Bioavailability can simply be defined as “The degree to which drugs or other substance becomes available to target issue after administration” (The American Heritage Medical Dictionary). There are a number of factors that can influence the bioavailability of Marijuana but it mostly depends on how it is taken. There are plenty of ways to take medical marijuana, but often what is confusing is to find out the way that will work best for you.
People normally smoke marijuana inhale it from vapor, brew as tea, apply as
balm or even eat it in products like chocolate bars. Some of the factors that everyone needs to take care of is the safety of the method as well as the product’s flavor, the ingredients used in its creation, and its overall strength.
Medical marijuana means whole marijuana or its ingredientslike Cannabidiol (CBD), delta-9-tetrahydrocannabinol (THC) which forms the base of a limited number of approved medications. Some studies show CBD may be useful for relieving severe pain, inflammation, nausea and other chronic conditions. On the other hand, THC is a psychedelic substance present in marijuana that acts on specific brain receptors, causing possible mood changes, depression, memory issues, reduced aggression and other disruption in learning abilities. It can also affect the sense of smell, hearing and eyesight and may as well cause fatigue in some people.
Any drugs/substance provided intravenously is assumed to have 100% bioavailability while other administration is compared to the intravenous route as the ratio for percentage bioavailability. Studies show that CBD and THC have somewhat similar bioavailability.
Oral administration of medical marijuana
An oral route of administration of medical marijuana is the most common route used by most people. It is one of the easiest ways to consume marijuana. This is due to the fact that cannabinoids can be incorporated into many food products and can also be consumed in capsules. A recent study on a small number of participants has shown 6% of bioavailability when the consumed servings of 40 mg of CBD are mixed in chocolate cookies.
First-pastmetabolism or First-pass effect is one of the main reasons for low oral bioavailability. It is caused due to enzymes present in the digestive system before CBD reaches the blood. Enzymes in the liver called CYP450 acts with CBD to yield more than 100 different metabolites. Several of the metabolites cannot be used by the body and are spelled as waste from the body. Taking CBD with medium and long-chain triglycerides (fatty acids) can help to enhance bioavailability. These fatty acids have the ability to bypass some first-pass metabolism.
People consuming marijuana for medical purposes such as chronic pain prefer oral injection as none of the products are lost and it lasts longer compared to others. However, marijuana taken from oral injection has a high time of effect onset making it difficult to titrate dosage.
Inhalation of medical marijuana
Inhalation is the fastest method of delivery to any user. A huge portion of people prefers using marijuana this way. The effect of inhalation is almost instant. For some people using marijuana for medical purposes, this is very effective like that of an inhaler for an asthma attack. One of the best benefits of inhalation is the ability to easily titrate the dose, resulting in less over consumption.
Marijuana is often taken for recreational purposes rather than therapeutic ones. Inhalation of medical marijuana has some benefits in terms of achieving higher bioavailability when compared with oral administration. This is the main reason why people feel psychoactive results of THC faster with inhalation as compared to taking them orally. Research has estimated that the bioavailability of THC after inhalation was 18% and 40% when marijuana was vaporized instead of combusted.
The reason why there is high bioavailability in the case of inhalation is due to the fact that lungs have high permeability. They provide a large absorption area and a good supply of blood for cannabinoids to enter into circulation and bypassing the first-pass metabolism from the digestive system.
Rectal administration of medical marijuana
Scientific reports from researches on rectal administration of medical marijuana are conflicting. According to a physician who conducted and wrote about the absorption of cannabis, nothing was felt by his test patients when they used cannabis oil in cocoa butter. Their plasma analysis
revealed negligible CBD and THC levels. Marijuana doctors says components must dissolve into aqueous mucus that line rectum and pass into the bloodstream in order to be absorbed directly. Cannabinoids should not be mixed with a fatty carrier if they are supposed for rectal use. This because doing so will reduce their overall absorption.
Rectal administration might be perfect for those under going chemotherapy; having nausea which makes it often impossible for them to digest marijuana
edibles, says a prominent group of marijuana doctors. Moreover, this can be beneficial to the surgical patient who cannot eat immediately before and after surgery and also for patients who are unable to swallow. This form of administration is also ideal for a person who doesn’t want to have any psychoactive effects but wants to consume THC.
A study showed that the chemically modified version of THC, called THC- hemi succinate (THC-HS), is bioavailable in the rectum. This is because THC-HS is water-soluble which makes it easy to be absorbed through the rectal mucosa. Dr. Paula-Noel Macfie created BackDoor Medicine, a group with the aim of having cannabis suppository education. She mentions that marijuana has 15-25% and 25-30% bioavailability when smoked and inhaled espectively. However, after rectal administration, 75-80% of the cannabinoids become bioavailable. Cannabinoids may give effect via local pathways in the colons, but these parts have not been scientifically studied and verified. Far more research is required for better understating of exactly how this method works or not. You don’t need to wait until all the researches are in. If you are curious, then it could be worth a try.
The bioavailability of cannabinoids is still the thing that researchers are working out to understand completely. Various studies conducted
often produce different percentages of bioavailability. This makes finding an
administration method and desired number for medical marijuana difficult.
Rather than focusing on bioavailability, choose the method which makes you feel more comfortable.