CAM InteractionsE. DIETARYHigh Blood Pressure

Interaction between aliskiren and fruit juice

Aliskiren (Tekturna) is used to treat high blood pressure. It’s poorly absorbed from the intestines (about 2.5%).

Researchers at Helsinki University Central Hospital, in Finland, report that apple and orange juice further reduce the amount that gets absorbed from the intestines.

First, the details.

  • 12 healthy volunteers ingested 200 mL (about 7 oz) of orange juice, apple juice, or water 3 times daily for 5 days.
  • On day 3, they swallowed a single 150-mg dose of aliskiren.
  • Blood levels of aliskiren were measured for up to 72 hours, its excretion into urine for up to 12 hours; and blood renin activity was measured up to 24 hours.
  • Each volunteer took each treatment in random order — crossover.

And, the results.

  • Orange and apple juices reduced aliskiren peak blood levels 80% and 84%, respectively – significant changes.
  • The area under the plasma aliskiren concentration-time curve (AUC; a measure of total bioavailability) was reduced 62% and 63%, respectively — significant changes.
  • There was no significant effect on its elimination half-life or renal clearance (removal by the kidneys).
  • The decreases in aliskiren AUC by orange and apple juices were significantly greater than with aliskiren taken with water.
  • Renin activity was 87% and 67% higher at 24 hours after aliskiren during the orange-juice and apple-juice phases, respectively, than during the water phase — significant differences.
    • Renin is an enzyme released by the kidney to help control the body’s sodium-potassium balance, fluid volume, and blood pressure.

The bottom line?

The authors concluded, “Concomitant intake of aliskiren with orange or apple juice is best avoided.”

The mechanism behind this interaction is probably due to inhibition of OATP2B1 activity in the small intestine. OATP2B1 is a peptide in the intestines that works to transport material into the blood stream.

1/22/11 23:34 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.