Niacinamide 500mg Tablets
This vitamin is used to treat or prevent niacin deficiency.It may be given to you for other reasons. Talk with the doctor.
Drug Class
Vitamin, Nutritional Supplement
Pharmacologic Class
Water-soluble vitamin (B-complex vitamin), Nicotinamide
Pregnancy Category
Category A (at recommended daily allowance); Category C (at doses exceeding RDA)
FDA Approved
Jan 1970
DEA Schedule
Not Controlled
Overview
What is this medicine?
Niacinamide is a form of Vitamin B3, an essential nutrient that helps your body convert food into energy and supports healthy skin, nerves, and digestion. It's often used as a dietary supplement.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. Take this medication with food to help your body absorb it properly. When it's time to take your dose, avoid consuming alcohol, hot drinks, or spicy foods, as they may interfere with the medication's effectiveness.
Storing and Disposing of Your Medication
Keep your medication at room temperature in a dry place, away from the bathroom. Store all medications in a safe location, out of the reach of children and pets. When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so by your pharmacist. Instead, check with your pharmacist for guidance on the best disposal method or participate in a drug take-back program in your area, if available.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
To use this medication correctly, follow your doctor's instructions and read all the information provided. Take this medication with food to help your body absorb it properly. When it's time to take your dose, avoid consuming alcohol, hot drinks, or spicy foods, as they may interfere with the medication's effectiveness.
Storing and Disposing of Your Medication
Keep your medication at room temperature in a dry place, away from the bathroom. Store all medications in a safe location, out of the reach of children and pets. When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so by your pharmacist. Instead, check with your pharmacist for guidance on the best disposal method or participate in a drug take-back program in your area, if available.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
Lifestyle & Tips
- Take with food if stomach upset occurs.
- Maintain a balanced diet rich in B vitamins.
- Store at room temperature away from moisture and heat.
Available Forms & Alternatives
Available Strengths:
Dosing & Administration
Adult Dosing
Standard Dose:
500 mg orally once daily or as directed by a healthcare professional for supplementation. For pellagra, 50-100 mg orally 3-6 times daily.
Dose Range:
50 - 1000 mg
Condition-Specific Dosing:
pellagra:
50-100 mg orally 3-6 times daily
supplementation:
500 mg orally once daily
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
For pellagra: 10-50 mg orally 3-6 times daily, up to 300 mg/day. For supplementation, doses vary by age and weight, typically lower than adult doses.
Adolescent:
Similar to adult doses for supplementation, or as directed for specific deficiencies.
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment typically required for standard supplementation doses.
Moderate:
No specific adjustment typically required for standard supplementation doses.
Severe:
No specific adjustment typically required for standard supplementation doses. Caution with very high doses due to potential accumulation of metabolites.
Dialysis:
No specific adjustment typically required for standard supplementation doses. Niacinamide is water-soluble and dialyzable.
Hepatic Impairment:
Mild:
No specific adjustment typically required for standard supplementation doses.
Moderate:
No specific adjustment typically required for standard supplementation doses. Caution with very high doses.
Severe:
No specific adjustment typically required for standard supplementation doses. Caution with very high doses.
Pharmacology
Mechanism of Action
Niacinamide (nicotinamide) is an amide of nicotinic acid (niacin) and a precursor to the coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). NAD and NADP are essential for numerous metabolic processes, including redox reactions, ATP production, DNA repair, and cell signaling. Unlike nicotinic acid, niacinamide does not significantly affect lipid profiles (e.g., lower LDL, raise HDL) and typically does not cause the flushing associated with nicotinic acid.
Pharmacokinetics
Absorption:
Bioavailability:
High (nearly 100%)
Tmax:
Approximately 1-2 hours
FoodEffect:
Absorption may be slightly delayed but not significantly reduced by food.
Distribution:
Vd:
Widely distributed throughout body tissues.
ProteinBinding:
Low
CnssPenetration:
Yes
Elimination:
HalfLife:
Approximately 0.8 hours (for the parent compound, but metabolic products have longer half-lives)
Clearance:
Rapid renal clearance of parent compound and metabolites.
ExcretionRoute:
Renal (urine)
Unchanged:
Small percentage (less than 30%)
Pharmacodynamics
OnsetOfAction:
Not applicable (as a vitamin, effects are gradual and related to repletion of stores)
PeakEffect:
Not applicable
DurationOfAction:
Not applicable
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of high blood sugar, including:
+ Confusion
+ Feeling sleepy
+ Unusual thirst or hunger
+ Passing urine more often
+ Flushing
+ Fast breathing
+ Breath that smells like fruit
Signs of liver problems, such as:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Muscle pain or weakness
Chest pain or pressure
Dizziness or fainting
Shortness of breath
Excessive sweating
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other symptoms that bother you or persist, contact your doctor for guidance:
Flushing (taking aspirin 30 minutes before taking this medication may help; if you wake up at night with flushing, get up slowly if you feel dizzy or like passing out)
Itching
Diarrhea
Upset stomach
Vomiting
Cough
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects not mentioned here. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of high blood sugar, including:
+ Confusion
+ Feeling sleepy
+ Unusual thirst or hunger
+ Passing urine more often
+ Flushing
+ Fast breathing
+ Breath that smells like fruit
Signs of liver problems, such as:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Muscle pain or weakness
Chest pain or pressure
Dizziness or fainting
Shortness of breath
Excessive sweating
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other symptoms that bother you or persist, contact your doctor for guidance:
Flushing (taking aspirin 30 minutes before taking this medication may help; if you wake up at night with flushing, get up slowly if you feel dizzy or like passing out)
Itching
Diarrhea
Upset stomach
Vomiting
Cough
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects not mentioned here. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe stomach pain or persistent nausea/vomiting
- Unusual tiredness or weakness
- Yellowing of skin or eyes (jaundice)
- Dark urine
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, any of its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced as a result of the allergy.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This information will help your doctor and pharmacist assess potential interactions between this medication and other substances you are taking.
* Any existing health problems, as this medication may interact with certain conditions.
To ensure your safety, it is crucial to verify that it is safe to take this medication with all your current medications and health conditions. Never start, stop, or change the dose of any medication without first consulting your doctor.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, any of its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced as a result of the allergy.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This information will help your doctor and pharmacist assess potential interactions between this medication and other substances you are taking.
* Any existing health problems, as this medication may interact with certain conditions.
To ensure your safety, it is crucial to verify that it is safe to take this medication with all your current medications and health conditions. Never start, stop, or change the dose of any medication without first consulting your doctor.
Precautions & Cautions
It is essential to inform all of your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. If you have diabetes, it is crucial to closely monitor your blood sugar levels. Your doctor will instruct you on when to have blood work done, and it is vital to follow their guidance. Additionally, this medication may interfere with certain laboratory tests, so be sure to notify all of your healthcare providers and lab personnel that you are taking this drug.
To ensure safe and effective use, adhere to the diet and exercise plan recommended by your doctor. It is also recommended to limit or avoid alcohol consumption, as drinking more than 3 drinks per day may increase your risk of liver disease. Furthermore, alcohol may exacerbate flushing symptoms.
If you are pregnant, planning to become pregnant, or are breast-feeding, it is essential to discuss the potential benefits and risks of this medication with your doctor, as they will help you weigh the advantages and disadvantages for both you and your baby.
To ensure safe and effective use, adhere to the diet and exercise plan recommended by your doctor. It is also recommended to limit or avoid alcohol consumption, as drinking more than 3 drinks per day may increase your risk of liver disease. Furthermore, alcohol may exacerbate flushing symptoms.
If you are pregnant, planning to become pregnant, or are breast-feeding, it is essential to discuss the potential benefits and risks of this medication with your doctor, as they will help you weigh the advantages and disadvantages for both you and your baby.
Overdose Information
Overdose Symptoms:
- Severe gastrointestinal upset (nausea, vomiting, diarrhea)
- Liver damage (with very high, chronic doses)
- Headache
- Dizziness
What to Do:
Discontinue use. Seek medical attention. For severe symptoms, call Poison Control at 1-800-222-1222.
Drug Interactions
Moderate Interactions
- Isoniazid (may increase niacinamide requirement)
- Carbamazepine (may reduce niacinamide levels)
- Primidone (may reduce niacinamide levels)
- Phenobarbital (may reduce niacinamide levels)
- Phenytoin (may reduce niacinamide levels)
Monitoring
Baseline Monitoring
Clinical assessment for signs of deficiency (e.g., pellagra)
Rationale: To confirm need for supplementation or high-dose therapy.
Timing: Prior to initiation of high-dose therapy or for suspected deficiency.
Routine Monitoring
Clinical symptom improvement
Frequency: Ongoing
Target: Resolution of deficiency symptoms
Action Threshold: Lack of improvement may indicate inadequate dosing or alternative diagnosis.
Liver function tests (ALT, AST, bilirubin)
Frequency: Periodically, especially with very high doses (e.g., >3g/day) or in patients with pre-existing liver conditions.
Target: Within normal limits
Action Threshold: Significant elevation may warrant dose reduction or discontinuation.
Symptom Monitoring
- Gastrointestinal upset (nausea, vomiting, diarrhea)
- Skin rash or irritation (less common than with nicotinic acid)
- Headache
- Dizziness
Special Patient Groups
Pregnancy
Niacinamide is an essential vitamin. At recommended daily allowance (RDA) doses, it is considered safe and necessary during pregnancy (Category A). High doses exceeding the RDA should be used with caution and only if clearly needed, as safety at very high doses is not well-established (Category C).
Trimester-Specific Risks:
First Trimester:
Generally safe at RDA doses. High doses: caution.
Second Trimester:
Generally safe at RDA doses. High doses: caution.
Third Trimester:
Generally safe at RDA doses. High doses: caution.
Lactation
Niacinamide is naturally present in breast milk and is considered safe for use during lactation at recommended daily allowance (RDA) doses (L1). High doses should be used with caution.
Infant Risk:
Low risk at recommended doses.
Pediatric Use
Generally safe at appropriate pediatric doses for supplementation or deficiency. Dosing should be carefully adjusted by age and weight. High doses should be avoided unless specifically indicated and monitored by a physician.
Geriatric Use
Generally safe. No specific dose adjustments are typically required for standard supplementation doses. Elderly patients may have increased susceptibility to adverse effects at very high doses due to age-related changes in metabolism or renal function.
Clinical Information
Clinical Pearls
- Niacinamide is a form of Vitamin B3 that does NOT cause the 'niacin flush' commonly associated with nicotinic acid.
- It is primarily used for vitamin B3 deficiency (pellagra) and as a general nutritional supplement.
- Unlike nicotinic acid, niacinamide does not have significant lipid-lowering effects.
- High doses (e.g., >3g/day) may rarely cause liver enzyme elevations, though less frequently than nicotinic acid.
Alternative Therapies
- Nicotinic acid (Niacin) - Note: different pharmacological profile and side effects (flushing, lipid effects)
- Dietary sources of niacin (e.g., meat, poultry, fish, nuts, legumes, fortified cereals)
Cost & Coverage
Average Cost:
$5 - $30 per 100 tablets (500mg)
Generic Available:
Yes
Insurance Coverage:
Generally OTC; not typically covered by prescription drug plans unless prescribed for a specific medical condition and formulary allows.
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.