild effect on blood clotting. This may slightly increase the risk of bleeding when combined with anticoagulant or antiplatelet medications like warfarin or aspirin.
Actionable advice:
This is best used with caution and under medical supervision, with monitoring for any signs of increased bleeding or bruising.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Caution should be observed when niacin extended-release tablets are administered concomitantly with anticoagulants; platelet counts should be monitored closely in such patients.
Label source:
Action type:
monitor
Target id:
/condition/diabetes-mellitus
Target name:
Diabetes Mellitus
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
High-dose niacin can cause insulin resistance and raise blood sugar levels, making glycemic control more challenging for individuals with diabetes.
Actionable advice:
If you have diabetes, use niacin only under a doctor's supervision with frequent blood sugar monitoring.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
The major drawback in the use of niacin is associated side effects (flushing and palpitations) and toxicity (worsening of diabetes control, exacerbation of peptic ulcer disease, gout, hepatitis).
Label source:
PubMed: New developments in the use of niacin for treatment of hyperlipidemia: new considerations in the use of an old drug. (PMID 8853585)
Action type:
monitor
Target id:
/condition/gout
Target name:
Gout
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Niacin can increase serum uric acid levels by competing for excretion in the kidneys, which can trigger a painful gout attack in susceptible individuals.
Actionable advice:
Niacin is best used with caution in those with a history of gout, and it is a good idea to have uric acid levels monitored.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Increase in Uric Acid: Elevated uric acid levels have occurred with niacin therapy, therefore use with caution in patients predisposed to gout.
Label source:
Action type:
monitor
Target id:
/dietary/alcohol-acute
Target name:
Alcohol (Acute Consumption)
Severity:
moderate
Interaction type:
adverse
Nature:
temporal
Temporal spacing:
Hours before target:
2
Hours after target:
2
Description:
Alcohol can significantly worsen the flushing (redness, warmth, itching) caused by niacin. It also adds to the potential for liver stress when used with high-dose niacin.
Actionable advice:
Alcohol is best avoided for at least two hours before and after the niacin dose to reduce flushing and liver strain.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Diet Avoid ingestion of alcohol, hot beverages and spicy foods around the time of taking niacin extended-release tablets to minimize flushing.
Label source:
Action type:
separate
Target id:
/class/antioxidant-supplements
Target name:
Antioxidant Supplements (Vitamin C, E, Selenium)
Severity:
moderate
Interaction type:
diminishing
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Some clinical studies suggest that taking antioxidant supplements concurrently with niacin may blunt its beneficial effect of raising HDL ('good') cholesterol.
Actionable advice:
If your primary goal for taking niacin is to raise HDL, discuss the use of high-dose antioxidant supplements with your doctor.
Validation status:
anecdotal
Evidence tier:
tier_d
Evidence basis:
anecdotal_summary
Evidence anchors:
Exact phrase from label:
Taking vitamin E with cholesterol-lowering medicines called statins and niacin could keep niacin from working as it should.
Label source:
Anecdotal: Mayo Clinic
Action type:
informational_none
Target id:
/dietary/meal
Target name:
Any Caloric Meal
Severity:
moderate
Interaction type:
informational
Nature:
temporal
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Taking niacin with food slows its absorption, which can significantly reduce the severity of stomach upset and the intensity of the 'niacin flush'.
Actionable advice:
Niacin is best taken with a meal or a low-fat snack to improve tolerability.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Flushing, pruritus, and gastrointestinal distress are also greatly reduced by slowly increasing the dose of niacin and avoiding administration on an empty stomach.
Label source:
Action type:
informational_none
Target id:
/intervention/aspirin
Target name:
Aspirin (Low-Dose)
Severity:
moderate
Interaction type:
synergistic
Nature:
temporal
Temporal spacing:
Hours before target:
0.5
Hours after target:
null
Description:
A low dose of aspirin (e.g., 81-325mg) blocks the production of prostaglandins that cause the characteristic flushing, itching, and warmth associated with niacin.
Actionable advice:
To prevent the niacin flush, consider taking a low-dose aspirin 30 minutes before your niacin dose, after consulting your doctor.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Flushing of the skin [see Adverse Reactions ( 6.1 )] may be reduced in frequency or severity by pretreatment with aspirin (up to the recommended dose of 325 mg taken 30 minutes prior to niacin extended-release tablets dose).
Label source:
Action type:
informational_none
Target id:
/biomarker/alanine-aminotransferase
Target name:
Alanine Aminotransferase (ALT)
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
High-dose niacin, especially sustained-release forms, can cause an elevation in liver enzymes, which is a key marker for liver stress or damage.
Actionable advice:
Regular monitoring of liver function tests is essential before starting and during therapy with high-dose niacin.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Monitor liver enzymes before and during treatment.
Label source:
Action type:
monitor
Target id:
/biomarker/uric-acid
Target name:
Uric Acid
Severity:
moderate
Interaction type:
assay_interference
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Niacin can increase serum uric acid levels by reducing its excretion from the kidneys, which can be measured in a blood test.
Actionable advice:
Uric acid levels should be monitored periodically, especially with a personal or family history of gout.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Increase in Uric Acid: Elevated uric acid levels have occurred with niacin therapy, therefore use with caution in patients predisposed to gout.
Label source:
Action type:
monitor
Target id:
/biomarker/fasting-glucose
Target name:
Fasting Glucose
Severity:
moderate
Interaction type:
assay_interference
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Niacin can impair glucose tolerance and lead to a measurable increase in fasting blood sugar levels.
Actionable advice:
Fasting glucose and HbA1c should be monitored regularly, particularly in individuals with diabetes or metabolic syndrome.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Significant elevations of liver enzymes, serum glucose, and serum uric acid are occasionally seen with nicotinic acid therapy.
Label source:
PubMed: Adverse effects of hypolipidaemic drugs. (PMID 3547004)
Action type:
monitor
Target id:
/dietary/hot-foods-beverages
Target name:
Hot Beverages or Spicy Foods
Severity:
minor
Interaction type:
adverse
Nature:
temporal
Temporal spacing:
Hours before target:
1
Hours after target:
1
Description:
Hot liquids and spicy foods can also cause vasodilation and may trigger or worsen the flushing reaction caused by niacin.
Actionable advice:
Hot beverages or very spicy foods are generally best avoided around the time the niacin dose is taken.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Diet Avoid ingestion of alcohol, hot beverages and spicy foods around the time of taking niacin extended-release tablets to minimize flushing.
Label source:
Action type:
avoid
Target id:
/circadian/sleep
Target name:
Going to Sleep
Severity:
minor
Interaction type:
synergistic
Nature:
temporal
Temporal spacing:
Hours before target:
0.5
Hours after target:
null
Description:
Taking the niacin dose shortly before bedtime may allow the peak flushing symptoms to occur while you are asleep, improving overall comfort and adherence.
Actionable advice:
Consider taking your niacin dose with an evening snack just before going to bed to minimize awareness of the flush.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
By dosing at bedtime, flushing will most likely occur during sleep.
Label source:
Action type:
informational_none
Target id:
/biomarker/complete-blood-count
Target name:
Complete Blood Count
Severity:
minor
Interaction type:
assay_interference
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
In rare cases, high-dose niacin can cause a mild, dose-related reduction in platelet count (thrombocytopenia), which would be detected on a CBC.
Actionable advice:
This potential effect is worth keeping in mind; periodic monitoring with a complete blood count may be recommended by a doctor.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Reduction in platelet count: Niacin extended-release tablets have been associated with small but statistically significant dose-related reductions in platelet count (mean of -11% with 2000 mg).
Label source:
Action type:
monitor
Target id:
/condition/pregnancy
Target name:
Pregnancy
Severity:
major
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Doses of niacin above the standard recommended dietary allowance have not been established as safe during pregnancy and should be avoided.
Actionable advice:
High-dose niacin should not be taken during pregnancy unless specifically directed by a physician.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
8.1 Pregnancy Risk Summary Discontinue niacin extended-release tablets when pregnancy is recognized in patients receiving the drug for the treatment of hyperlipidemia.
Label source:
Action type:
avoid
Target id:
/condition/lactation
Target name:
Breastfeeding (Lactation)
Severity:
major
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
It is not known if high doses of niacin are excreted in breast milk or what effect they might have on a nursing infant; therefore, it should be avoided.
Actionable advice:
High-dose niacin should be avoided while breastfeeding.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Because of the potential for serious adverse reactions in breastfeeding infants, including hepatotoxicity, advise patients not to breastfeed during treatment with niacin extended-release tablets.
Label source:
Action type:
avoid