soy

General

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.

Pronunciation:
soi


Trade Name(s)

  • glycine max
  • soy protein
  • isoflavone

Ther. Class.

antioxidants

caloric sources

Common Uses

  • Menopausal symptoms.
  • Prevention of breast, lung, endometrial, thyroid and prostate cancers.
  • Hyperlipidemia.

Action

Soy is the most significant dietary source of isoflavones. Pharmacologic effects of soy include lowering of homocysteine levels, inhibition of platelet aggregation, lowering of BP, inhibition of cholesterol absorption in the small bowel and lowering of LDL cholesterol. Soy isoflavones also have antioxidant, antiproliferative and estrogenic effects.

Therapeutic Effect(s):

  • Decreased cholesterol.
  • Decreased hot flashes in menopausal women.

Pharmacokinetics

Absorption: Unknown

Distribution: Unknown

Metabolism and Excretion: Unknown

Half-life: Unknown

TIME/ACTION PROFILE

ONSETPEAKDURATION
POunknownunknownunknown

Contraindication/Precautions

Contraindicated in:

  • Hypersensitivity.
  • End stage renal disease.
  • Urinary bladder cancer (may increase risk).

Use Cautiously in:

  • Nephrolithiasis.
  • Hypothyroidism.

Adverse Reactions/Side Effects

CV: insomnia

GI: bloating, constipation, gastrointestinal upset

* CAPITALS indicate life-threatening.
Underline indicate most frequent.

Interactions

Natural Drug Interaction

  •  Antibiotics  may ↓ effects of soy.
  • May inhibit effects of  estrogens and  tamoxifen.
  • May ↑ risk of hypertensive crisis with  MAO inhibitors.
  • May ↓ INR of patients taking  warfarin..

Natural-Natural:

None.

Route/Dosage

PO (Adults): 35–120 mg/day.

Availability

Tablets
Powder

Assessment

  • Monitor BP prior to and periodically during therapy.
  • Hypercholesterolemia: Obtain a diet history, especially with regard to fat consumption.
  • Menopausal symptoms: Assess the frequency and intensity of hot flashes prior to and periodically during therapy.

Lab Test Considerations:

Monitor blood glucose, lipid profile, hormones, and thyroid function before and periodically during therapy.

Implementation

  • PO Administer as directed.

Patient/Family Teaching

  • Instruct patient to take as directed.
  • Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications.

Evaluation/Desired Outcomes

  • Decrease in frequency and intensity of hot flashes.
  • Reduction in serum cholesterol levels.