Hypericin: New Dosage Information

The last issue of AIDS Treatment News (#74, February 24, 1989) included a major report on human experience with hypericin, an experimental antiviral readily available in certain extracts of the St. John's wort plant. The following updates are based on information we received after the article was published.


Dose Calculation Error

In our February 24 article, we calculated equivalent doses for the Hyperforat tincture from Germany, and St. John's wort tablets (Yerba Prima Botanicals) which are more available and convenient, and less expensive (page 4 of that article). We calculated that the 120 drops of Hyperforat (the dose with the most human experience so far) would be equivalent to three and a half of the tablets, each of which contains 250 mg of 0.14 percent hypericin. (Both products are standardized for hypericin content, so different lots should have the same strength.)

Since the article was published, a chemist told us that our calculations were probably incorrect. According to his information, the correct dose would be about two tablets, not three and a half, to be equivalent to 120 drops of Hyperforat tincture.

Our error was that when we converted drops to milliliters, in order to calculate the amount of hypericin in 120 drops of tincture, we used a ratio of 20 drops per milliliter, a standard conversion factor in medicine. However, the chemist explained that the 20 drops applies to pure water, but that a mixture of water and alcohol, as found in herbal tinctures, has different surface characteristics resulting in smaller drops. He estimates that there would be 40 to 45 drops per milliliter.

We could not obtain the Hyperforat product by press time for a direct test, but two other hypericin tinctures we tested both fell within this range. If Hyperforat does also, then the 120- drop daily dose of that product would be equivalent to somewhat less than two of the tablets, instead of three and one half-based on the specified hypericin content of the two products.

Animal Studies Suggest Less Frequent Use

We spoke again with the team at New York University which did the laboratory and animal studies published last July in the Proceedings of the National Academy of Sciences, USA. In further animal studies, they have consistently found that giving hyperi- cin less often than once a day has worked better as an antiretroviral than giving it every day.

For example, a single dose of ten micrograms was less effective than a single dose of 100 micrograms. But ten daily doses, of ten micrograms each, worked less well than even the single 10 microgram dose.

The animals were given larger doses relative to body weight than people have been using. The scientists emphasized that this information should in no way be interpreted as recommending any specific dose at this time.

The researchers are now preparing their animal results for publication, but the paper will not be published for several months at least. They pointed out that there is no guarantee that findings in animal studies will apply to humans--or to HIV, which in laboratory tests seems to be more sensitive to hypericin than the animal retroviruses they had been using-- and that only clinical trials can determine the best dose and schedule for human use.

Editorial Comment: At this time there is no human experience with a less frequent schedule. Everyone we have talked to who has used St. John's wort extracts has used them every day as recommended for antidepressant use in Europe.

In the reports so far, clinical benefits have usually been found within three to four weeks of starting daily use of standardized hypericin preparations (See AIDS Treatment News issue #74). Therefore within a month it might be clear whether or not the treatment is working for a patient. If not, the treatment might be discontinued; if it is working, then if the person decides to change to a less frequent dosage schedule, the benefits already seen can serve as a baseline for comparing whether or not the new schedule seems to be better.

More Good News--But Caution Needed

Before going to press we asked Dr. David Payne, four of whose patients have been using hypericin for three to four months, if there was any new information in the two weeks since we published our last issue. All four of them have continued to improve clinically. T-helper count increases have remained disappointingly slow--not surprising since these patients started with counts less than 10.

In our last issue we reported that one of the four patients had gone from P24 antigen positive to negative while using hypericin. Results are now back on two of the others. One of them has also gone from positive to negative. The other has remained positive, but the antigen level improved, from over 400 to 117.

The fourth patient was P24 negative from the beginning.

Despite the continuing good results, the information so far available about hypericin is very preliminary. No one knows the best dose or dosage regimen, no one knows which patients may be most likely to benefit, and no one knows if the herbal extracts will prove effective or even safe in long-term use. It is important that some people try hypericin, so that we will find out soon whether or not it is useful; that is already happening. But it would be risky for this treatment possibility to come into widespread use before more is known.

There is no great rush to start using hypericin. The largest buyer's club, the PWA Health Group in New York, received many calls about St. John's wort extracts, but sold only a few dozen bottles in the week after our article came out. The Healing Alternatives Foundation in San Francisco has also had only moderate sales. Fortunately, people are being cautious. Or perhaps a treatment which costs about 25 cents a day is unlikely to be taken very seriously.

Because there have been many disappointments before, including some treatments which looked good at first but turned out to be harmful, we emphasize again that no one knows how hypericin will turn out, and therefore caution is important.

Note: As we went to press we heard from a physician that one patient using St. John's wort tablets and no other treatment had a liver function test result four times normal--which might or might not have been caused by the herbal extract. This case reinforces the suggestion, published in our last issue, to have one's physician monitor a blood-chemistry panel when using hypericin. The research team at New York University found small, temporary changes in liver function and other blood- chemistry values in some rhesus monkeys given the chemical.

We do not know what tablets were used, or what dose, or how long.

Dr. Payne checked the records of his four patients who had used hypericin for three months or more, and found no such problem. Two had elevated liver enzymes before starting hypericin; both have improved while they used it. A third had a slight elevation while on hypericin; however, he had done well enough to resume AZT, which could have been the cause. The fourth was normal throughout.


**********