G
(SHT). No known contraindications during pregnancy and lactation (SKY). Some people are
very allergic to garlic. Contraindicated in hyperthyroidism (TRA). Commission E reports rare
GI disturbances, allergic reactions, change of odor of skin and breath. Sulphides may irritate
the GI tract or cause dermatosis (CAN). Allergic reactions of contact dermatosis and severe
asthmatic attacks (from inhalation of garlic powder). Topical application of garlic or garlic oil
may cause local irritating effects. Nausea, vomiting, and diarrhea may occur following ingestion
of fresh garlic bulbs, extracts, or oil (AEH1). Fresh garlic is reportedly dangerous to children
(AHP). Use sparingly with children under 2 years; may irritate mouth or stomach if used too
liberally (WAM). Then there is Miller and Murray’s extremely cautious, but not critical review
(MAM). Though possibly “useful for mild hypertension ... routine use is not recommended.”
After informing us that no drug-drug interactions have been reported for garlic, they provide a
long list of potential drug-drug interactions. Hasty readers, especially MDs, will take this as
proven drug-garlic interactions, “Avoid concomitant use ... with NSAIDS, anticoagulants, and
drugs that inhibit liver metabolism (e.g., cimetidine (Tagamet), ciproflaxin (Cipro), clarithro-
mycin, diltiazem (Cardizem), enoxacin, erythromycin, fluoxetine (Prozac), fluvoxamine, itra-
conazole, ketoconazole, nefazodone, paroxetine (Paxil), ritonavir) may at least additively and
perhaps synergistically interact with garlic.” (MAM) Watch also with drugs extensively metab-
olized by the liver (alprazolam, amitriptyline, astemizole, carbamazepine, cisapride, clozapine,
corticosteroids, cyclosporine, desipramine, diazepan (Valium), imipramine, phenytoin (Dilan-
tin), propranolol, terfenadine (Seldane), theophylline, triazolam, warfarin (Coumadin), and
drugs that may be affected by liver inhibition (e.g., propranolol, diazepam) (MAM). MAM
tabulates allergic contact dermatosis, burning GI sensations, diaphoresis, diarrhea, light-head-
edness, menorrhagia, metrorrhagia, nausea, spinal epidural hematoma, and vomiting as side
effects of garlic (MAM). MAM even tries to attribute a case of spinal hematoma to garlic (in
an 87-year-old man ingesting 2 g daily “to prevent heart disease”). Perhaps they are too eager
to accentuate the negative, attributing the problem “to garlic’s ability to inhibit normal platelet
function.” Still accentuating the negative MAM talk about rats given massive doses (50 mg/day
garlic powder) developing degenerative changes in 45 days and severe testicular lesions after
70 days (MAM). The credibility of their uncritical data is questionable; for example, on page
144, they talk about 0.75 mg garlic EO divided in three doses a day causing anorexia, nausea,
severe vomiting, diarrhea, marked weight loss, metrorrhagia, and menorrhagia, yet on page 145
they casually discuss a dosage more than three orders of magnitude higher for 20 days, lowering
platelet aggregation from 30.37% to 21.21% (MAM). At 3 × 300 mg/day coated garlic powder
tablet, GI discomfort was the most frequent side effect; also bloating, dizziness, headache,
hypotensive circulatory reactions, outbreaks of sweating; daily doses of 900–1200 mg were
associated with garlic odor.
Extracts (Garlic) — Extracts >30 ml/kg orl ipr scu in mus rat. Active hypoglycemic compounds
may have insulin-sparing activity, the thiol groups competing for insulin with the inactivating
compounds (PNC). Ajoene antiaggregant, antilipoxygenase, antiprostaglandin (CAN; PNC);
synergizes antiaggregant activity of dipyramidole, forskolin, indomethacin, and prostacyclin.
Garlic (or allicin) antiseptic to Aeromonas, Aspergillus, Bacillus, Candida albicans, Citrobacter,
Cryptococcus, Epidermophyton, Escherichia coli, Herpes, Influenza, Klebsiela, Microsporum,
Proteus, Providencia, Rhodotorula, Salmonella paratyphi, Salmonella typhi, Shigella dysenter-
ica, Staphylococcus aureus, Torulopsis, Trichomonas spp, Trichophyton, Trichosporum, and
Vibrio cholerae (CAN; PNC). LD50 = 60 mg/kg ivn mouse (SHT), 120 mg/kg scu mouse (M11;
SHT). Might be a good way to cut back on your grocery bill (except for garlic), if you believe
this quote “Rats fed up to 2000 mg/kg garlic extract for 6 months showed no weight loss but
did show a slightly reduced food intake relative to controls.” There were no changes in renal
function, hematologic parameters, or selected serologic parameters, and there was no evidence