What is the mechanism of action of lomitapide?

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Multiple Choice

What is the mechanism of action of lomitapide?

Lomitapide works by inhibiting microsomal triglyceride transfer protein, or MTP. MTP’s job is to move triglycerides onto apolipoprotein B during the assembly of apoB-containing lipoproteins in the liver (VLDL) and intestine (chylomicrons). When MTP is blocked, fewer VLDL and chylomicrons are made and secreted, so there are fewer precursors to form LDL. That’s why LDL cholesterol drops. This action is distinct from other lipid drugs: statins inhibit HMG‑CoA reductase, fibrates activate PPAR‑alpha, and PCSK9 inhibitors prevent LDL receptor degradation. Lomitapide’s effect is specifically on MTP, reducing production of triglyceride-rich lipoproteins rather than changing cholesterol synthesis, receptor activity, or LDL clearance directly. In practice, this is particularly relevant for patients with homozygous familial hypercholesterolemia who may not reach goals with statins alone. Be mindful that lomitapide can cause hepatotoxicity and fatty liver, so liver function monitoring is important. It’s not used in pregnancy, and drug interactions can influence liver safety.

Lomitapide works by inhibiting microsomal triglyceride transfer protein, or MTP. MTP’s job is to move triglycerides onto apolipoprotein B during the assembly of apoB-containing lipoproteins in the liver (VLDL) and intestine (chylomicrons). When MTP is blocked, fewer VLDL and chylomicrons are made and secreted, so there are fewer precursors to form LDL. That’s why LDL cholesterol drops.

This action is distinct from other lipid drugs: statins inhibit HMG‑CoA reductase, fibrates activate PPAR‑alpha, and PCSK9 inhibitors prevent LDL receptor degradation. Lomitapide’s effect is specifically on MTP, reducing production of triglyceride-rich lipoproteins rather than changing cholesterol synthesis, receptor activity, or LDL clearance directly.

In practice, this is particularly relevant for patients with homozygous familial hypercholesterolemia who may not reach goals with statins alone. Be mindful that lomitapide can cause hepatotoxicity and fatty liver, so liver function monitoring is important. It’s not used in pregnancy, and drug interactions can influence liver safety.

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