The medical benefits of cannabis and THC

Most of the medicinal effects of cannabis products are based on the cannabinoid delta-9-tetrahydrocannabinol, or delta-9-THC or THC. It is also called dronabinol in a medical context. In recent years, the effects of other components of the cannabis plant have come into focus, including cannabidiol (CBD), tetrahydrocannabivarin (THCV), some other cannabinoids and terpenes (essential oils).

This part of the course deals with the effects of THC and THC-rich cannabis strains. More than ten cannabinoids belong to the delta-9-THC type, of which mainly two delta-9-THC acids are found in the plant, which are converted into the phenolic delta-9-THC under the influence of heat. This phenolic THC (dronabinol) causes the well-known psychological effects of cannabis and is also responsible for many pharmacological effects of the hemp plant. THC binds to the two known cannabinoid receptors CB1 and CB2. When the CB1 receptor is activated by THC, this causes pain relief, muscle relaxation, increase in appetite, bronchial dilation, inhibition of nausea, increase in heart rate and many other effects. The activation of the CB2 receptor by THC inhibits inflammation and allergic reactions.

Possible uses for cannabis and THC are for the following diseases and symptoms.

• Nausea and vomiting: Cancer chemotherapy, HIV/Aids, hepatitis C, pregnancy vomiting, nausea in the context of migraine.

• Loss of appetite and emaciation: HIV/Aids, advanced cancer, hepatitis C.

• Spasticity, muscle cramps (spasms), muscle hardening: multiple sclerosis, paraplegia, spasticity after stroke, tension headache, intervertebral disc problems and tension in the back muscles.

• Movement disorders with an excess of movement (hyperkinetic movement disorders): Tourette's syndrome, dystonia (for example, spastic torticollis or eyelid spasm), dyskinesias triggered by treatment with levodopa in Parkinson's disease, tardive dyskinesias (a possible side effect of neuroleptics used in schizophrenia), essential tremor (tremor).

• Pain: Migraine, cluster headache, phantom limb pain, neuralgia (nerve pain, for example, sciatica), menstrual cramps, paraesthesia (tingling, burning, formication) in diabetes or AIDS, hyperalgesia (increased sensitivity to pain), pain in tight muscles and muscle spasms, osteoarthritis, fibromyalgia (soft tissue rheumatism).

• Allergies: Asthma, hay fever.

• Itching: severe itching in liver disease, neurodermatitis.

• Inflammations: Asthma, arthritis, rheumatism, ulcerative colitis, Crohn's disease (a chronic inflammation of the bowel), neurodermatitis, psoriasis.

• Restless legs syndrome.

• Mental illnesses: Depression, anxiety disorders, bipolar disorder (manic-depressive disorder), post-traumatic stress disorder (PTSD), attention deficit hyperactivity disorder (ADHD), impotence, alcoholism, opiate addiction, sleeping pill addiction, insomnia, autism, confused behaviour in Alzheimer's disease.

• Overproduction of stomach acid: gastritis.

• Increased intraocular pressure: glaucoma (green star).

• Increased tendency to sweat (hyperhidrosis).

• Tinnitus (ringing in the ears).

• Dilatation of the bronchial tubes: asthma, shortness of breath in other respiratory diseases.

• Epilepsy.

• Singultus (hiccups).

• File inversa.

• Promotion of contractions during childbirth.

For some of these conditions and symptoms, especially spasticity in multiple sclerosis, chronic neuropathic pain, loss of appetite in HIV/AIDS and nausea due to cancer chemotherapy, there are large controlled clinical trials that demonstrate efficacy. For most of the above indications, there are only small, often uncontrolled studies or case reports.