There are different types of CBD products, and the different labels and formulations are important when storing these items at the pharmacy, Fixen said. Full-spectrum CBD is made from the plant itself, not synthetically. It contains other cannabinoids and trace amounts of THC. Similarly, broad spectrum CBD contains other cannabinoids but no THC. Finally, the CBD isolate is made by extracting the plant material and removing naturally occurring elements, and it often uses harsh or toxic chemicals.
Hemp, on the other hand, contains CBD but is more difficult to extract and contains less than 0.3% THC, Fixen said. In particular, pharmacists should know that hemp oil is not the same as CBD oil.
The endocannabinoid system (ECS) is a complex cell signal system that regulates and balances many processes. It is made up of endocannabinoids, including anandamide (AEA) and 2-arachidonoylglycerin (2-AG). Pharmacists should consider the ECS when discussing CBD products with patients for many reasons, but most importantly because it modulates dopamine, serotonin, glutamate, norepinephrine, gamma-aminobutyric acid, and acetylcholine.
Fixen also discussed the cannabinoid receptors CB1, which control the central nervous system, spinal cord, peripheral nervous system, peripheral tissues and organs, and CB2, which affects the gastrointestinal tract, immune cells, and peripheral tissues. CBD is an indirect antagonist of CB1 and CB2 agonists and is highly lipophilic with a high volume of distribution. It is metabolized by CYP3A4 and CYP2C9 and inhibits CYP2C19 and CYP2D6. According to Fixen, CBD has a half-life of 18 to 32 hours and poor oral absorption at only 12% to 18%.
Patients should be aware of the side effects, which may include nausea, diarrhea, headache, drowsiness or sedation, tiredness, and dry mouth. It can increase the effects of alcohol, anti-epileptics, antipsychotics, benzodiazepines, beta blockers, opioids, selective serotonin reuptake inhibitors, and warfarin.
The use of CBD has been hotly debated in recent years both because of these potential adverse effects and because it is relatively unregulated. In 2019, the FDA issued a warning that CBD could be potentially harmful, with serious effects such as liver damage, altered metabolism of other drugs, male reproductive toxicity, and increased sedation, according to Fixen. Despite its potential therapeutic benefits, researchers have also suggested that it could have adverse cardiovascular effects.
When choosing CBD products to be shipped to the pharmacy or recommended to patients, the Doctors of Fixen should demonstrate a framework and consider different methods of administration. Common CBD delivery methods include inhaled products, suppositories, oral products, and topical creams or patches.
Inhaled formulations have an immediate onset and maximum effect in 30 minutes and last up to 2 hours, Fixen said. It’s easier to dose because the effects are instant, although Fixen said vaporizing is typically preferred over smoking. Suppositories also start quickly and can take between 4 and 6 hours. When pharmacists inform patients of this option, they should be aware that some suppository products must be kept in the refrigerator.
Oral tablets and capsules start between 1 and 6 hours and last from 6 to 8 hours. Fixen said these products might be a better option for patients seeking long-term relief, and patients should be advised that oral options increase peak concentrations when taken with a high-fat or high-calorie meal.
Sprays and sublingual options are less effective, between 15 and 120 minutes. They are dosed with a pipette, syringe, spray or sublingual tablet and are based on oil with coconut, olive or sesame oil. Sublingual absorption reaches a more rapid onset, although it should be noted that tinctures can contain anywhere from 10% to 40% alcohol.
Finally, Fixen outlined some basic standards to adhere to when considering CBD products. Pharmacists should recommend products made in a state that legalizes recreational and medicinal use of cannabis that are full or broad spectrum CBD oil extract that have a certificate of analysis and labeling which shows the amount of CBD per serving, and CBD, which is obtained from high-resin cannabis.
Products should not be considered if they come from a foreign source. isolate, distill, or say “pure CBD”; list only total cannabinoid content; and come from the seed or stem of a hemp plant.
By carefully weighing pharmacokinetics, potential side effects, and appropriate products for their patients, pharmacists can effectively advise their patients on safe products and appropriate use.
Fixen D. The ABCs of CBD Products and Practices; American Pharmacists Association Annual Meeting and Exhibition 2021. March 12, 2021.