What doses are used if THC (dronabinol) or cannabis is ingested, in capsules, in cookies or as cannabis tea?
If possible, slowly increasing doses should be applied in a titrated fashion to avoid undesirable side effects on psyche and circulation. Starting doses are 2 x 2.5 mg or 2 x 5.0 mg of dronabinol per day. Dosages may be increased up to several units of 10 mg daily. In appetite loss and nausea due to AIDS 5-20 mg THC daily are usually sufficient, pain treatment may often need higher doses. If natural cannabis products of unknown THC content are used orally, the patient should begin with about 0.05-0.1 grams of the drug (for cannabis with an average THC content of 5 percent this corresponds to 2.5-5 mg THC). If the THc content is unknown, a store of cannabis sufficient for several weeks should be layed in so that a constant quality is ensured. In a study by Fairbairn and colleagues (1976) the THC content of marijuana only decreased by 7% within 47 weeks with dark, dry storage at 5°C, and by 13% at a temperature of 20°C.
To achieve reproducible effects cannabis or THC should be ingested always under similar conditions with regard to food intake, e.g. always one hour before a meal. If natural cannabis preparations are used doses should be weighed carefully and taken with the same carrier, e.g. cannabis tea with half a gram of dried cannabis flowers on half a liter of water and some cream.
As with opiates, some side effects may decrease within some days or weeks, thereby increasing the acceptance of the drug. Prolonged THC ingestion causes tolerance to unwanted effects on circulation and to psychological effects, so that daily doses of more than 50 mg THC may sometimes be taken without significant unwanted psychic or physical side effects. Heavy regular users in western societies may smoke five to ten cannabis cigarettes per day or more, thus well tolerating daily doses of 100 mg THC and more. In a sample of cannabis users analyzed by Solowij (1991) mean weekly consumption was 766 mg THC, ranging from 30-2400 mg THC.
Tolerance may also arise with respect to therapeutically desired effects (e.g. decrease of intraocular pressure, pain reduction), and require increased doses after some time of treatment.
Modified according to: Grotenhermen F. Harm reduction associated with inhalation and oral administration of cannabis and THC. Journal of Cannabis Therapeutics 2001;1(3-4):133-152.