Thuja

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Note: The archived version of this monograph has been temporarily removed. For an electronic copy of this archived version, please contact the Natural Health Products Directorate (NHPD) at NHPD_DPSN@hc-sc.gc.ca.

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Date: April 25, 2008

Proper name(s): Thuja occidentalis L. (Cupressaceae) (USDA 2007)

Common name(s): Thuja (McGuffin et al. 2000)

Source material(s): Aerial parts (BHP 1983; Felter and Lloyd 1983 [1898])

Route(s) of administration: Oral, topical

Dosage form(s): Those suited to the allowable route(s) of administration.
This monograph does not apply to products for use on mucous membranes.
This monograph is not intended to include food-like dosage forms such as bars, chewing gums or beverages.

Use(s) or Purpose(s): Statement(s) to the effect of:

Oral: Traditionally used in Herbal Medicine as an expectorant to help relieve bronchial catarrh (Hoffmann 2003; Williamson 2003; BHP 1983; Felter and Lloyd 1983 [1898]).

Topical:

• Traditionally used in Herbal Medicine to help remove warts on the hands and feet (Hoffmann 2003; Williamson 2003; BHP 1983; Felter and Lloyd 1983 [1898]).
• Used in Herbal Medicine to help relieve fungal infections (Williamson 2003) such as ringworm (Hoffmann 2003).

Dose(s):

Oral: Preparations equivalent to 1-2 g dried aerial parts, 3 times per day (Williamson 2003; BHP 1983)

Topical: Preparations equivalent to 0.1-2 g dried aerial parts, 3 times per day (Hoffmann 2003; BHP 1983)

Directions for use: Apply to affected area(s).
See Appendix 1 for examples of appropriate dosage preparations, frequencies of use and directions for use, according to cited references. The purpose of Appendix 1 is to provide guidance to industry.

Duration of use:

Oral: For occasional use only (Brinker 2001; McGuffin 1997)

Risk information: Statement(s) to the effect of:

Caution(s) and warning(s):

All routes of administration: Consult a health care practitioner if symptoms persist or worsen.

Oral:

• Consult a health care practitioner prior to use if you are breastfeeding (Brinker 2008).
• Consult a health care practitioner prior to use if you are taking other herbs containing thujone (e.g. wormwood, sage, tansy, and juniper) (Reitjens et al. 2005; Hoffmann 2003).

Topical: Consult a healthcare practitioner prior to use if you have diabetes or poor blood circulation (Berardi et al. 2002).

Contraindication(s):

Oral: Do not use if you are pregnant (Hoffmann 2003; Brinker 2001; BHP 1983).

Known adverse reaction(s): No statement required.

Non-medicinal ingredients: Must be chosen from the current NHPD List of Acceptable Non-medicinal Ingredients and must meet the limitations outlined in the list.

Specifications: Must comply with the minimum specifications outlined in the current NHPD Compendium of Monographs.

References cited:

Berardi RR, DeSimone EM, Newton GD, Oszko MA, Popovich NG, Rollins CJ, Shimp LA, Tietze KJ, editors. Handbook of Nonprescription Drugs: An Interactive Approach to Self-Care, 13^th edition. Washington (DC): American Pharmaceutical Association; 2002.

BHP 1983: British Herbal Pharmacopoeia. Cowling (UK): British Herbal Medical Association; 1983.

Brinker F. Online Updates and Additions to Herb Contraindications and Drug Interactions, 3^rd edition. Sandy (OR): Eclectic Medical Publications; 2008. [Accessed 2008-04-25]. Available from: http://www.eclecticherb.com/emp/updatesHCDI.html

Brinker F. Herb Contraindications and Drug Interactions, 3^rd edition. Sandy (OR): Eclectic Medical Publications; 2001.

Felter HW, Lloyd JU. King's American Dispensatory, Volume 2, 18th edition. Sandy (OR): Eclectic Medical Publications; 1983 [Reprint of 1898 original].

Hoffmann D. Medical Herbalism. Rochester (VT): Healing Arts Press; 2003.

McGuffin M, Hobbs C, Upton R, Goldberg A, editors. American Herbal Products Association's Botanical Safety Handbook. Boca Raton (FL): CRC Press; 1997.

McGuffin M, Kartesz JT, Leung AY, Tucker AO, editors. Herbs of Commerce, 2^nd edition. Silver Spring (MD): American Herbal Products Association; 2000.

Rietjens IM, Martena MJ, Boersma MG, Spiegelenberg W, Alink GM. Molecular mechanisms of toxicity of important food-borne phytotoxins. Molecular Nutrition & Food Research 2005;49(2):131-158.

USDA 2007: ARS, National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Thuja occidentalis L. National Germplasm Resources Laboratory, Beltsville (MD). [Accessed 2008-04-25]. Available from: http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl

Williamson EM. Potter's Herbal Cyclopaedia: The Authoritative Reference work on Plants with a Known Medical Use. Saffron Walden (UK): The C.W. Daniel Company Limited; 2003.

References reviewed:

Burkhard PR, Burkhardt K, Haenggeli CA, Landis T. Plant-induced seizures: reappearance of an old problem. Journal of Neurology 1999; 246(8):667-670.

Stafstrom CE. Seizures in a 7-month-old child after exposure to the essential plant oil thuja. Pediatric Neurology 2007;37(6):446-448.

EC-SCF 2003: European Commission Scientific Committee on Food. Opinion of the Scientific Committee on Thujone. Brussels (B): European Commission Health and Consumer Protection Directorate-General. Scientific Committee on Food. Scientific Committee on Thujone; February 6, 2003, pp. 1-11. [Accessed 2008-04-25]. Available at: www.ec.europa.eu/food/fs/sc/scf/out162_en.pdf

EEC 1988: European Economic Committee. Council Directive 88/388/EEC on the approximation of the laws of the Member States relating to flavourings for use in foodstuffs and to source materials for their production. Brussels (B): European Economic Committee Council Directive 88/388/EEC of 22 June 1988. [Accessed 2008-04-25]. Available at: ec.europa.eu/food/fs/sfp/addit_flavor/flav09_en.pdf

Appendix 1: Examples of appropriate dosage preparations, frequencies of use and directions for use

Oral:

Dried aerial parts: 1-2 g, 3 times per day (Williamson 2003; BHP 1983)

Infusion: 1-2 g dried aerial parts, 3 times per day (Williamson 2003; BHP 1983)

Directions for use: Pour 250 ml of boiling water over dried aerial parts and steep for 10-15 minutes (Hoffmann 2003).

Topical:

Fluidextract: 2 g dried equivalent, 3 times per day
(1:1, 50% alcohol, 2 ml) (BHP 1983)

Tincture:

• 0.2-0.4 g dried equivalent, 3 times per day
  (1:5, 60% alcohol, 1-2 ml) (Hoffmann 2003)
• 0.1-0.2 g dried equivalent, 3 times per day
  (1:10, 60% alcohol, 1-2 ml) (BHP 1983)

Directions for use: Apply to affected area(s).