Does byakkokaninjinto interact with antibiotics?

 Researchers from Aichi Medical University School of Medicine, in Japan studied the potential for the Kampo medicine, byakkokaninjinto (aka BN), to alter the metabolism of 2 antibiotics (ciprofloxacin (Cipro) and tetracycline).

The Kampo preparation, BN, is used to treat dry mouth, hot flashes, and perspiration.

In addition to calcium, BN contains the following herbals.

  • Gypsum fibrosum
  • Anemarrhenae rhizoma
  • Glycyrrhizae radix
  • Ginseng radix
  • Oryzae semen

Now, the details.

  • 20 people received the following treatments at 1-week intervals.
    • 1 dose of tetracycline (250 mg)
    • 1 dose of ciprofloxacin (200 mg)
    • 1 dose of tetracycline (250 mg) + 1 pack (3 grams) of BN
    • 1 dose of ciprofloxacin (200 mg) + 1 pack (3 grams) of BN
  • Concentrations of the antibiotics in blood and urine were measured.

And, the results.

  • Taking BN with either antibiotic resulted in significantly decreased peak blood levels (Cmax) and area under the plasma concentration-time curves (AUC) of the antibiotics.
    • The pharmacokinetic term, “area under the curve” is a measure of the extent of drug absorption.
  • BN didn’t affect the time to reach the maximum blood level (Tmax) for either antibiotic.
  • Overall, there was a small (15%) decrease in bioavailability of ciprofloxacin compared to tetracycline (30%).
  • BN significantly decreased the urinary recovery of tetracycline, but not ciprofloxacin.
  • And there was no change in the ability of the kidney to remove the antibioics from the body.

The bottom line?
All these changes indicate BN reduces the bioavailability of ciprofloxacin and tetracycline. This doesn’t occur because of changes in the kidney. Rather, BN reduces absorption of the antibiotics from the intestines due to binding with calcium.

The authors recommend not to take BN at the same time as the antibiotics (especially tetracycline).

6/7/09 19:43 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 www.Vicus.com, a complementary and alternative medicine website.