Fenofibrate
Fenofibrate, sold under the brand name Tricor among others, is a medication of the fibrate class used to treat abnormal blood lipid levels. It is less preferred to statin medications as it does not appear to reduce the risk of heart disease or death. Its use is recommended together with dietary changes. It is taken by mouth.
Common side effects include liver problems, breathing problems, abdominal pain, muscle problems, and nausea. Serious side effects may include toxic epidermal necrolysis, rhabdomyolysis, gallstones, blood clots, and pancreatitis. Use in pregnancy and breastfeeding is not recommended. It works by a number of mechanisms.
It was patented in 1969, and came into medical use in 1975. It is available as a generic medication. In 2017, it was the 70th most commonly prescribed medication in the United States with more than eleven million prescriptions.
Medical uses
Fenofibrate is mainly used for primary hypercholesterolemia or mixed dyslipidemia. Fenofibrate appears to decrease the risk of cardiovascular disease and possibly diabetic retinopathy in those with diabetes mellitus, and firstly indicated for the reduction in the progression of diabetic retinopathy in patients with type 2 diabetes and existing diabetic retinopathy in Australia. It also appears to be helpful in decreasing amputations of the lower legs in this same group of people. Fenofibrate also has an off-label use as an added therapy of high blood uric acid levels in people who have gout.It is used in addition to diet to reduce elevated low-density lipoprotein cholesterol, total cholesterol, triglycerides, and apolipoprotein B, and to increase high-density lipoprotein cholesterol in adults with primary hypercholesterolemia or mixed dyslipidemia.
- Severe hypertriglyceridemia type IV or V
Statins remain the first line for treatment of blood cholesterol. AHA guidelines from 2013 did not find evidence for routine use of additional medications.
Additionally, in 2016, the FDA filed "Withdrawal of Approval of Indications Related to the Coadministration With Statins in Applications for Niacin Extended-Release Tablets and Fenofibric Acid Delayed Release Capsules" noting "the Agency has concluded that the totality of the scientific evidence no longer supports the conclusion that a drug-induced reduction in triglyceride levels and/or increase in HDL cholesterol levels in statin-treated patients results in a reduction in the risk of cardiovascular events. Consistent with this conclusion, FDA has determined that the benefits of niacin ER tablets and fenofibric acid DR capsules for coadministration with statins no longer outweigh the risks, and the approvals for this indication should be withdrawn."
Contraindications
Fenofibrate is contraindicated in:- Patients with severe renal impairment, including those receiving dialysis
- Patients with active liver disease, including those with primary biliary cirrhosis and unexplained persistent liver function test abnormalities
- Patients with preexisting gallbladder disease
- Nursing mothers
- Patients with known hypersensitivity to fenofibrate or fenofibric acid
Adverse effects
- Headache
- Back pain
- Nasopharyngitis
- Nausea
- Myalgia
- Joint pain or arthralgia
- Diarrhea
- Upper respiratory tract infection
- Calculi
Precautions
Musculoskeletal
- Myopathy and rhabdomyolysis; increased risk when coadminstered with a statin, particularly in the elderly and patients with diabetes, kidney failure, hypothyroidism
- Can increase serum transaminases; liver tests should be monitored periodically
- Can increase serum creatinine levels; renal function should be monitored periodically in patients with chronic kidney disease
- Can increase cholesterol excretion into the bile, leading to risk of cholelithiasis; if suspected, gallbladder studies are indicated. See "Interaction" section under Bile acid sequestrant
- Exercise caution in concomitant treatment with oral Coumadin anticoagulants. Adjust the dosage of Coumadin to maintain the prothrombin time/INR at desired level to prevent bleeding complications.
Overdose
Interactions
These drug interactions with fenofibrate are considered major and may need therapy modifications:- Bile acid sequestrants : If taken together, bile acid resins may bind to fenofibrate, resulting in a decrease in fenofibrate absorption. To maximize absorption, patients need to separate administration by at least 1 h before or 4 h to 6 h after taking the bile acid sequestrant.
- Immunosuppressants : An increased risk of renal dysfunction exists with concomitant use of immunosuppressants and fenofibrate. Approach with caution when coadministering additional medications that decrease renal function.
- Vitamin K antagonists : As previously mentioned, fenofibrate interacts with coumadin anticoagulants to increase the risk of bleeding. Dosage adjustment of vitamin K antagonist may be necessary.
- Statins: Combination of statins and fenofibrate may increase the risk of rhabdomyolysis or myopathy.
Mechanism of action
Fenofibrate is a fibric acid derivative, a prodrug comprising fenofibric acid linked to an isopropyl ester. It lowers lipid levels by activating peroxisome proliferator-activated receptor alpha. PPARα activates lipoprotein lipase and reduces apoprotein CIII, which increases lipolysis and elimination of triglyceride-rich particles from plasma.
PPARα also increases apoproteins AI and AII, reduces VLDL- and LDL-containing apoprotein B, and increases HDL-containing apoprotein AI and AII.
Formulations
Fenofibrate is available in several formulations and is sold under several brand names, including Tricor by AbbVie, Lipofen by Kowa Pharmaceuticals America Inc, Lofibra by Teva, Lipanthyl, Lipidil, Lipantil micro and Supralip by Abbott Laboratories, Fenocor-67 by Ordain Health Care, Fibractiv 105/35 by Cogentrix Pharma, Fenogal by SMB Laboratories, Antara by Oscient Pharmaceuticals, Tricheck by Zydus, Atorva TG by Zydus Medica, Golip by GolgiUSA and Stanlip by Ranbaxy. Different formulations may differ in terms of pharmacokinetic properties, particularly bioavailability; some must be taken with meals, whereas others may be taken without regard to food.The active form of fenofibrate, fenofibric acid, is also available in the United States, sold as Trilipix. Fenofibric acid may be taken without regard to the timing of meals.
Controversy
In the United States, Tricor was reformulated in 2005. This reformulation is controversial, as it is seen as an attempt to stifle competition from generic equivalents of the drug, and is the subject of antitrust litigation by generic drug manufacturer Teva. Also available in the United States, Lofibra is available in 54 and 160 mg tablets, as well as 67, 134, and 200;mg micronized capsules. Generic equivalents of Lofibra capsules are currently available in all three strengths in the United States. In Europe, it is available in either coated tablet or capsule; the strength range includes 67, 145, 160 and 200 mg. The differences among strengths are a result of altered bioavailability due to particle size. For example, 200 mg can be replaced by 160 mg micronized fenofibrate. The 145 mg strength is a new strength that appeared in 2005-2006 which also replaces 200 or 160 mg as the fenofibrate is nanonised.History
Fenofibrate was first synthesized in 1974, as a derivative of clofibrate, and was launched on the French market shortly thereafter. It was initially known as procetofen, and was later renamed fenofibrate' to comply with World Health Organization International Nonproprietary Name guidelines.Fenofibrate was developed by Groupe Fournier SA of France, which was acquired in 2005 by Solvay Pharmaceuticals, a business unit of the Belgian corporation Solvay S.A.. In 2009, Solvay was, in turn, acquired by Abbott Laboratories.