When it comes to developing a dosing schedule, cannabis has many variables that do not fit in immediately with the typical pharmaceutical drug model. There are a variety of strains of marijuana available, with different effects due to different cannabinoid levels and terpene profiles. Individual patients can also have vastly different tolerance levels, with new users requiring much lower doses to reach the same effect as compared to experienced users. Although it is a potent drug that produces psychoactive effects, THC has very low toxicity, and lethal doses in humans have not been described. Evidence from animal studies and human case reports appears to indicate that the ratio of lethal dose to effective dose is quite large. The theoretical LD50 value is estimated to be 1 to 20,000, using a single cannabis joint as a unit of dose.
Keeping these factors in mind, it is imperative that the dosing model to be used be highly individualized, determined in consultation with the patient and self-titrated. Whether smoking, using a vaporizer or edible items, the general guideline is to start at a low dose, gauge the effects and go slowly. Various surveys published in peer-reviewed journals and medical literature have suggested that the majority of people reported using approximately 1 to 3 grams of dried cannabis per day.
Patients may need to try multiple strains and gauge their relative effects when it comes to symptom relief before deciding on the best choice. Furthermore, some patients may find it useful to use multiple strains throughout the day, switching between them based on time of day. Sativa strains tend to be more energizing and suitable for the daytime, whereas Indica strains are more sedative and helpful with sleeping disorders.
The first time a patient is using medical cannabis, ensure they adhere to the following guidelines:
- Consume their medical cannabis in a safe and comfortable environment
- Have at least 3 hours available to discern the full effects
- Do not have to drive a vehicle or operate any heavy machinery
- Start with a low dose
To provide some perspective, we can look at data from several other clinical trials and studies
- In a randomized controlled trial testing smoked cannabis for chronic neuropathic pain, it was found that inhalation of a single 25mg dose of cannabis four to five times daily resulted in lower levels of pain and improved sleep, which corresponds to 100 – 125mg of THC per day.
- In HIV patients with nausea and vomiting, a study found that regardless of the clinical setting in which it is prescribed, the total recommended dose of dronabinol, a synthetic THC formulation, was 100 to 120 mg/day.
- In a study exploring THC as an antiemetic in cancer patients, it was found that an equivalent of 87.5 mg/day of THC for an average-sized person had a significant reduction in nausea and vomiting.