Submodule
Statins and HMG-CoA Reductase
Statins reduce mevalonate-pathway cholesterol synthesis, increase hepatic LDL receptor expression, and remain foundational because their LDL lowering and outcomes evidence are supported across broad risk states.
- HMG-CoA reductase inhibition
- LDL receptor upregulation
- Intensity and disposition
- Muscle, liver, interaction, and reproductive safety
Reduce mevalonate pathway flux
Activate sterol-responsive transcription
Increase receptor availability at the surface
Lower LDL-C through hepatic uptake
Convert synthesis inhibition into clearance
Statins competitively inhibit HMG-CoA reductase, reducing mevalonate-pathway flux and hepatocyte cholesterol. Sterol-responsive signaling increases LDL receptor expression, and the liver clears more circulating apoB particles. The plasma effect therefore depends on synthesis and a functioning clearance pathway.
Use intensity, not milligram mythology
High, moderate, and low intensity describe expected percentage LDL-C reduction categories for named drug-dose combinations. Milligrams are not interchangeable across products. Baseline LDL-C, adherence, secondary causes, inherited receptor disease, and analytical variation influence the observed response.
Follow the exact disposition pathway
Statins differ in CYP metabolism, hepatic uptake transporters, efflux transporters, renal contribution, active metabolites, lipophilicity, and half-life. A strong inhibitor may matter greatly for one statin and little for another. Product-specific checking is safer than a single class interaction rule.
Evaluate symptoms without abandoning prevention
Muscle complaints require timing, distribution, severity, competing causes, interactions, thyroid and kidney context, and CK when clinically indicated. Severe weakness, dark urine, systemic illness, or marked CK elevation requires urgent evaluation. When safe, dose adjustment, a different statin, intermittent strategies, or nonstatin support can preserve LDL lowering.
Use current liver and reproductive guidance
Obtain clinically appropriate baseline liver information and investigate persistent or symptomatic abnormalities rather than treating every mild fluctuation as hepatic failure. Pregnancy and lactation decisions use current product labeling, not retired letter categories. Most pregnant patients stop statin therapy, while exceptional very-high-risk cases require specialist judgment.
Quick check
Submodule
Cholesterol Absorption and Bile-Acid Pathways
Ezetimibe blocks NPC1L1-mediated cholesterol uptake, while bile acid sequestrants bind bile acids in the gut. Both lower hepatic cholesterol but create different interaction and tolerability problems.
- NPC1L1 inhibition
- Bile acid sequestration
- Medication spacing
- Triglyceride and gastrointestinal constraints
Reduce intestinal cholesterol uptake
Interrupt enterohepatic recycling
Increase bile acid synthesis or receptor demand
Prevent absorption interactions and worsening hypertriglyceridemia
Block cholesterol transport with ezetimibe
Ezetimibe inhibits NPC1L1 at the intestinal brush border, reducing absorption of dietary and biliary cholesterol. Lower hepatic cholesterol supports LDL receptor-mediated clearance. It is an oral option for additional LDL lowering and is mechanistically different from a resin.
Interrupt bile acid recycling
Cholestyramine, colestipol, and colesevelam bind bile acids in the intestinal lumen. Fecal loss increases hepatic conversion of cholesterol to bile acids and promotes LDL receptor demand. The drugs remain in the gut, so formulation burden and local effects dominate tolerability.
Protect absorption of other therapy
Resins can bind medicines and nutrients. Separation instructions depend on the exact resin and affected medication. Ezetimibe itself should be separated from a bile acid sequestrant according to its label. A written schedule is more useful than telling a patient to take medicines at different times.
Do not worsen the phenotype
Bile acid sequestrants can increase triglycerides and may be unsuitable in marked hypertriglyceridemia. Constipation, obstruction risk, swallowing, powder preparation, and fat-soluble nutrient issues also matter. Ezetimibe review includes cyclosporine exposure, combination liver safety, muscle symptoms, and fibrate-related gallbladder concerns.
Quick check
Submodule
PCSK9 Biology and Injectable Therapies
PCSK9 promotes LDL receptor degradation. Monoclonal antibodies neutralize circulating protein, while inclisiran reduces hepatic PCSK9 production through RNA interference.
- Receptor recycling
- Alirocumab and evolocumab
- Inclisiran siRNA
- Devices, schedules, access, and adherence
The complex enters the hepatocyte
The receptor returns to the surface
Fewer receptors remain available
Block circulating PCSK9 or reduce hepatic production
Preserve the LDL receptor
An LDL receptor normally releases its cargo after internalization and can return to the hepatocyte surface. PCSK9 binding redirects the receptor toward lysosomal degradation. Less PCSK9 activity leaves more receptors available for repeated LDL particle clearance.
Neutralize circulating PCSK9 protein
Alirocumab and evolocumab are monoclonal antibodies that bind circulating PCSK9. They are not interchangeable device by device or schedule by schedule. Product selection includes the indication, presentation, dose, storage, self-administration ability, and access pathway.
Reduce hepatic production with inclisiran
Inclisiran is a GalNAc-conjugated small interfering RNA delivered to hepatocytes. The RNA-induced silencing complex degrades PCSK9 messenger RNA. Current labeling uses healthcare-professional administration initially, again at 3 months, and then every 6 months.
Build a reliable exposure system
Potency does not compensate for a missed shipment, untrained device user, incorrect storage, or absent clinic appointment. Record where the drug is obtained, who administers it, the next due date, missed-dose plan, injection reactions, LDL response, and financial continuity.
Quick check
Submodule
ATP-Citrate Lyase and Other LDL Pathways
Bempedoic acid blocks ATP-citrate lyase upstream of HMG-CoA reductase after liver-selective activation, adding an oral LDL pathway with a distinct safety and interaction profile.
- ATP-citrate lyase inhibition
- Liver-selective activation
- Hyperuricemia and tendon injury
- Combination and statin interaction planning
Feeds acetyl-CoA production
Reduced acetyl-CoA limits cholesterol synthesis
Activation is concentrated in hepatocytes
Mechanism does not eliminate product-specific toxicity
Move upstream of HMG-CoA reductase
ATP-citrate lyase generates cytosolic acetyl-CoA that feeds cholesterol and fatty-acid synthesis. Bempedoic acid inhibition lowers hepatic cholesterol synthesis upstream of the statin target and supports increased LDL receptor-mediated clearance.
Understand tissue-selective activation
Bempedoic acid is converted to its active form mainly in the liver by an activating enzyme not present in skeletal muscle. This differentiates tissue exposure from statins, but it does not guarantee that every patient will be free of musculoskeletal complaints.
Monitor the distinctive hazards
Current labeling includes hyperuricemia and tendon injury risk. Ask about gout and tendon disease, review renal context and coexposures that affect tendons, and counsel patients to report acute tendon pain, swelling, or impaired movement promptly.
Check the complete regimen
Bempedoic acid can affect exposure to selected statins, so the exact combination and dose matter. Reassess LDL-C response, adherence, uric acid when clinically indicated, gout, tendon symptoms, and any new muscle or liver findings rather than monitoring LDL alone.
Quick check
Submodule
Triglyceride-Lowering Pharmacology
Fibrates, prescription omega-3 products, and apoC-III-directed therapy act through different pathways and solve different clinical problems. Product, phenotype, and immediate treatment goal must align.
- PPAR-alpha activation
- Gemfibrozil versus fenofibrate
- Prescription omega-3 products
- Olezarsen for familial chylomicronemia
Increase fatty-acid oxidation and LPL activity
Distinct product, dose, and outcomes evidence
Increase clearance in adult FCS
Match monitoring to the exact therapy
Activate PPAR-alpha with fibrates
Fenofibrate and gemfibrozil alter transcription related to fatty-acid oxidation, lipoprotein lipase activity, apoC-III, and triglyceride-rich particle metabolism. Renal function, liver disease, gallbladder disease, creatinine, anticoagulation, and muscle toxicity shape use.
Treat gemfibrozil as a distinct interaction problem
Gemfibrozil has a particularly concerning interaction with statins, with labeling that warns about severe myopathy, rhabdomyolysis, and acute renal failure. Fenofibrate also requires caution with statins but cannot be used as evidence that a gemfibrozil combination is safe.
Name the prescription omega-3 product
Icosapent ethyl contains prescription EPA and has product-specific triglyceride and cardiovascular evidence. Mixed EPA and DHA products have different compositions and effects, and over-the-counter supplements are not substitutes for studied prescription products. Review atrial fibrillation and bleeding risks where relevant.
Silence apoC-III in adult FCS
Olezarsen is a GalNAc-conjugated antisense oligonucleotide that degrades apoC-III messenger RNA, improving clearance of triglyceride-rich particles. Its current labeled role is adjunctive treatment with diet for adults with familial chylomicronemia syndrome, not routine mild hypertriglyceridemia.
Quick check
Submodule
Rare Dyslipidemia Therapies
Evinacumab, lomitapide, and olezarsen address severe inherited phenotypes through ANGPTL3 inhibition, apoB assembly blockade, or apoC-III RNA targeting and require specialist systems of care.
- ANGPTL3 inhibition
- MTP inhibition
- LDL receptor-independent lowering
- Specialty monitoring and nutrition
Lower LDL-C in HoFH without requiring normal LDLR activity
Reduce apoB lipoprotein assembly
Treat adult familial chylomicronemia
Coordinate indication, organ safety, nutrition, and adherence
Inhibit ANGPTL3 with evinacumab
Evinacumab is an intravenous monoclonal antibody used with other therapy for homozygous familial hypercholesterolemia. ANGPTL3 inhibition can lower LDL-C even when normal LDL receptor function is severely impaired, which distinguishes it from therapies that depend primarily on receptor upregulation.
Block apoB assembly with lomitapide
Microsomal triglyceride transfer protein transfers lipid during apoB lipoprotein assembly. Lomitapide inhibition reduces VLDL and chylomicron production but can increase hepatic fat and cause gastrointestinal toxicity. Its HoFH program requires liver surveillance, interaction control, low-fat intake, nutrient planning, and pregnancy prevention.
Match mechanism to inherited disease
HoFH can require receptor-independent LDL lowering, while FCS requires attention to triglyceride clearance and pancreatitis. A mechanism that is transformative for one rare phenotype may be inappropriate for another. Genotype, phenotype, residual pathway function, and prior response all matter.
Treat the system, not only the number
Rare therapies rely on infusion or specialty distribution, prior authorization, nutritional support, family assessment, reproductive planning, and expert follow-up. A laboratory response is one part of care, alongside organ safety, pancreatitis or ASCVD outcomes, tolerability, and sustained access.
Quick check
Module test
Check the connections.
Each attempt draws 10 questions from the complete 100 question bank.
Each attempt draws a fresh set and rearranges the answer choices.
References
Current clinical foundation.
Lecture material was synthesized with the following contemporary guidance. Verify local policy and current guidance before applying clinical information.
- ACC and AHA. 2026 Dyslipidemia Guideline
- FDA. Rosuvastatin Prescribing Information
- FDA. Repatha Prescribing Information
- FDA. Leqvio Prescribing Information
- FDA. Nexletol Prescribing Information
- DailyMed. Ezetimibe Prescribing Information
- DailyMed. Fenofibrate Prescribing Information
- DailyMed. Gemfibrozil Prescribing Information
- FDA. Tryngolza Prescribing Information
- FDA. Evkeeza Prescribing Information