Why Physicians Prescribe Zetia: Benefits, Dose, Side Effects

Genes Mentioned

• ABCG8

Ezetimibe, or “Zetia” for short is an important heart drug which helps people who hyper-absorb cholesterol (and plant sterol) from taking on more of these fats than their body can handle. In the IMPROVE-IT trials, Zetia lowered cardiovascular events and LDL-C in patients already on statin therapy. Zetia is standard of care for those who have sitosterolemia, a genetic condition marked by elevated levels of plant sterols in the blood. ¹ However, according to the Mayo Clinic, Zetia does have known side effects, one of which is dysphagia or trouble swallowing.

Zetia is well tolerated

In clinical trials, Zetia has been well tolerated, so this could be a good drug for you if you hyper-absorb cholesterol. In the IMPROVE-IT trial, 10mg of ezetimibe added to 40 mg of simvastatin reduced further heart attacks, but not many deaths, compared to simvastatin alone in patients sick with heart disease who already had their LDL-C lowered to less than 125 mg/dl. ² For the right class of patients, Zetia could make you healthier overall and may even extend your life. ³

Zetia 5 mg vs 10 mg dose

This study, which appeared in the American Journal of Managed Care, found that 5 mg doses of Zetia performed on par with 10 mg doses in lowering LDL-C. As such, some people may find that they tolerate Zetia at 5 mg and not at 10 mg. This is a conversation worth having with your doctor if you experience side effects at 10 mg doses.

Why I prescribe Zetia

Patinets with elevated levels of sitosterol (sometimes as high as 5.5 mg/dl) in the blood are good candidates for Zetia. Labs like Boston Heart Diagnostics measure sitosterol as a proxy marker for cholesterol absorption. Cholesterol is a type of fat only found in animals. Sitosterol is a “phytosterol” fat found in plants. The best heart labs measure for sitosterol for two reasons:

1. Sitosterol levels are thought to be a proxy for cholesterol absorption
2. An excess of sitsosterol (or any sterol) in the blood is linked to increased risk for heart disease

Under normal circumstances, sitosterol helps stop cholesterol absorption because it competes to get into the blood stream with cholesterol. ⁴ Whereas, the dietary cholesterol we absorb (which often isn’t much) makes its way into the blood stream and eventually back to the liver, under normal circumstances sitosterol and other phytosterols are only temporarily absorbed. When they get past the wall of the gut a process driven by two genes ABCG5 and ABCG8 kicks these sterols out of the gut wall where they are then excreted in stool. However, if you’re someone with loss of function in the ABCG5/8 genes, you may be hyper absorbing both plant sterols and cholesterol. When absorbed at high enough quantities, these phytosterols can be damaging to heart health. Of particular interest from a nutrition standpoint is this New England Journal of Medicine study which found that oxidized sterols bind preferentially to Lp(a), a particularly dangerous type of LDL particle, that apparently becomes further weaponized when phytosterols bind to it’s unique structure of proteins. ⁵ Zetia is not a statin, it does not stop the body from making its own cholesterol, it simply blocks absorption.

Zetia side effects

Again, according to the Mayo Clinic, these are the “more common” Zetia side effects:

• Fever
• headache
• muscle pain
• runny nose
• sore throat

However, when you scan down the list of “less common” side effects, you get a larger list:

• Back pain
• body aches or pain
• chest pain
• chills
• cold or flu-like symptoms
• congestion
• coughing
• diarrhea
• difficulty in moving
• dizziness
• dryness or soreness of throat
• hoarseness
• muscle pain or stiffness
• pain in joints
• pain or tenderness around eyes and cheekbones
• shortness of breath or troubled breathing
• stomach pain
• stuffy nose
• tender, swollen glands in neck
• tightness of chest or wheezing
• trouble in swallowing
• unusual tiredness or weakness
• voice changes

Key Takeaway

Zetia is a proven drug that has the potential to benefit people that tend to hyper-absorb cholesterol and plant sterol. However, as with any pharmaceutical drug, side effects are a real possibility. Lab tests that measure for plant sterols in the blood are hard to come by, but the Cholesterol Absorption Panel offered by Boston Heart Diagnostics does measure for all three absorption markers:

1. Sitosterol
2. Camposterol
3. Cholestanol

It is possible to call Boston Heart and ask for a physician in your area that administers the tests.