statin interactions
8 interactions related to statin interactions
pravastatin + grapefruit
Unlike simvastatin, lovastatin, and atorvastatin, pravastatin is not significantly broken down by the gut enzyme CYP3A4 that grapefruit blocks. Controlled pharmacokinetic studies show grapefruit juice does not meaningfully change pravastatin levels, so grapefruit in normal dietary amounts is fine with this statin.
rosuvastatin + berberine
Rosuvastatin is carried into liver cells by the OATP1B1 transporter. In a laboratory study using human liver-cell cultures, berberine increased OATP1B1 activity and pushed more rosuvastatin into the cells. This is an early, test-tube signal only: there is no human or animal data showing it changes blood levels, cholesterol response, or side-effect risk in real life.
lovastatin + grapefruit
Grapefruit blocks the intestinal enzyme CYP3A4 that normally limits how much lovastatin reaches your bloodstream. With that enzyme suppressed, lovastatin levels can rise sharply, raising the risk of muscle injury and, rarely, rhabdomyolysis. Spacing the timing does not help because the effect lasts for days.
atorvastatin + vitamin d
Vitamin D's active metabolite (calcitriol) can mildly induce CYP3A4, the liver enzyme that breaks down atorvastatin, which can lower atorvastatin blood levels. Despite this, the cholesterol-lowering effect appears largely preserved, so the combination is generally fine. Strip precise dose targets and review high-dose vitamin D regimens with your doctor or pharmacist.
simvastatin + berberine
Simvastatin is activated and cleared by the CYP3A4 enzyme. A human study found that repeated berberine inhibits CYP3A4, which could raise simvastatin levels and increase the risk of muscle-related side effects. Some animal data suggest berberine can also induce CYP3A4 over time, so the net effect on statin exposure is hard to predict. There are no published human case reports of myopathy from this specific combination, so the concern is mechanistic and moderate.
atorvastatin + st. john's wort
St. John's wort induces CYP3A4, the enzyme that metabolizes atorvastatin, lowering statin exposure and weakening cholesterol-lowering efficacy over time.
simvastatin + st. john's wort
St. John's wort induces the CYP3A4 enzyme and the P-glycoprotein transporter that simvastatin depends on, sharply increasing the drug's first-pass breakdown. In a controlled crossover study of healthy volunteers, two weeks of St. John's wort substantially lowered the amount of active simvastatin reaching the bloodstream, weakening its cholesterol-lowering effect.
atorvastatin + berberine
In human trials, adding berberine to a statin did not raise muscle or liver side effects, and the two are sometimes studied together for cholesterol. The earlier claim that berberine meaningfully raises atorvastatin levels and risk is not supported by human evidence.