garlic

Complementary/Alternative Medicine: This monograph describes a natural or herbal product that is not subject to FDA guidelines for medicines. Patients and clinicians are advised to read package labels carefully to ensure safe and efficacious use.

REMS

PO: Cardiovascular disease prevention.
Colorectal and gastric cancer prevention.
Hyperlipidemia.
Hypertension.
Topical
Tinea cruris.
Tinea corporis.
Tinea pedis.

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Allergy to Allium (onion, leek, shallot);
Bleeding disorders;
Surgery (discontinue use ≥2 wk before procedure).

Use Cautiously in:

Diabetes;
GI infection or inflammation;
OB: Safety not established in pregnancy;
Lactation: Safety not established in breastfeeding;
Pedi: Safety and effectiveness not established in children.

Adv. Reactions/Side Effects ⬆ ⬇

GI: bad breath, diarrhea, flatulence, mouth, esophagus, and stomach irritation, nausea, vomiting

Derm: contact dermatitis, diaphoresis

Hemat: bleeding

Neuro: dizziness

Misc: hypersensitivity reactions (including asthma, rash, anaphylaxis [rare]), body odor

Interactions ⬆ ⬇

Natural-Drug Products:

Anticoagulants, antiplatelet agents, and thrombolytics may ↑ risk of bleeding.
May ↓ effectiveness of contraceptive drugs and cyclosporine.
May ↓ levels and effectiveness of nevirapine, isoniazid, and efavirenz.

Natural-Natural Products:

Angelica, anise, asafoetida, bogbean, boldo, capsicum, celery, chamomile, clove, danshen, dong quai, fenugreek, feverfew, ginger, ginkgo, Panax ginseng, horse chestnut, horseradish, licorice, meadowsweet, papain, passionflower, poplar, prickly ash, onion, quassia, red clover, turmeric, wild carrot, wild lettuce, and willow may ↑ risk of bleeding.

Availability ⬆ ⬇

Capsules: ^OTC
Tablets: ^OTC
Topical cream:
Topical gel: ^OTC
Fresh garlic: ^OTC

Route/Dosage ⬆ ⬇

PO (Adults ): 200–400 mg of standardized garlic powder extract with 1.3% allin 3 times daily. Fresh garlic: 1–7 cloves/day. One clove contains approximately 4 g of garlic.
(Adults ): Tinea infections: 0.4% cream, 0.6% gel, or 1% gel applied twice daily × 7 days.

US Brand Names ⬆ ⬇

Alli sativa bulbus, Allium sativum

Action ⬆ ⬇

May have HMG-CoA inhibitor properties in lowering cholesterol, but less effectively than statin drugs; vasodilatory and antiplatelet properties.

Therapeutic effects:

Decreased cholesterol levels.
Decreased platelet aggregation.

Classifications ⬆ ⬇

Therapeutic Classification: lipid-lowering agents

Pharmacokinetics ⬆ ⬇

Absorption: Garlic oil is well absorbed.

Distribution: Unknown.

Metabolism/Excretion: Kidney and lungs.

Half-Life: Unknown.

Time/Action Profile ⬆ ⬇

ROUTE	ONSET	PEAK	DURATION
PO	4–25 wk	unknown	unknown
Topical	30 min	unknown	unknown

Patient/Family Teaching ⬆ ⬇

Explain purpose and side effects of herb to patient.
Advise patient to consult with health care provider before using any herbal supplement, especially when taken concurrently with Rx or OTC medications or vitamins.
Advise patient about the need to follow a healthy diet (low in fat and high in vegetables and fruits) in conjunction with garlic. Other lipid-reducing strategies (exercise, smoking cessation) should also be used.
Advise patient there are other more effective agents for lipid ↓ available.
Caution patient about the potential risk for bleeding. Advise patient undergoing elective procedures to stop using garlic for ≥2 wk before procedures and to notify the surgeon if they are taking garlic in the event of emergent surgery.
Advise patient that allergies may occur and to discontinue use if symptoms develop.
Rep: Advise women of reproductive potential to notify health care provider if pregnancy is planned or suspected or breastfeeding before using this herb.

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Indications ⬇