Question 1

How does Nandina domestica work as a cough suppressant?

Accepted Answer

Nandina domestica contains isoquinoline alkaloids, particularly nantenine and domesticine, which act on the central nervous system to suppress the cough reflex. Berberine contributes additional antimicrobial and anti-inflammatory effects. The antitussive mechanism involves modulation of cough receptor sensitivity and central cough center activity. These compounds work synergistically to reduce cough frequency and intensity. Evidence level: C (preclinical and traditional use data).

Question 2

Does Nandina domestica interact with any medications?

Accepted Answer

Nandina domestica contains berberine and other alkaloids that may interact with cytochrome P450 enzymes, potentially affecting metabolism of various medications. It may enhance effects of sedatives and CNS depressants due to its mild sedative properties. Those taking antihypertensives, anticoagulants, or liver-metabolized medications should exercise caution. Evidence level: C. Consult a healthcare provider before combining with prescription medications.

Question 3

What is the recommended dosage for Nandina domestica?

Accepted Answer

The traditional adult dosage for Nandina domestica dried fruit is 3-6 grams daily, typically prepared as a tea or decoction. In Japanese Kampo medicine, it is often combined with other herbs in standardized formulations. Dosage should not exceed recommended amounts due to alkaloid content. Evidence level: C (traditional use). Always follow practitioner guidance, as individual needs may vary based on condition and constitution.

Question 4

Is Nandina domestica safe during pregnancy?

Accepted Answer

Nandina domestica is contraindicated during pregnancy and breastfeeding. The plant contains alkaloids including berberine, domesticine, and nantenine, which may stimulate uterine contractions and pose risks to fetal development. Traditional Japanese Kampo sources explicitly warn against use in pregnant women. Evidence level: C. Women who are pregnant, nursing, or planning pregnancy should avoid this herb entirely.

Question 5

What is Nandina domestica used for in traditional medicine?

Accepted Answer

Nandina domestica is primarily used in Japanese Kampo medicine as an antitussive for treating coughs and respiratory infections. Traditional applications include whooping cough, bronchitis, and asthma. The dried fruit is the primary medicinal part, valued for its cough-suppressing and antimicrobial properties. It has been used for centuries in East Asian medicine. Evidence level: C (traditional and preclinical evidence).

Question 6

What are the side effects of Nandina domestica?

Accepted Answer

Common side effects include gastrointestinal upset such as nausea, vomiting, and diarrhea due to alkaloid content. Mild sedation or drowsiness may occur. Higher doses can cause more severe symptoms including respiratory depression. The herb is contraindicated in children due to potential alkaloid toxicity. Evidence level: C. Discontinue use if adverse effects occur and consult a healthcare provider.

Nandina Domestica Herb

Sources & Citations

Prunus avium

Solanum xanthocarpum

Lentibularia vulgaris

Summary

Background

Traditional uses

Active compounds

Mechanism of action

Clinical evidence

Safety & adverse effects

Evidence summary

PubMed sources

Government sources