Skip to Content

Niacin / simvastatin Side Effects

In Summary

More frequently reported side effects include: myopathy and nausea. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to niacin / simvastatin: oral tablet extended release

As well as its needed effects, niacin / simvastatin may cause unwanted side effects that require medical attention.

Major Side Effects

If any of the following side effects occur while taking niacin / simvastatin, check with your doctor immediately:

Incidence not known:
  • Abdominal or stomach pain, severe
  • black, tarry stools
  • chills
  • dark-colored urine
  • dizziness
  • fever
  • headache
  • light-colored stools
  • loss of appetite
  • muscle cramps or spasms
  • muscle pain or stiffness
  • muscular tenderness, wasting, or weakness
  • nausea or vomiting
  • rash
  • unpleasant breath odor
  • unusual tiredness or weakness
  • vomiting of blood
  • yellow eyes or skin

Minor Side Effects

Some niacin / simvastatin side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

More common:
  • Feeling of warmth
  • redness of the face, neck, arms, and occasionally, upper chest
Less common:
  • Back pain
  • diarrhea
  • itching skin

For Healthcare Professionals

Applies to niacin / simvastatin: oral tablet extended release


Niacin-simvastatin treatment was discontinued by 14% of patients in a controlled clinical trial due to an adverse event. Flushing episodes (including warmth, redness, itching, and/or tingling) were the most common side effects reported by patients using niacin-simvastatin.


Musculoskeletal side effects have included back pain (3.2%), myopathy, and rhabdomyolysis have been associated with simvastatin therapy. The risk of myopathy/rhabdomyolysis is dose related and is increased by concomitant use of simvastatin with potent Inhibitors of CYP450 3A4, as well as cyclosporine or danazol, particularly with higher doses of simvastatin.[Ref]


Liver function tests should be performed before treatment begins, every 12 weeks for the first 6 months, and periodically thereafter (e.g., at approximately 6-month intervals). Patients who develop increased transaminase levels should be monitored with a second liver function evaluation to confirm the finding and be followed thereafter with frequent liver function tests until the abnormality returns to normal. If a persistent increase in transaminase levels is seen (e.g., three times the upper limit of normal), or if transaminase elevations are associated with symptoms of nausea, fever, and/or malaise, withdrawal of niacin-simvastatin therapy is recommended.[Ref]

Severe hepatic toxicity has occurred in patients substituting sustained-release niacin for immediate-release niacin at equivalent doses. In addition, persistent elevations in hepatic transaminase can occur during niacin-simvastatin therapy.[Ref]


Dermatologic side effects including flushing (59%) and pruritus (3.2%) were reported in patients receiving the combination niacin-simvastatin product. Flushing episodes have also been associated with niacin monotherapy (in up to 88% of patients).[Ref]


Other side effects including headache (4.5%) and back pain (3.2%) have been associated with the combination niacin-simvastatin product.[Ref]


Gastrointestinal side effects associated with administration of the combination product have included nausea (3.2%) and diarrhea (3%). Diarrhea has also been associated with each of the individual components of the drug. Abdominal pain, constipation, and flatulence have also been associated with simvastatin monotherapy, while nausea and dyspepsia have been associated with niacin monotherapy.[Ref]


Respiratory side effects including upper respiratory infection and rhinitis have been associated with simvastatin and niacin, respectively.[Ref]


Metabolic side effects including increased serum glucose levels have been associated with niacin therapy. Therefore, glucose levels should be closely monitored in diabetic or potentially diabetic patients particularly during the first few months of use.[Ref]


Hypersensitivity side effects associated with simvastatin including one or more of the following features reported postmarketing have included: anaphylaxis, angioedema, lupus erythematous-like syndrome, vasculitis, purpura, thrombocytopenia, leucopenia, hemolytic anemia, positive ANA, ESR increase, eosinophilia, arthritis, photosensitivity, chills, toxic epidermal necrolysis, erythema multiforme, Stevens-Johnson syndrome, urticaria, fever, dyspnea, and arthralgia; pancreatitis, hepatitis, hepatic failure, pruritus, cataracts, polymyositis, dermatomyositis, polymyalgia rheumatica, global amnesia, tendon rupture, peripheral neuropathy, memory impairment, erectile dysfunction, depression, interstitial lung disease, alopecia, a variety of skin changes (e.g., nodules, discoloration, dryness of skin/mucous membranes, changes to hair/nails), muscle cramps, vomiting, malaise.

Hypersensitivity side effects associated with niacin including one or more of the following features reported postmarketing have included: anaphylaxis, dyspnea, angioedema, tongue edema, larynx edema, face edema, laryngismus; tachycardia, atrial fibrillation, other cardiac arrhythmias, palpitations, hypotension, postural hypotension, dizziness, syncope, flushing, burning sensation/skin burning sensation, paresthesia, urticaria, vesiculobullous rash, maculopapular rash, sweating, dry skin, skin discoloration, blurred vision, macular edema, myalgia, myopathy, peptic ulcers, eructation, flatulence, hepatitis, jaundice, peripheral edema, asthenia, nervousness, insomnia, migraine, gout, and decreased glucose tolerance.


Psychiatric side effects reported postmarketing have included cognitive impairment (e.g., memory loss, forgetfulness, amnesia, memory impairment, confusion) associated with statin use. These cognitive issues have been reported for all statins. The reports are generally nonserious, and reversible upon statin discontinuation, with variable times to symptom onset (1 day to years) and symptom resolution (median of 3 weeks).


1. "Product Information. Simcor (niacin-simvastatin)." Abbott Pharmaceutical, Abbott Park, IL.

It is possible that some side effects of niacin / simvastatin may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.