THC – what medicinal cannabis is good for

Since 2017, as part of an amendment to the Narcotics Act, the use of  cannabis  in medicine has been permitted under strict conditions. This means that a few selected patients in Germany are allowed to buy and use cannabis legally. However, this has little to do with the clichéd idea of ​​smoking weed on prescription. Because numerous studies can prove the scientific benefits of this ancient medicinal plant. This article explains which of the different cannabinoids are used and how they affect our body.

THC, CBD, Cannabis: what is what?

The different names can cause confusion. Cannabis, or hemp in German, is a plant that has been cultivated for thousands of years. Even then, cannabis was used medicinally, for example against pain or  diarrhea .

The hemp plant contains several cannabinoids. This is what the chemical substances are called, one of whose best-known representatives is  tetrahydrocannabinol (THC)  . THC levels vary from strain to strain, making accurate dosing difficult.

In addition to THC, another cannabinoid is important in medicine:  cannabidiol  (CBD). There are more than a hundred different cannabinoids in total, but their exact modes of action are not yet known.

How do cannabinoids work?

There are a variety of cannabinoid receptors distributed throughout our nervous system. This can be imagined as a docking point on the cell surface. If messenger substances – in this case the cannabinoids – reach the receptors, they connect to the cell surface (similar to a key with a lock) and activate the corresponding nerve cell. Cannabinoids can thus trigger a signal in the cell, which leads to a reduced release of the inhibitory neurotransmitter GABA. As a result, a second cell can release more  dopamine  .

However, these receptors are not only used by the cannabinoids supplied “from outside”, substances produced by the body itself also dock onto these receptors. These substances are called endocannabinoids and have a variety of functions in the body. Among other things, they are involved in immune regulation and pain regulation in the brain. For this purpose, they can dock to different receptors in the body. Basically, we have two different receptors:

• Type 1 Cannabinoid Receptors:  Located primarily in the central nervous system (CNS)
• Type 2 cannabinoid receptors:  Located in a wide variety of places in the body, on the digestive organs, the skin, the lungs or the reproductive organs

Just like the endocannabinoids, THC can act in a wide variety of places in the body. In the meantime, it takes over the function of these natural substances.

How does THC affect the body?

The effects of THC on the brain are controlled by the cannabinoid receptors. When cannabis is consumed as a drug (either in the form of marijuana or hashish), the cannabinoids are not yet in their active form. Only when heated does a so-called decarboxylation (splitting of a carbon molecule) take place and thus the conversion into the psychogenic THC.

Among other things, this “promotes” the release of the happiness hormone dopamine in the nucleus accumbens (part of our reward system in the brain). The high levels of dopamine explain the drug’s euphoric effects.

The active ingredient level of THC in the blood is decisive for the different effects. While inhalative applications, such as smoking cannabis flowers, produce high levels of 150-180 nanograms of THC per milliliter of blood, such high doses are avoided in medicine. Most  drugs  provide a THC content of around 10 nanograms per milliliter. This is sufficient for the desired medical effect in terms of pain relief, but is too low to get “high”.

What forms does THC come in medicinally?

In the past, cannabinoids could only be introduced into the body as hashish (pressed resin from the female flowers) or as marijuana (dried flowers). The big problem with this is the different THC content, which can range from 1 to 20 percent. This wide range and possible contamination made this form of cannabis unusable for medicine for a long time.

Today there are various products with THC on the market that can be legally purchased with a prescription. They differ both in their composition and in their area of ​​application:

• Dronabinol:  is administered in the form of oily drops. Dronabinol is a synthetically produced cannabinoid that   can help with loss of appetite .
• Canemes®:  Is a fully synthetic preparation in which THC is used as capsules for chemotherapeutic  nausea  .
• Sativex®:  This drug is used as an oral spray for  multiple sclerosis  . The  active ingredient  nabiximol (a mixture of THC and CBD) is extracted from the cannabis plant.
• Cannabis on prescription:  Since 2017, all doctors (except dentists and veterinarians) have been allowed to prescribe cannabis flowers if there is an indication. Medicinal cannabis is mainly imported from Canada and the Netherlands. In order to achieve the effect, the flowers must be heated beforehand, for example in a vaporizer.
• THC oil:  Very high concentrations of THC can be achieved here, for example with hashish oil a THC concentration of 20 to 60 percent.

Theoretically, it would also be possible to prepare it as a  tea  . However, due to the poor water solubility of THC, this is not possible. The active ingredients in cannabis flowers are lipophilic (fat-loving), which is why they are more likely to be stored in oil.

Cannabis in medicine – where is it used today?

The diverse effects of cannabinoids in our body lead to a wide range of uses for cannabis in medicine. Therapy with medicinal cannabis may be indicated for the following diseases:

• Epilepsy
• Increased appetite in HIV patients
• Nausea and vomiting after  chemotherapy
• chronic pain , especially nerve pain, where all therapies have failed
• in palliative medicine against spasticity in multiple sclerosis

Side Effects of THC

Side effects are particularly psychogenic in nature. Since the mode of action of cannabis has still not been fully researched, no reliable statements can be made about possible side effects. However, various studies have shown that early cannabis use increases the risk of a group of mental illnesses, mood disorders.

Mood and drive changes occur in mood disorders. An example would be the emergence of  bipolar  disorder, in which those affected fluctuate between manic-euphoric and depressive moods.
Other side effects of overdose may include:

• moodiness to the point of  depression
• hallucinations
• Vasodilation (vasodilatation) in the eyes, which leads to the typical redness
• appetite increase
• dry mouth
• Tachycardia  (palpitations)

A major advantage in dosing cannabis is that there are no cannabinoid receptors in our respiratory and cardiovascular centers. For example, an overdose of THC does not lead to life-threatening situations, as can be the case with other painkillers: for example, with an overdose of opioids, the heartbeat slows down to a standstill. In addition, the respiratory center is paralyzed so that the affected person can hardly breathe. In addition, the muscles can literally dissolve and thereby damage the kidney.

Another advantage of cannabis is the lack of psychological dependence when administered in low, medicinal doses.

Cannabis and driving – how long is THC detectable?

THC can only be detected in the blood for a few hours, as it is quickly metabolized by the body into various metabolites (breakdown products). However, these THC metabolites can be detected in urine for more than a few hours, as is the case with drug tests. This is a fairly reliable method of detecting the drug even days after the last consumption.

How is the ability to drive now? In principle, driving under the influence of cannabis is a criminal offence. This has raised the question of whether patients who are prescribed medicinal cannabis for their condition are allowed to drive at all. Here, the federal government decided in April 2017 that those affected may take part in road traffic if their ability to drive is not restricted.

Conclusion: promising, but still some unanswered questions

The use of cannabis in medicine is still in its infancy. There are still too few scientific studies in the field to make reliable statements about the effect. Cannabis is certainly not a miracle drug and it always requires critical scrutiny in treatment. However, isolated cases show promising results.