Editor, – Preparations of guarana from the South American tree Paullinia cupana are sold over the counter in pharmacies in Australia in several forms. These include a powder form derived from ground seeds (Rio Amazon Guarana powder for drinks) and a spearmint flavoured gum containing guarana extract (Go Gum). Advertising information on the displays in pharmacies and the packaging includes: 'Catch a buzz, naturally', 'Great for divers, athletes, students, night staff, busy mums' and 'the secret ingredient ... puts dynamite into juices, mixes and punch'. It also states that the powder may 'be used in cakes or cookies'.
Nowhere on the packaging does it list the chemical constituents of guarana. The main constituent in guarana that allows you to 'Catch a buzz, naturally' is caffeine. In fact, guarana seeds contain between 3 and 5 times the caffeine in terms of dry weight than Arabica coffee beans, and ground guarana seeds have long been used to make a stimulating beverage by indigenous peoples. More recently, guarana has been used in Europe as a stimulant at all-night 'techno-parties'.1 The release and absorption of caffeine from guarana preparations has been shown to be equivalent to that of preparations of caffeine alone in animal studies.2
Caffeine is contraindicated in conditions such as anxiety states and some cardiovascular disorders, and symptoms associated with the stimulant effect of caffeine or caffeine withdrawal may create diagnostic problems for clinicians that are unaware of the presence of caffeine in the marketed preparations of guarana. Aqueous extracts of guarana have also been shown to have antiplatelet activity3,4, so possibly guarana should be avoided during anticoagulant therapy.
This raises a couple of important issues. Firstly, well-known chemical constituents of herbal preparations such as caffeine should be documented on the packaging so consumers can make an informed choice about what they are buying. Secondly, in the context of increasing use of herbal remedies, perhaps medical practitioners should have easier access to information on the pharmacological activities, potential drug interactions and chemical constituents of these products. A reply from the Therapeutic Goods Administration clarifying these issues would be appreciated.
Mark Myerscough
General Practitioner
Tiwi, N.T.
Laurayne Bowler, Acting Branch Head, Chemicals and Non-Prescription Drugs Branch, Therapeutic Goods Administration, comments:
The Therapeutic Goods Administration (TGA) has noted the concern raised with regard to products containing Paullinia cupana (guarana). Paullinia cupana may be included in both foods and therapeutic goods. When included in foods, the herb is regulated through the Australia New Zealand Food Authority (ANZFA). State and Territory health authorities monitor compliance of foods with the Food Standards Code. The TGA will seek expert advice on the need for a label warning statement, a declaration of caffeine content or other appropriate action in relation to products containing Paullinia cupana.
