Niacin / Simvastatin

Pronunciation: (NYE-a-sin/SIM-va-STAT-in)
Class: Antihyperlipidemic combination

Trade Names

Simcor
- Tablets, ER niacin 500 mg/simvastatin 20 mg
- Tablets, ER niacin 750 mg/simvastatin 20 mg
- Tablets, ER niacin 500 mg/simvastatin 40 mg
- Tablets, ER niacin 1,000 mg/simvastatin 40 mg

Indications and Usage

Reduce total cholesterol, LDL cholesterol, apolipoprotein B, non-HDL cholesterol, or triglycerides, or increase HDL cholesterol in patients with primary hypercholesterolemia and mixed dyslipidemia (Fredrickson type IIa and IIb); reduce triglycerides in patients with hypertriglyceridemia (Fredrickson type IV hyperlipidemia).

Contraindications

Active liver disease; active peptic ulcer disease; arterial bleeding; women who are pregnant or may become pregnant; breast-feeding women; hypersensitivity to any component of the product.

Dosage and Administration

Adults

PO Patients not currently receiving niacin ER and patients currently on niacin products other than ER should start with a single niacin 500 mg/simvastatin 20 mg tablet daily at bedtime. Patients already taking simvastatin 20 to 40 mg who need additional management of their lipid levels may be started on niacin 500 mg/simvastatin 40 mg at bedtime. The dosage of niacin ER should not be increased by more than 500 mg daily every 4 wk. The recommended maintenance dosage is 1,000/20 mg to 2,000/40 mg once daily depending on tolerability and lipid levels. Doses of more than 2,000/40 mg daily are not recommended.

General Advice

Take once daily at bedtime with a low-fat snack.
If therapy is discontinued for more than 7 days, retitration as tolerated is recommended.
Take tablets whole and do not break, crush, or chew before swallowing.
Avoid administration on an empty stomach.
Avoid concomitant alcoholic, hot drinks, or spicy foods.
Simcor should only be substituted for equivalent doses of niacin ER. Do not substitute with other modified-release (eg, sustained-release or timed-release) niacin or immediate-release niacin.

Storage/Stability

Store between 68° and 77°F.

Drug Interactions

Alcohol

Avoid concurrent use. Use with caution in patients who consume substantial quantities of alcohol.

Amiodarone, azole antifungal agents (eg, itraconazole, ketoconazole), cyclosporine, danazol, delavirdine, efavirenz, fibrates (eg, gemfibrozil), grapefruit juice (more than 1 quart/day), macrolide antibiotics (eg, erythromycin, telithromycin), nefazodone, protease inhibitors (eg, ritonavir), verapamil

May increase the risk of myopathy and rhabdomyolysis. Avoid concurrent use.

Antihypertensive therapy (eg, ganglionic blocking agents, vasoactive agents)

Niacin may potentiate the effects of these agents, resulting in postural hypotension.

Aspirin

Metabolic Cl of niacin may be decreased.

Bile acid sequestrants (eg, cholestyramine, colestipol)

Because niacin may bind to these agents, separate the administration times by as much as possible (at least 4 to 6 h).

Bosentan, carbamazepine, efavirenz, rifamycins (eg, rifampin)

Simvastatin metabolism may be increased, resulting in a decrease in simvastatin plasma levels and efficacy.

Coumarin anticoagulants (eg, warfarin)

Bleeding and increased PT and INR may occur. Monitor anticoagulant function when starting, stopping, or changing the Simcor dose.

Digoxin

Digoxin plasma concentrations may be elevated.

Propranolol

Simvastatin plasma levels may be decreased.

St. John's wort

May decrease simvastatin levels; avoid coadministration.

Laboratory Test Interactions

Niacin may produce false elevations in some fluorometric determinations of plasma or urinary catecholamines; niacin may give false-positive reactions with cupric sulfate solution (Benedict reagent) in urine glucose tests.

Adverse Reactions

The following adverse reactions were reported with Simcor administration. Adverse reactions occurring with administration of either niacin or simvastatin are listed in their respective monographs.

CNS

Headache (5%).

Dermatologic

Flushing; (59%); pruritus (3%).

GI

Diarrhea, nausea (3%).

Lab Tests

Abnormal thyroid function tests; elevated alkaline phosphatase, amylase, bilirubin, fasting blood glucose, glutamyl transpeptidase, LDH, serum transaminases, and uric acid; decreased phosphorus and platelet counts; prolonged PT.

Musculoskeletal

Back pain (3%).

Precautions

Monitor

Closely monitor patients with renal impairment. Monitor lipid panel at regular intervals. Monitor LFTs before treatment begins, every 12 wk for the first 6 mo, then periodically thereafter (every 6 mo).

Pregnancy

Category X . May cause fetal harm.

Lactation

Niacin

Excreted in breast milk.

Simvastatin

Undetermined.

Children

Safety and efficacy not established.

Renal Function

Use with caution. Do not start treatment in patients with severe renal impairment unless patient already tolerates treatment with simvastatin 10 mg or higher.

Hepatic Function

Contraindicated in active liver disease or unexplained transaminase elevations. Use with caution in patients with a history of liver disease.

Diabetes

May increase fasting blood glucose.

Flushing

Frequency or severity of niacin-induced flushing may be reduced by taking aspirin or other NSAIDs approximately 30 min prior to Simcor . Flushing, pruritus, and GI distress may be reduced by gradually increasing the niacin dose and avoiding administration on an empty stomach.

Liver dysfunction

Severe hepatic toxicity, including fulminant hepatic necrosis, has occurred in patients substituting sustained-release niacin for immediate-release niacin in equivalent doses.

Myopathy/Rhabdomyolysis

Have been reported when simvastatin is used in combination with lipid-lowering doses of niacin.

Overdosage

Symptoms

Insufficient data. Patients have recovered from a simvastatin overdose of 3.6 g without sequelae.

Patient Information

Advise patient to take this medication at bedtime, after a low-fat snack.
Advise patient that this medication should be swallowed whole and not to break, crush, or chew tablets.
Advise patients that if dosing is interrupted for any length of time, they should contact their health care provider before restarting therapy.
Instruct patients to immediately notify their health care provider if they experience any unexplained muscle pain, tenderness, or weakness.
Advise patients that if bothersome flushing occurs, taking aspirin or another NSAID (eg, ibuprofen) 30 min before taking niacin/simvastatin may minimize flushing.
Caution patients that if flushing awakens them during the night, to rise slowly to reduce the chances of dizziness or fainting.
Advise patients to avoid ingestion of alcohol, hot beverages, and spicy foods around the time they take niacin/simvastatin to minimize flushing.
Instruct diabetic patients to monitor their blood glucose more frequently when this medication is started or the dose is changed, and to notify their health care provider of changes in blood glucose readings.
Advise women of childbearing age to use an effective method of birth control.
Advise women who are breast-feeding not to use this medicine.