Cannabis

Products

Hemp and preparations made from it, such as marijuana, cannabis resin, THC, and cannabis extracts, are generally among the prohibited narcotics in many countries. However, the Federal Office of Public Health may grant exemptions for research, drug development and limited medical use. In 2013, a cannabis oral spray (Sativex) was approved as a medicine for the first time in many countries. Additional extemporaneous formulations are prepared in pharmacies. Cannabis seeds are legally available as long as the plants that grow from them have a total THC content of less than 1%. Hemp with a high cannabidiol and a low THC content (<1%) is legally available in many countries, see under cannabidiol hemp and cannabidiol.

Stem plant

Hemp from the hemp family (Cannabaceae) is an annual, herbaceous, and dioecious plant, meaning that a male and female form exists. Pharmacologically, the female plants are of most interest because they produce the inflorescences.

Medicinal drug

Hemp herb (Cannabis herba PH 5) is used as a medicinal drug or intoxicant. This is dried inflorescences and young leaves of the female plant (marijuana). An even higher THC content has the cannabis resin (hashish), which is contained in the herb. Cannabis oil is an oily extract from the resin.

Ingredients

The active ingredients are the cannabinoids, of which over 60 have been identified. The best known cannabinoid is the pharmacologically active lipophilic Δ9-tetrahydrocannabinol (THC), also known medicinally as dronabinol. Cannabidiol (CBD) is not psychoactive but has several interesting pharmacological properties (see under cannabidiol).

Effects

Cannabis has psychotropic, euphoric, depressant, relaxant, antianxiety, antiemetic, appetite stimulant, analgesic, muscle relaxant, and vasodilator properties. The effects are based on the binding of the active ingredients to CB1 and CB2 receptors of the endocannabinoid system. CB1 receptors are found in various centers of the brain. By binding to CB receptors, cannabinoids inhibit the release of neurotransmitters from the presynaptic neuron, among other effects.

Indications for use

The flowers and resin are used as intoxicants. They are usually smoked as a joint, inhaled with hookahs or e-cigarettes, or supplied via other routes (e.g., space cakes). Possible medical uses (selection):

Contraindications

  • Hypersensitivity
  • Suicidality or suicidal ideation
  • History or family history of schizophrenia or other psychosis
  • History of severe personality disorder or other significant psychiatric disorder
  • Pregnancy and lactation

Full precautions can be found in the drug label.

Interactions

Tetrahydrocannabinol is metabolized by CYP isozymes. Corresponding drug-drug interactions with CYP inducers and CYP inhibitors are possible. Other interactions may occur with central depressant drugs, antispastic agents, and alcohol, among others.

Adverse effects

Cannabis can lead to dependence, tolerance, and withdrawal symptoms with long-term and high-dose use. Compared with other narcotics, the lethal dose is high (THC: between 15 to 70 g). The observed side effects are dose-dependent: