CLOFIBRATE

CLOFIBRATE
(kloe-fy'brate)
Atromid-S, Claripex

, Novofibrate

Classifications: antilipemic; fibrate;
Therapeutic: cholesterol-lowering agent; antihyperlipidemic
Prototype: Fenofibrate
Pregnancy Category: C

Availability

500 mg capsules

Action

Structurally related to gemfibrozil. Mechanism of action appears to inhibit cholesterol biosynthesis prior to transfer of triglycerides from liver to serum. Interferes with binding of free fatty acids to albumin and increases fecal excretion of neutral sterols. It affects the mobilization of cholesterol from tissue.

Therapeutic Effect

Clofibrate reduces very low density lipoproteins (VLDL) to a greater extent than it reduces low density lipoproteins (LDL). It also lowers serum triglycerides more dramatically than cholesterol.

Uses

Adjunct for treatment of severe primary (type III) hyperlipidemia.

Unlabeled Uses

Management of diabetes insipidus.

Contraindications

Severely impaired renal function or significant hepatic dysfunction, primary biliary cirrhosis; hypothyroidism; peptic ulcer disease; pregnancy (category C), lactation. Safe use in children <14 y not established.

Cautious Use

History of jaundice or mild to moderate hepatic disease; gallstones; peptic ulcer; hypothyroidism; cardiovascular disease.

Route & Dosage

Hyperlipidemia
Adult: PO 2 g/d in 2–4 divided doses

Diabetes Insipidus
Adult: PO 1.5–2 g/d in 2–4 divided doses

Administration

Oral

If gastric distress is a problem, administer drug with meals.
Preserve in closed, light-resistant containers at 15°–30° C (59°–86° F) unless otherwise directed.

Adverse Effects (≥1%)

CV: Increase or decrease in angina, CHF, arrhythmias. GI: Nausea, vomiting, loose stools, diarrhea, flatulence, abdominal distress, gastritis, stomatitis, cholelithiasis. Hematologic: Neutropenia, leukopenia, anemia, eosinophilia, agranulocytosis, potentiation of anticoagulant effect. Metabolic: Elevated AST and ALT. Musculoskeletal: Flu-like symptoms. CNS: Drowsiness, dizziness, headache. Skin: Swelling and phlebitis at xanthoma sites, skin rash, allergy, urticaria, pruritus. Urogenital: Renal insufficiency, impotence, decreased libido.

Diagnostic Test Interference

Clofibrate therapy may lead to increased BSP retention, thymol turbidity; increased serum creatine phosphokinase (CPK); proteinuria, parodoxical increase in LDL or cholesterol levels (if there is a large decrease in VLDL level). Lower fasting blood glucose and serum insulin levels in patients with diabetes mellitus.

Interactions

Drug: oral anticoagulants increase hypoprothrombinemia and increase risk of bleeding; probenecid increases effects of clofibrate; sulfonylureas increase hypoglycemic effects.

Pharmacokinetics

Absorption: Readily absorbed from GI tract. Peak: 4–6 h. Distribution: Distributed to extracellular space; crosses placenta; distribution into breast milk unknown. Metabolism: Hydrolyzed in plasma to clofibric acid, which is further metabolized in liver. Elimination: In urine. Half-Life: 12–35 h.

Nursing Implications

Assessment & Drug Effects

Lab tests: Baseline and periodic lipid profile; periodic liver function tests, CBC, renal function tests, and determinations of plasma and urine steroid levels, serum electrolyte levels, and blood glucose.
Therapeutic response generally occurs during the first or second month of therapy. Rebound may occur in second or third month, followed by a further decrease, and may also occur with sudden withdrawal of drug.
Clofibrate therapy for increased serum cholesterol and triglycerides is generally withdrawn after 3 mo if the response is not adequate.

Patient & Family Education

Report flu-like symptoms (malaise, muscle soreness, aching, weakness) promptly to physician. Other reportable conditions include leukopenia, pulmonary edema, and renal insufficiency (see Appendix F) and gastric pain, nausea, and vomiting.
Women of childbearing years should be on birth control regimen. If pregnancy is desired, clofibrate therapy should be discontinued at least 2 mo before conception.
Do not self-dose with OTC drugs without the approval of physician.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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