Yerba Santa - Drug Monograph

Introduction

Yerba Santa (Eriodictyon californicum) is a traditional medicinal plant native to California and northern Mexico. While not an FDA-approved pharmaceutical drug, it has been used for centuries by indigenous communities and in herbal medicine for various respiratory and inflammatory conditions. This monograph provides evidence-based information on its potential therapeutic applications and safety considerations.

Mechanism of Action

Yerba Santa contains several bioactive compounds including eriodictyol, homoeriodictyol, and flavonoids. The primary proposed mechanisms include:

• Mucolytic and expectorant effects: Flavonoids may stimulate respiratory tract secretions and reduce mucus viscosity
• Bronchodilatory activity: Potential relaxation of bronchial smooth muscle
• Anti-inflammatory properties: Modulation of inflammatory pathways through flavonoid content
• Antioxidant effects: Free radical scavenging activity due to phenolic compounds

Indications

• Respiratory congestion associated with colds and bronchitis
• Symptomatic relief of asthma symptoms
• Traditional use for fever reduction
• Topical application for pain relief and wound healing

Dosage and Administration

• Tea/infusion: 1-2 teaspoons dried leaves in 8 oz water, 1-3 times daily
• Tincture (1:5): 2-4 mL three times daily
• Syrup: As directed on product labeling

• Pediatrics: Safety not established
• Geriatrics: Use with caution due to limited safety data
• Hepatic/renal impairment: No dosage recommendations available

Pharmacokinetics

Contraindications

• Known hypersensitivity to Yerba Santa or related plants in the Hydrophyllaceae family
• Pregnancy (due to lack of safety data)
• Breastfeeding (due to lack of safety data)

Warnings and Precautions

• Not evaluated by FDA for safety or efficacy
• Potential for allergic reactions in sensitive individuals
• Use caution in patients with hormone-sensitive conditions (theoretical concern due to flavonoid content)
• Discontinue use 2 weeks prior to elective surgery due to theoretical antiplatelet effects

Drug Interactions

• Anticoagulants/antiplatelets: May potentiate effects (flavonoid content)
• Antihypertensive drugs: Possible additive effects
• Diabetes medications: May affect blood glucose levels
• CYP450 substrates: Potential inhibition due to flavonoid content

Adverse Effects

• Gastrointestinal discomfort
• Allergic reactions in sensitive individuals

• Anaphylaxis (rare)
• Hepatotoxicity (theoretical, no documented cases)

Monitoring Parameters

• Respiratory symptom improvement
• Signs of allergic reactions
• Liver function tests with prolonged use
• Bleeding parameters if used with anticoagulants

Patient Education

• This is a traditional herbal remedy, not an FDA-approved medication
• Inform healthcare providers about all herbal product use
• Discontinue use if rash, difficulty breathing, or other adverse effects occur
• Not recommended during pregnancy or breastfeeding
• Keep out of reach of children
• Purchase from reputable sources to ensure product quality

References

1. Felger RS, Moser MB. "Eriodictyon californicum" in: Native American Ethnobotany. Timber Press; 1998. 2. Wichtl M. Herbal Drugs and Phytopharmaceuticals. CRC Press; 2004. 3. Blumenthal M, et al. The ABC Clinical Guide to Herbs. American Botanical Council; 2003. 4. Natural Medicines Comprehensive Database. Yerba Santa Monograph. Therapeutic Research Center; 2021. 5. USDA Phytochemical and Ethnobotanical Databases. Beltsville Agricultural Research Center. 6. European Medicines Agency. Assessment report on Eriodictyon californicum. EMA/HMPC/228779/2012.