Herbal Preparations of Medical Cannabis: A Vademecum for Prescribing Doctors

Abstract

Cannabis has been used for centuries for therapeutic purposes. In the last century, the plant was demonized due to its high abuse liability and supposedly insufficient health benefits. However, recent decriminalization policies and new scientific evidence have increased the interest in cannabis therapeutic potential of cannabis and paved the way for the release of marketing authorizations for cannabis-based products. Although several synthetic and standardized products are currently available on the market, patients’ preferences lean towards herbal preparations, because they are easy to handle and self-administer. A literature search was conducted on multidisciplinary research databases and international agencies or institutional websites. Despite the growing popularity of medical cannabis, little data is available on the chemical composition and preparation methods of medical cannabis extracts. The authors hereby report the most common cannabis preparations, presenting their medical indications, routes of administration and recommended dosages. A practical and helpful guide for prescribing doctors is provided, including suggested posology, titration strategies and cannabinoid amounts in herbal preparations obtained from different sources of medical cannabis.

Oral Administration of Cannabis and Δ-9-tetrahydrocannabinol (THC) Preparations: A Systematic Review

“…From a therapeutic perspective, oral cannabis intake is promising due to its long-lasting drug effects, easy administration, and reduced toxicity derived from pyrolytic by-products. To date, the limited information available describes a slow and erratic absorption, seemingly showing higher bioavailability in oil formulations [ 24 ].…”

“…Several medical products with marketing authorization contain THC as their main component, including dronabinol (synthetic THC), commercialized as oral capsules (Marinol ® ) or as an oral solution (Syndros ® ), and nabilone (a synthetic THC analogue), which is marketed as oral capsules (Cesamet ® or Canemes ® ). Nabiximols (Sativex ® ), available as a buccal spray, also includes CBD in its formulation [ 14 , 24 , 25 , 26 ]. However, few cannabis products have sufficient evidence to obtain approval for therapeutic use in the USA and several European countries.…”

Chronological Review and Rational and Future Prospects of Cannabis-Based Drug Development

“…The identified synergistic interactions between cannabis molecules might be the “entourage effect” reported for cannabis preparations, as synergistic effects activate new biological pathways not activated by the components in isolation [ 33 , 35 ]. Importantly, herbal preparations of cannabis, cannabis varieties for use in medical preparations, and guidelines for prescribing doctors including physician’s recommendations, dosages, and titration strategies were recently reviewed in [ 36 ]. However, the incomplete understanding (for now) of the mechanism behind this “entourage effect” in cannabis preparations makes it difficult to follow regular drug development and approval procedures (discussed below).…”

“…Registering one, a few, or multiple molecules as drugs is a challenging task. Despite the synergistic effect of plant extracts over single compounds, traditional medicines based on whole plants, herbal extracts, or mixtures cannot be recognized as certified drugs as they are non-registerable [ 36 , 57 ]. Registerable drugs are based on known amounts of pure compounds, which can be synthesized and recombined and, thus, registered as formulated medicines.…”

“…As for the future, we appreciate the aspects involved in cannabis-based drug development, such as complex entourage effects and terpene considerations [ 33 , 34 , 35 , 36 , 37 ]. We also acknowledge the current difficulties of the pharma industry to include natural preparations, as discussed above.…”