Meta Information
ID:fibrates
Name:Fibrates (gemfibrozil, fenofibrate)
Schema Version:2.4_uniform_evidence_2026_06_18
Created
2026-07-02T07:03:07Z
Model
phase-b-newfiles-claude-opus-4.8
Interactions
Target id:
/class/statins
Target name:
Statins (esp. with gemfibrozil)
Severity:
major
Interaction type:
adverse
Nature:
relative
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Fibrates plus statins substantially increase the risk of severe muscle injury (rhabdomyolysis), which can cause kidney failure.
Actionable advice:
Gemfibrozil + statin should not be combined (contraindicated); fenofibrate + statin should be used only with caution and CK/muscle monitoring.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Concomitant therapy with LOPID and an HMG-CoA reductase inhibitor is associated with an increased risk of skeletal muscle toxicity manifested as rhabdomyolysis, markedly elevated creatine kinase (CPK) levels, and myoglobinuria, leading in a high proportion of cases to acute renal failure and death.
Label source:
fda_label
Action type:
avoid
Target id:
/intervention/warfarin
Target name:
Warfarin
Severity:
major
Interaction type:
adverse
Nature:
relative
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Fibrates potentiate warfarin's anticoagulant effect, raising bleeding risk.
Actionable advice:
The warfarin dose should be reduced and INR monitored closely when starting a fibrate.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
The dosage of warfarin should be reduced to maintain the prothrombin time at the desired level to prevent bleeding complications.
Label source:
fda_label
Action type:
adjust_with_prescriber
Target id:
/intervention/repaglinide
Target name:
Repaglinide
Severity:
major
Interaction type:
contraindication
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Gemfibrozil dramatically raises repaglinide levels (CYP2C8/OATP inhibition), causing severe hypoglycemia.
Actionable advice:
Gemfibrozil should not be combined with repaglinide.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Co-administration of gemfibrozil and repaglinide increases the risk of severe hypoglycemia and is contraindicated.
Label source:
fda_label
Action type:
avoid
Target id:
/condition/gallstones
Target name:
Gallbladder / cholelithiasis
Severity:
moderate
Interaction type:
adverse
Nature:
relative
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Fibrates increase cholesterol excretion into bile, promoting gallstone formation.
Actionable advice:
Right-upper-abdominal pain is worth reporting; the fibrate should be stopped if gallstones are found.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Both clofibrate and gemfibrozil may increase cholesterol excretion into the bile, leading to cholelithiasis.
Label source:
fda_label
Action type:
monitor
Target id:
/intervention/colchicine
Target name:
Colchicine
Severity:
moderate
Interaction type:
adverse
Nature:
relative
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Fibrates can potentiate colchicine-associated muscle injury, especially with kidney impairment.
Actionable advice:
It is worth watching for muscle pain or weakness, and caution is warranted in kidney impairment.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Concomitant use of LOPID may potentiate the development of myopathy.
Label source:
fda_label
Action type:
monitor