Complementary Alternative Cardiovascular Medicine

54 Alternative Cardiovascular Medicine
Two interesting recent publications described the safety and efficacy of
a proprietary St. John’s wort preparation, Ze 117, that effectively treats
depression (39), but has low hyperforin content, which is the phloroglucinol
derivative formerly regarded as the chief active antidepressant constituent
of St. John’s wort. Clinical pharmacokinetic studies have shown
that Ze 117 does not interact appreciably with either CYP3A4 or Pgp (40),
whereas hyperforin induces hepatic CYP3A4 via the pregnane X receptor
(41). This raises the prospect of developing an efficacious hyperforin-free
St. John’s wort preparation; such products would not increase the clearance
of those therapeutically important drugs seriously affected by the
usual hyperforin-charged St. John’s wort preparations.
Coenzyme Q10
Reports of CoQ10 interacting with warfarin, producing a decreased
response to the anticoagulant, have been discredited in a recent randomized,
double-blind, placebo-controlled crossover trial (42). The effects
of CoQ10 and ginkgo on warfarin dosage were assessed; no statistically
significant influence on the response to warfarin was detected for either
substance. The authors of the study suggest that the interaction observed
in the case reports resulted from either health problems of the subjects
involved or impurities in the products used.
FOOD PLANTS/NUTRIENTS
Many food plants can also interact with warfarin. For example, its
anticoagulant effect can be diminished by vitamin K in greens (43) and
broccoli (44), as well as by large amounts of avocado (45). One case
report documents a significantly decreased INR in a 44-yr-old man who
consumed 1.13–3.75 L of green tea (Camellia sinensis) daily for approx
1 wk, while being maintained on warfarin (46).
The juice of Seville (sour) orange (Citrus aurantium), which is popular
as a promoter of weight loss and used to knock out intestinal CYP 450
3A4 isoenzyme in bioavailability studies, can cause cardiac disturbances
in individuals with severe hypertension and tachyarrythmias. The sympathomimetic
amines m-synephrine (phenylephrine) and octapine have
been indicted as the agents responsible for adverse effects, but further
studies are needed to confirm such speculation (47). The hemodynamics
of normotensive subjects were not significantly affected.
Red wine decreases the bioavailability of cyclosporine by as much as
50%, both area under the concentration-vs-time curve (AUC) and peak
concentration being significantly reduced (48).