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Pronunciation |
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(jem
FI broe
zil) |

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U.S. Brand
Names |
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Lopid® |

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Generic
Available |
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No |

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Canadian Brand
Names |
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Apo®-Gemfibrozil;
Nu-Gemfibrozil |

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Synonyms |
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Cl-719 |

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Pharmacological Index |
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Antilipemic Agent (Fibric Acid) |

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Use |
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Treatment of hypertriglyceridemia in types IV and V hyperlipidemia for
patients who are at greater risk for pancreatitis and who have not responded to
dietary intervention |

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Pregnancy Risk
Factor |
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C |

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Contraindications |
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Hypersensitivity to gemfibrozil or any component; significant hepatic or
renal dysfunction; primary biliary cirrhosis; pre-existing gallbladder
disease |

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Warnings/Precautions |
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Possible increased risk of malignancy and cholelithiasis. No evidence of
cardiovascular mortality benefit. Anemia and leukopenia have been reported.
Elevations in serum transaminases can be seen. Discontinue if lipid response not
seen. Be careful in patient selection; this is not a first- or second-line
choice. Other agents may be more suitable. Adjustments in warfarin therapy may
be required with concurrent use. Use caution when combining gemfibrozil with
HMG-CoA reductase inhibitors (may lead to myopathy, rhabdomyolysis). Renal
function deterioration has been seen when used in patients with a serum
creatinine >2.0 mg/dL. Safety and efficacy in pediatric patients have not
been established. |

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Adverse
Reactions |
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>10% Gastrointestinal: dyspepsia (19.6%)
1% to 10%:
Central nervous system: Fatigue (3.8%), vertigo (1.5%), headache (1.2%)
Dermatologic: Eczema (1.95), rash (1.7%)
Gastrointestinal: Abdominal pain (9.8%), diarrhea (7.2%), nausea/vomiting
(2.5%), constipation (1.4%)
<1% or case reports with probable causation (Limited to important or
life-threatening symptoms): Hypoesthesia, paresthesia, taste perversion,
cataracts, intracranial hemorrhage, peripheral vascular disease, cholestatic
jaundice, dizziness, somnolence, peripheral neuritis, decreased libido,
depression, headache, blurred vision, impotence, myopathy, myasthenia, myalgia,
arthralgia, synovitis, rhabdomyolysis, increased creatinine phosphokinase,
increased bilirubin, increased transaminases, increased alkaline phosphatase,
anemia, leukopenia, bone marrow hypoplasia, eosinophilia, angioedema, laryngeal
edema, urticaria, exfoliative dermatitis, rash, dermatitis, pruritus,
vasculitis, Raynaud's phenomenon, hypokalemia, nephrotoxicity,
dermatomyositis/polymyositis
Reports where causal relationship has not been established: Weight loss,
extrasystoles, pancreatitis, hepatoma, colitis, confusion, seizures, syncope,
retinal edema, decreased fertility (male), renal dysfunction, positive ANA,
drug-induced lupus-like syndrome, thrombocytopenia, anaphylaxis, vasculitis,
alopecia, photosensitivity. |

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Overdosage/Toxicology |
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Symptoms of overdose include abdominal pain, diarrhea, nausea, vomiting
Following GI decontamination, treatment is supportive |

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Drug
Interactions |
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CYP3A3/4 enzyme substrate
Chlorpropamide: May increase risk of hypoglycemia.
Cyclosporine's blood levels may be reduced; monitor cyclosporine levels and
renal function.
Furosemide: Increased blood levels of both in hypoalbuminemia.
Glyburide (and possibly other sulfonylureas): The hypoglycemic effects may be
increased.
HMG-CoA reductase inhibitors (atorvastatin, cerivastatin, fluvastatin,
lovastatin, pravastatin, simvastatin) may increase the risk of myopathy and
rhabdomyolysis. The manufacturer warns against the concurrent use of lovastatin.
However, combination therapy with statins has been used in some patients with
resistant hyperlipidemias (with great caution).
Rifampin: Decreased gemfibrozil blood levels.
Warfarin: Hypoprothrombinemic response increased; monitor INRs closely when
gemfibrozil is initiated or discontinued. |

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Mechanism of
Action |
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The exact mechanism of action of gemfibrozil is unknown, however, several
theories exist regarding the VLDL effect; it can inhibit lipolysis and decrease
subsequent hepatic fatty acid uptake as well as inhibit hepatic secretion of
VLDL; together these actions decrease serum VLDL levels; increases HDL
cholesterol; the mechanism behind HDL elevation is currently
unknown |

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Pharmacodynamics/Kinetics |
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Onset of effect: May require several days
Absorption: Well absorbed
Protein binding: 99%
Metabolism: In the liver by oxidation to two inactive metabolites
Half-life: 1.4 hours
Time to peak serum concentration: Within 1-2 hours
Elimination: A portion of the drug undergoes enterohepatic recycling;
excreted in urine, primarily as unchanged drug (70%) |

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Usual Dosage |
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Adults: Oral: 1200 mg/day in 2 divided doses, 30 minutes before breakfast and
dinner |

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Dietary
Considerations |
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Before initiation of therapy, patients should be placed on a standard
cholesterol-lowering diet for 3-6 months and the diet should be continued during
drug therapy. |

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Monitoring
Parameters |
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Serum cholesterol, LFTs |

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Cardiovascular
Considerations |
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Selection of lipid-lowering therapy should be based on the patient's lipid
profile, concomitant disease states, and the cost of therapy. Gemfibrozil
increases HDL, decreases total cholesterol and triglycerides. A recent study
(HIT), showed that gemfibrozil therapy resulted in a significant reduction in
the risk of major cardiovascular events in patients with low HDL cholesterol.
These findings suggest that the rate of coronary events is reduced by raising
HDL cholesterol levels and lowering triglyceride levels. The treatment of low
HDL in the general population, is not established. |

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Mental Health: Effects
on Mental Status |
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May cause sedation; may rarely cause depression |

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Mental Health:
Effects on Psychiatric
Treatment |
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None reported |

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Dental Health: Local
Anesthetic/Vasoconstrictor
Precautions |
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No information available to require special precautions |

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Dental Health:
Effects on Dental Treatment |
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No effects or complications reported |

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Patient
Information |
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You must return to provider for assessment of drug effectiveness. Should be
taken 30 minutes before meals. Take with milk or meals if GI upset occurs. You
may experience loss of appetite and flatulence (frequent small meals may help),
muscle aches (mild, temporary pain relievers may be required), dizziness,
faintness, or blurred vision (use caution when driving or engaging in tasks that
require alertness until response to drug is known). Report severe stomach pain,
nausea, vomiting, chills, sore throat, headache, and any vision changes.
Pregnancy/breast-feeding precautions: Inform prescriber if you are or intend
to be pregnant. Do not breast-feed. |

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Nursing
Implications |
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Monitor serum cholesterol; abnormal elevation of AST, ALT, LDH, bilirubin and
alkaline phosphatase have occurred; if no appreciable triglyceride or
cholesterol, lowering effect occurs after 3 months, the drug should be
discontinued |

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Dosage Forms |
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Capsule: 300 mg
Tablet, film coated: 600 mg |

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References |
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Ahmad S, "Gemfibrozil Interaction With Warfarin Sodium," Chest, 1990,
98(4):1041-2.
Todd PA and Ward A,
"Gemfibrozil: A Review of Its Pharmacodynamic and Pharmacokinetic Properties and Therapeutic Use in Dyslipidaemia,"
Drugs, 1988, 36(3):314-39. |

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