Na-500 Oral

Flushing/warmth in the face and neck, headache, itching, burning, sweating, chills, or tingling may occur within 20 minutes to 4 hours of taking this medication. Flushing may persist for a few hours. These effects should improve or go away as your body adjusts to the medication. Stomach upset, heartburn, nausea, vomiting, and diarrhea may also occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position. This is very important if you are also taking medication to lower your blood pressure.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor right away if you have any serious side effects, including: severe dizziness/fainting, fast/irregular heartbeat, severe headache (migraine), unusual joint pain, swelling of legs/arms, vision problems, severe stomach/abdominal pain, black stools, easy bruising/bleeding, unexplained muscle pain/tenderness/weakness, persistent nausea/vomiting, change in the amount of urine, dark urine, vomit that looks like coffee grounds, yellowing eyes/skin.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking niacin, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
If you have any of the following health problems, consult your doctor or pharmacist before using this medication: very low blood pressure, alcohol use, history of bleeding problems (such as low platelets), diabetes, gallbladder disease, glaucoma, gout, heart disease (such as recent heart attack, unstable angina), kidney disease, liver disease/increase in liver enzymes, untreated mineral imbalance (low phosphate levels), history of stomach/intestinal ulcers, underactive thyroid (hypothyroidism).
This drug may make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
This medication may infrequently make your blood sugar level rise, which can cause or worsen diabetes. Tell your doctor immediately if you develop symptoms of high blood sugar, such as increased thirst and urination. If you already have diabetes, be sure to check your blood sugars regularly. Your doctor may need to adjust your diabetes medication, exercise program, or diet.
During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.
This medication passes into breast milk. Consult your doctor before breast-feeding.

See also How to Use section.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor\'s approval.
Some products that may interact with this drug include: \"blood thinners\" (such as warfarin, heparins).
Check all prescription and nonprescription medicine labels carefully since vitamins/dietary supplements may also contain niacin or niacinamide (nicotinamide). These may increase your risk of side effects if taken together. Ask your doctor or pharmacist for more details.
This medication may interfere with certain laboratory tests (including urine or blood catecholamines, copper-based urine glucose tests), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.

If overdose is suspected, contact a poison control center or emergency room immediately. US residents can call the US National Poison Hotline at 1-800-222-1222. Canada residents can call a provincial poison control center.

NOTES:
If you are taking this for high cholesterol, in addition to eating a proper diet (such as a low-cholesterol/low-fat diet), other lifestyle changes that may help this medication work better include exercising, losing weight if overweight, and stopping smoking. Consult your doctor for more details.
Remember that it is best to get your vitamins and minerals from food whenever possible. Maintain a well-balanced diet, and follow any dietary guidelines as directed by your doctor. B vitamins (including niacin) are found in meat, fish, poultry, enriched/whole grain bread products, and fortified cereals. Eat more of these foods to increase the amount of niacin in your diet if you have a niacin deficiency.
There are many niacin products available. Some can be purchased without a prescription. Consult your doctor or pharmacist about the best product for you.
Laboratory tests (such as blood lipids, blood sugar, liver function tests, uric acid levels) may be performed (especially if prescribed for cholesterol/triglyceride control) to monitor your progress or check for side effects. Consult your doctor for more details.
Do not share this medication with others.

MISSED DOSE:
If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

STORAGE:
Store at room temperature away from moisture and light. Do not store in the bathroom. Refer to storage information printed on the package. If you have any questions about storage, ask your pharmacist. Keep all medications away from children and pets.
Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised June 2012. Copyright(c) 2012 First Databank, Inc.