DRUG-SUPPLEMENT INTERACTIONS IN LYME DISEASE
Interactions between prescription or over the counter drugs and nutritional supplements
are common and often not well known. In creating the Drug-Nutrient Workshop
(www.NutritionWorkshop.com), a professional database of interactions between drugs
and dietary supplements, nutrients, and food or food components, I found that over 400
drugs commonly used in the U.S. deplete specific nutrients and almost 500 drugs have
their efficacy or side effects influenced by various foods. I also identified about a
thousand adverse interactions between drugs and dietary supplements and several
hundred beneficial interactions, in which specific dietary supplements may enhance the
efficacy or decrease the side effects of specific drugs.
People with Lyme and related diseases are usually administered prolonged therapy with
antibiotics, often combined with Prilosec or other proton pump inhibitors (drugs that
greatly reduce stomach acid), sometimes in conjunction with Plaquenyl (an immune
modulator) or anti-parasitic drugs for treatment of babesiosis. Some potential interactions
(negative and positive) between these drugs and dietary supplements are described below.
Information on drug/food interactions is usually available from the pharmacist and
included in the patient-package insert. This should be checked for each individual drug
being taken, because the dosage form (sustained-release vs. regular, for example) may
influence the effect of food on drug absorption. Patients with chronic tick-borne
infections may also be taking antidepressants and pain relievers, each of which may have
its own interactions with nutritional supplements and nutritional status.
Drugs may interact with food or supplements through the following mechanisms:
(1) The food or supplements may interfere with drug absorption. This is especially
important for tetracycline or quinolone antibiotics. {Although quinolones like Levaquin
are not used for Lyme disease, they are the primary drugs for treatment of bartonellosis, a
common co-infection). Both groups of antibiotics form insoluble complexes with
minerals, especially calcium, magnesium or iron. This process, called chelation, inhibits
absorption of both the antibiotic and the mineral. Not only are most tetracyclines (with
the sole exception of doxycycline) and all quinolones better absorbed away from food
(especially mineral-rich foods like meat and dairy products), they must be taken several
hours apart from any nutritional supplements containing minerals. Two hours of
separation may not be enough. Several herbs, including fennel, dandelion, and
Sanguisorba, have a high enough mineral content that their consumption has been shown
Penicillins may have their oral absorption impaired by fiber or by food, although
this is more likely for penicillin V and ampicillin that for amoxacillin. Food causes the
drug to be retained in the stomach, where the presence of acid causes the drug to
decompose. Psyllium has been shown to bind oral penicillin, decreasing its absorption.
(2) The drug may increase the requirement for certain nutrients, because it causes
depletion of the nutrient from the body. The normal gastrointestinal bacterial flora
synthesize B vitamins, biotin and vitamin K, which are absorbed and utilized by humans.
Depletion of these bacteria by prolonged antibiotic therapy may produce vitamin deficits.
Bleeding caused by vitamin K deficiency has occurred as a result of intravenous therapy
with cephalosporin antibiotics1, a group that includes Rocephin and Claforan. High dose
penicillin therapy causes increased excretion of potassium by the kidneys2. When
combined with antibiotic-induced diarrhea or poor appetite, this effect may cause
potassium deficiency, with fatigue and muscle weakness as primary symptoms. Proton
pump inhibitors like Prilosec, used to enhance antibiotic absorption and cellular
penetration, decrease formation of stomach acid, permitting overgrowth of bacteria and/or
yeast in the stomach and upper gastrointestinal tract. Microbial overgrowth may be
associated with gastrointestinal symptoms like diarrhea and bloating3 and may cause
malabsorption of nutrients. Prolonged use of PPIs has been associated with decreased
absorption of vitamin B12, zinc, and carotene and may create a need for
(3) Drugs, supplements and food may interact by inhibition or stimulation of enzymes
involved in drug transport or metabolism.
The cytochrome P450 (CYP) system is extensively involved in drug metabolism and
may be strongly inhibited or stimulated by drugs, foods or dietary supplements. CYP
enzymes are most active in the liver, intestines, lungs and kidneys. Humans have over 20
different CYP enzymes, all of which contain iron and which all use oxygen to change the
structure and function of the drugs they metabolize. The most important CYP's for drug
metabolism are designated CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and
CYP3A4. This classification system is not based upon biological function but upon
similarity of amino acid sequences in the structure of the enzyme. CYP oxidation of drugs
may produce metabolites that are less active or more active than the parent compound.
The exact effect of inhibiting or stimulating any CYP enzyme will therefore depend upon
the specific clinical circumstances and cannot necessarily be predicted from experiments
Another important aspect of drug metabolism is transport into and out of cel s. Some
drugs are ejected from cells by a transport system referred to as P-glycoprotein (P-gp). In
the intestine, P-gp limits the absorption of a variety of unrelated drugs, many of which are
also metabolized by the intestinal form of CYP3A4. Inhibition of P-gp and/or CYP3A4
by grapefruit juice or other natural substances can increase absorption of drugs that are P-
gp or CYP3A4 substrates, raising their concentration in blood. This effect is only
important for drugs that are slowly absorbed in the intestine to begin with. Drugs that
pass through the intestinal lining rapidly are absorbed too quickly for inhibition of CYP
or P-gp enzymes in the intestine to affect drugs levels. St. John's wort is one of the few
products that stimulate intestinal P-gp and CYP3A4. Taking St. John’s wort can decrease
the plasma concentration of those same drugs and underlies many of the adverse drug
interactions reported for this herb.
Some important interaction of drugs used in treating tick-borne diseases and the CYP
CYP2C9 is increased by rifampin (an antibiotic sometimes used to treat
Bartonella) and inhibited by fluconazole (Diflucan, an anti-fungal).
CYP2C19 is increased by rifampin and artemisin (a derivative of the herb
Artemisia annua, a natural anti-malarial herb that may be used in the treatment of
Babesiosis). CYP2C19 is decreased by Prilosec and ketoconazole (Nizoral, an anti-
CYP3A4 is increased by St. John's wort and rifampin and inhibited by grapefruit
juice, Seville orange juice, the anti-fungal drugs ketoconazole (Nizoral) and itraconazole
(Sporanox), and the macrolide antibiotics azithromycin (Zithromax), clarithromycin
(Biaxin) and telithromycin (Ketek). The effect of grapefruit juice occurs only in the
intestines, not in the liver, so it can--at high levels of consumption--increase absorption of
some drugs without affecting their internal metabolism. Artemisinin is metabolized by
intestinal CYP3A4, and its absorption appears to be enhanced by grapefruit juice5. The
herb Echinacea, used for immune stimulation, inhibits intestinal CYP3A4 but stimulates
the liver's CYP3A4, so it may increase or decrease the levels of a co-administered drug,
depending upon the drug's rate of absorption and the extent to which it is metabolized by
Milk thistle, an herb used to support liver function, contains a group of
bioflavonoids called silymarin. Silymarin may inhibit intestinal P-gp and liver CYP3A4.
Surprisingly, concomitant administration of milk thistle significantly decreased the
absorption of metronidazole (a drug used to treat the spore form of Borrelia).6 This
interaction could not have been predicted from knowledge of the herb's effects on drug
metabolizing enzymes. Moreover, vitamin C (500 mg/day) and vitamin E (400 units/day)
decreased the effectiveness of metronidazole in treating H. pylori infection of the
stomach.7 The mechanism of this interaction is unknown but suggests that anti-oxidants
should not be used with metronidazole therapy.
Quercetin, a bioflavonoid used as an anti-oxidant and for relief of allergic
symptoms, competes with quinolone antibiotics for binding sites on bacteria. No
interaction between quercetin and antibiotics has yet been demonstrated outside a test
tube, but it would be prudent for people taking quinolone antibiotics to refrain from the
use of quercetin and perhaps other bioflavonoids.
Beneficial effects of dietary supplements for people taking antibiotics have been
described. The most consistent benefits have been demonstrated for probiotics (living
organisms) that can counter the gastrointestinal side effects of antibiotics. The best
studied are Saccharomyces boulardii (a yeast, dubbed "yeast against yeast" in France)8,
Lactobacillus rhamnosis GG9, Lactobacillus plantarum and Lactobacillus sporogenes10.
Proteases are enzymes that digest protein. When taken by mouth on an empty stomach
some of the preparation is absorbed intact and may be active in the body. Oral proteases
have been shown to relieve pain and inflammation in patients with arthritis11, may break
down circulating complexes of antigen and antibody (these have been described in so-
called "post-Lyme syndrome") and may breakdown blood clots that form as a result of
inflammation. Although research on proteases as adjuncts to antibiotic therapy is
minimal, a study done in animals found that bromelain (a protease-containing extract of
pineapple stem), increased penetration of tetracyclines into the tissues12.
1 Alitalo et al. Hypoprothrombinaemia and bleeding during administration of cefamandole and
cefoperazone. Ann Clin res 1985; 17: 116-9. Shimada et al. Bleeding secondary to vitamin K deficiency in
patients receiving parenteral cephem antibiotics. J Antimicob Chemother 1984; 14 (Suppl B): 325-330
2 Gill et al, Hypokalemic metabolic alkalosis induced by high-dose ampicillin sodium. Am J Hosp Pharm
3 Lewis et al, Altered bowel function and duodenal bacterial overgrowth in patients treated with
omeprazole. Alimentary Pharmacol Ther 1996; 10: 557-61.
4 Bradford & Taylor, Omeprazole and vitamin B12 deficiency. Ann Pharmacother 1999; 33: 641-43. Bellou
et al, Cobalamin deficiency with megaloblastic anemia in one patient under long-term omeprazole therapy. J
Intern Med 1996; 240: 161-4. Marcuard et al, Omeprazole therapy causes malabsorption of
cyanocobalamin. Ann Int med 1994; 120: 211-15. Tang et al, Gastric acidity influences the blood response
to a beta-carotene dose in humans. Am J Clin Nutr 1996; 64: 622-26.
5 van Agtmael et al, Grapefruit juice increases bioavailability the bioavailability of artemether. Eur J Clin
6 Rajnarayana et al, Study on the influence of silymarin pretreatment on metabolism and disposition of
metronidazole. Arzneimittelforschung 2004; 54: 109-13.
7 Chuang et al, Vitamin C and E supplements to lansoprazole-amoxacillin-metronidazole triple therapy may
reduce the eradication rate of metronidazole-sensitive Helicobacter pylori infection. Helicobacter 2002; 7:
8 Surawicz et al, Prevention of antibiotic-associated diarrhea by Saccharomyces boulardii: A prospective
9 Vanderhoof et al, Lactobacillus GG in the prevention of antibiotic-associated diarrhea in children. J
Pediatr 1999; 135: 564-48. Armuzzi et al, The effect of oral administration of Lactobacillus GG on
antibiotic-associated gastrointestinal side effects during helicobacter pylori eradication therapy. Aliment
10 LaRosa et al, Prevention of antibiotic-associated diarrhea with Lactobacillus sporogens and fructo-
oligosaccharides in children. A multicentre double-blind vs placebo study. Minerva Pediatr 2003; 55: 447-
11 Leipner et al, Therapy with proteolytic enzymes in rheumatic disorders.
12 Luerti & Vignali, Influence of bromelain on penetration of antibiotics in uterus, salpinx and ovary. Drugs
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