Last updated on RxList: 6/23/2017
Simcor Side Effects Center

Last reviewed on RxList 6/23/2017

Simcor (niacin extended-release/simvastatin) is a combination of a B vitamin (vitamin B3) and a cholesterol-lowering medication used to lower cholesterol and triglycerides (types of fat) in the blood. Lowering cholesterol and triglycerides can help prevent heart disease and coronary artery disease (also called atherosclerosis), conditions that can lead to heart attack, stroke, and vascular disease. Common side effects of Simcor include:

  • flushing (warmth, redness, itching, or tingling of the skin, especially of the face/neck),
  • sweating,
  • dizziness, or
  • chills within 2 to 4 hours after taking this medication.

Flushing may persist for a few hours. Side effects should improve or go away after several weeks as your body adjusts to Simcor. Other side effects of Simcor include:

Tell your doctor if you have serious side effects of Simcor including:

Simcor should be taken as a single daily dose of a 500/20 mg tablet at bedtime, with a low fat snack. Simcor may interact with amiodarone, cyclosporine, danazol, digoxin, fenofibrate, gemfibrozil, blood thinners, niacin, nicotinic acid, nicotinamide (or vitamin supplements that contain niacin), verapamil, antibiotics, antifungals, or HIV /AIDS medicine. Tell your doctor all medications and supplements you use. Simcor must not be used during pregnancy. Simvastatin may harm a fetus. Consult your doctor to discuss using at least 2 forms of birth control (such as condoms, birth control pills) while taking this medication. If you become pregnant or think you may be pregnant, tell your doctor. It is unknown if this medication passes into breast milk. Similar drugs pass into breast milk. Breastfeeding while using this drug is not recommended.

Our Simcor (niacin extended-release/simvastatin) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Simcor Consumer Information
SIDE EFFECTS: Flushing (warmth/redness/itching/tingling of the skin, especially of the face/neck), sweating, dizziness, or chills may occur within 2 to 4 hours after taking this medication. Flushing may persist for a few hours. These effects should improve or go away after several weeks as your body adjusts to the medication. Upset stomach, nausea, or diarrhea may also occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

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.

A very small number of people taking simvastatin may have mild memory problems or confusion. If these rare effects occur, talk to your doctor.

Rarely, statins may cause or worsen diabetes. Talk to your doctor about the benefits and risks.

Tell your doctor right away if any of these unlikely but serious side effects occur: severe dizziness, fainting, fast/pounding heartbeat, swelling ankles/feet/hands, shortness of breath, toe/joint pain, easy bruising/bleeding, black/tarry stools, vomit that looks like coffee grounds.

This drug may infrequently cause muscle problems (which can rarely lead to very serious conditions called rhabdomyolysis and autoimmune myopathy). Tell your doctor right away if you develop any of these symptoms during treatment and if these symptoms persist after your doctor stops this drug: muscle pain/tenderness/weakness (especially with fever or unusual tiredness), change in the amount of urine.

This medication may rarely cause liver problems. If you notice any of the following rare but serious side effects, tell your doctor right away: yellowing eyes/skin, dark urine, severe stomach/abdominal pain, persistent nausea/vomiting.

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.

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.

Read the entire patient information overview for Simcor (Simvastatin Niacin Extended Release)


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In a controlled clinical study, 14% of patients randomized to SIMCOR discontinued therapy due to an adverse event. Flushing episodes (i.e., warmth, redness, itching and/or tingling) were the most common treatment-emergent adverse reactions, occurring in up to 59% of patients treated with SIMCOR. Spontaneous reports with niacin extended-release and clinical studies of SIMCOR suggest that flushing may be accompanied by symptoms of dizziness or syncope, tachycardia, palpitations, shortness of breath, sweating, burning sensation/skin burning sensation, chills, and/or edema.

Clinical Studies Experience


Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice.

The safety data described below reflect exposure to SIMCOR in 403 patients in a controlled study for a period of 6 months.


Flushing (warmth, redness, itching and/or tingling) occurred in up to 59% of patients treated with SIMCOR. Flushing resulted in study discontinuation for 6.0% of patients.

More Common Adverse Reactions

In addition to flushing, adverse reactions occurring in ≥ 3% of patients (irrespective of investigator causality) treated with SIMCOR are shown in Table 4 below:

Table 4: Adverse Reactions Occurring in ≥ 3% of Patients in a Controlled Clinical Trial

Adverse Event SIMCOR overall * Simvas tatin overall **
Total Number of Patients N=403 N=238
Headache 18 (4.5%) 11 (4.6%)
Pruritus 13 (3.2%) 0 (0.0%)
Nausea 13 (3.2%) 10 (4.2%)
Back Pain 13 (3.2%) 5 (2.1%)
Diarrhea 12 (3.0%) 7 (2.9%)
* SIMCOR overall included all doses from 500/20 mg to 2000/40 mg
** Simvastatin overall included 20 mg, 40 mg, and 80 mg doses

Atherothrombosis Intervention In Metabolic Syndrome With Low HDL/High Triglycerides: Impact On Global Health Outcomes (AIM-HIGH)

In AIM-HIGH involving 3414 patients (mean age of 64 years, 15% women, 92% Caucasians, 34% with diabetes mellitus) with stable, previously diagnosed cardiovascular disease, all patients received simvastatin, 40 to 80 mg per day, plus ezetimibe 10 mg per day if needed, to maintain an LDL-C level of 40-80 mg/dL, and were randomized to receive NIASPAN 1500-2000 mg/day (n=1718) or matching placebo (IR Niacin, 100-150 mg, n=1696). The incidence of the adverse reactions of “blood glucose increased” (6.4% vs. 4.5%) and “diabetes mellitus” (3.6% vs. 2.2%) was significantly higher in the simvastatin plus NIASPAN group as compared to the simvastatin plus placebo group. There were 5 cases of rhabdomyolysis reported, 4 (0.2%) in the simvastatin plus NIASPAN group and one ( < 0.1%) in the simvastatin plus placebo group [see WARNINGS AND PRECAUTIONS].


In pre-marketing controlled clinical studies and their open extensions (2,423 patients with mean duration of follow-up of approximately 18 months) 1.4% of patients discontinued due to adverse reactions. The most commonly reported adverse reactions (incidence > 1%) in simvastatin controlled clinical trials were: headache (3.5%), abdominal pain (3.5%), constipation (2.3%), upper respiratory infection (2.1%), diarrhea (1.9%), and flatulence (1.9%).

Other Clinical Studies

In a clinical trial in which 12,064 patients with a history of myocardial infarction were treated with simvastatin (mean follow-up 6.7 years), the incidence of myopathy (defined as unexplained muscle weakness or pain with a serum creatine kinase [CK] > 10 times upper limit of normal [ULN]) in patients on 80 mg/day was approximately 0.9% compared with 0.02% for patients on 20 mg/day. The incidence of rhabdomyolysis (defined as myopathy with a CK > 40 times ULN) in patients on 80 mg/day was approximately 0.4% compared with 0% for patients on 20 mg/day. The incidence of myopathy, including rhabdomyolysis, was highest during the first year and then notably decreased during the subsequent years of treatment.

Niacin Extended-Release

In placebo-controlled clinical trials (n=245), flushing episodes were the most common treatmentemergent adverse events (up to 88% of patients) for niacin extended-release. Other adverse events occurring in 5% or greater of patients treated with niacin extended-release are headache (9%), diarrhea (7%), nausea (5%), rhinitis (5%), and dyspepsia (4%) at a maintenance dose of 1000mg daily.

Clinical Laboratory Abnormalities



Elevations in serum transaminases [see WARNINGS AND PRECAUTIONS], CK, fasting glucose, uric acid, alkaline phosphatase, LDH, amylase, γ-glutamyl transpeptidase, bilirubin, and reductions in phosphorus, and abnormal thyroid function tests.


Reductions in platelet counts and prolongation of PT [see WARNINGS AND PRECAUTIONS].

Postmarketing Experience

See also the full prescribing information for niacin extended release (Niaspan) and simvastatin products.

Because the below reactions are reported voluntarily from a population of uncertain size, it is generally not possible to reliably estimate their frequency or establish a causal relationship to drug exposure.


The following additional adverse reactions have been identified during postapproval use of simvastatin. Hypersensitivity reaction including one or more of the following features: 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, fatal and non-fatal hepatic failure, pruritus, cataracts, polymyositis, dermatomyositis, polymyalgia rheumatica, tendon rupture, peripheral neuropathy, 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.

There have been rare reports of immune-mediated necrotizing myopathy with statin use [see WARNINGS AND PRECAUTIONS].

There have been rare postmarketing reports of 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).


The following additional adverse reactions have been identified during post-approval use of NIASPAN. Hypersensitivity reaction including one or more of the following features: 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.

Read the entire FDA prescribing information for Simcor (Simvastatin Niacin Extended Release)

© Simcor Patient Information is supplied by Cerner Multum, Inc. and Simcor Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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