Cannabis - THC

Drug interactions may result from chemical reactions between different  components or modifications by certain components of certain biochemical  pathways involved in the action or metabolism of related drugs.  According to Drugs.com, drug interactions can be affected by various factors including disease  and patient conditions, as well as the nature of the compounds involved.  A drug interaction may lead to an enhanced drug response or modified or unexpected adverse reactions.  Use of medical cannabis or cannabis preparations is generally considered  safe and is devoid of common major adverse reactions, although rare  cardiovascular adverse effects and stroke have been noted. Tolerance and  dependence have been documented. Major adverse reactions with  recreational cannabis use occur more with increasing dosages and include  cardiovascular effects, cannabinoid hyperemesis syndrome, psychosis,  and others. 

Most reported drug interactions are pharmacokinetic ones, e.g., through  affecting drug metabolism enzymes such as cytochrome P450 (CYP450). 

THC can decrease serum concentrations of clozapine, duloxetine, naproxen, cyclobenzaprine, olanzapine, haloperidol, and chlorpromazine. 

 Contraindications have not been identified. There is a risk of  hypersensitivity to marijuana or other constituents of the plant. The  benefits versus risks of cannabis use should be carefully weighed in  individuals with psychosocial disorders.  According to Drugs.com a total of 339 drugs are known to interact with cannabis.

View most common interaction reports for cannabis and the medicines listed below.

• Adderall (amphetamine / dextroamphetamine)
• Alcohol (contained in alcoholic beverages) (ethanol)
• amitriptyline
• Ativan (lorazepam)
• Benadryl (diphenhydramine)
• Cymbalta (duloxetine)
• Fish Oil (omega-3 polyunsaturated fatty acids)
• Flexeril (cyclobenzaprine)
• ibuprofen
• Klonopin (clonazepam)
• Lexapro (escitalopram)
• Lyrica (pregabalin)
• morphine
• Paracetamol (acetaminophen)
• Seroquel (quetiapine)
• tramadol
• Tylenol (acetaminophen)
• Vitamin B12 (cyanocobalamin)
• Vitamin C (ascorbic acid)
• Vitamin D3 (cholecalciferol)
• Wellbutrin XL (bupropion)
• Xanax (alprazolam)
• Zofran (ondansetron)
• Zoloft (sertraline)
• Zyrtec (cetirizine)  

Drug interactions can occur when two or more drugs/substances with  similar or different actions (including herbal substances) are  co-administrated, such as warfarin with aspirin, and cyclosporine A with  St John’s Wort. Drug interactions may result from chemical reactions  between different components or modifications by certain components of  certain biochemical pathways involved in the action or metabolism of  related drugs.  There are early studies or case reports indicating potential drug  interactions with warfarin, oxymorphone, pentobarbital, cocaine,  sympathomimetic amines, disulfiram, disulfiram etc., but further  research is needed. Interestingly, Russo (2016) mentioned that in  extensive clinical application including complex drug regimens with  opioids, tricyclic antidepressants, anticonvulsants etc, no drug  interactions have been observed that would contraindicate or preclude  the use of nabiximols with any specific pharmaceutical, although  additive sedative effects are always possible. 

MacCallum & Russo (2018) recently pointed out that there is no drug that cannot be used with cannabis, if necessary.

This entourage effect  is the concept that the different compounds in cannabis—such as terpenes, tetrahydrocannabinol (THC) and cannabidiol (CBD)—could interact with each other to produce synergistic effects.  Much like a musical instrument that joins with other instruments begin to form a symphony that creates a unique sound.  In addition to being found in cannabis, terpenes are found in many plants, including fruits and vegetables. As fragrant compounds, they’re responsible for the aromas in essential oils and different cannabis strains.  Terpenes are found in both food and cannabis, some have speculated that consuming certain terpenes could change the cannabis “symphony,” leading to a different type of medicine and feeling/high.

According to Drugs.com, cannabis might increase the effects of alcohol.  Alcohol can increase the nervous system side effects of cannabis  (Schedule I substance) such as dizziness, drowsiness, and difficulty  concentrating.  Some people may also experience impairment in thinking  and judgment.  You should avoid or limit the use of alcohol while being  treated with cannabis (Schedule I substance).  Do not use more than the  recommended dose of cannabis (Schedule I substance), and avoid  activities requiring mental alertness such as driving or operating  hazardous machinery until you know how the medication affects you.  Talk  to your doctor or pharmacist if you have any questions or concerns. 

While grapefruit is a nutritious fruit, many patients are concerned about the potential  for drug interactions with grapefruit juice. Maybe you've receive a  medication prescription container with an affixed warning label that  recommends you avoid grapefruit or grapefruit juice while taking the  medication.  

GENERALLY AVOID:  Alcohol may potentiate some of the pharmacologic  effects of CNS-active agents.  Use in combination may result in additive  central nervous system depression and/or impairment of judgment,  thinking, and psychomotor skills.
 

MANAGEMENT:  Patients receiving CNS-active agents should be warned of  this interaction and advised to avoid or limit consumption of alcohol.   Ambulatory patients should be counseled to avoid hazardous activities  requiring complete mental alertness and motor coordination until they  know how these agents affect them, and to notify their physician if they  experience excessive or prolonged CNS effects that interfere with their  normal activities. 

Marijuana, which can also be called weed, pot, dope, or cannabis, is the  dried flowers and leaves of the cannabis plant. It contains  mind-altering (e.g., psychoactive) compounds like tetrahydrocannabinol,  or THC, as well as other active compounds like cannabidiol, or CBD, that  are not mind-altering. 

There are many ways of using marijuana, and each one affects users  differently. Marijuana can be rolled up and smoked like a cigarette (a  joint) or a cigar (a blunt). Marijuana can also be smoked in a pipe.  Sometimes people mix it in food and eat it or brew it as a tea  (edibles). Smoking oils, concentrates, and extracts from the marijuana  plant are on the rise. People who use this practice call it “dabbing.” 

 Like any other drug, marijuana’s effects on a person depends on a number  of factors, including the person’s previous experience with the drug or  other drugs, biology (e.g., genes), gender, how the drug is taken, and  how strong it is. 

The marijuana plant has chemicals that may help symptoms for some  health problems. More and more states are making it legal to use the  plant as medicine for certain conditions. But there isn’t enough  research to show that the whole plant works to treat or cure these  conditions. Also, the U.S. Food and Drug Administration (FDA)External has not recognized or approved the marijuana plant as medicine.

Because marijuana is often smoked, it can damage your lungs and  cardiovascular system (e.g., heart and blood vessels). These and other  damaging effects on the brain and body could make marijuana more harmful  than helpful as a medicine. Another problem with marijuana as a  medicine is that the ingredients aren’t exactly the same from plant to  plant. There’s no way to know what kind and how much of a chemical  you’re getting.

Two medicines have been made as pills from a chemical that’s like  THC, one of the chemicals found in the marijuana plant that makes people  feel “high.” These two medicines can treat nausea if you have cancer  and make you hungry if you have AIDS and don’t feel like eating. But the  chemical used to make these medicines affects the brain also, so it can  do things to your body other than just working as medicine.

Another marijuana chemical that scientists are studying, called  cannabidiol (CBD), doesn’t make you high because it acts on different  parts of the nervous system than THC Scientists think this chemical  might help children who have a lot of seizures (when your body starts  twitching and jerking uncontrollably) that can’t be controlled with  other medicines. Some studies have started to see whether it can help.

According to the U.S. CDC: Yes, about 1 in 10 marijuana users will become addicted. For people who  begin using younger than 18, that number rises to 1 in 6.1-3 For more information visit CDC’s section on addiction or the National Institute on Drug Abuse’s pages on addiction science. 

Marijuana is the most commonly used illegal drug in the United States, with 37.6 million users in the past year, and marijuana use may have a wide range of health effects on the body and brain. 

Experts developed 10 major recommendations for lower-risk use: 

(1) the most  effective way to avoid cannabis use–related health risks is abstinence,  

(2) avoid early age initiation of cannabis use (i.e., definitively  before the age of 16 years), 

(3) choose low-potency tetrahydrocannabinol  (THC) or balanced THC-to-cannabidiol (CBD)–ratio cannabis products, 

(4)  abstain from using synthetic cannabinoids, 

(5) avoid combusted cannabis  inhalation and give preference to nonsmoking use methods, 

(6) avoid  deep or other risky inhalation practices, 

(7) avoid high-frequency  (e.g., daily or near-daily) cannabis use, 

(8) abstain from  cannabis-impaired driving, 

(9) populations at higher risk for cannabis  use–related health problems should avoid use altogether, and 

(10) avoid  combining previously mentioned risk behaviors (e.g., early initiation  and high-frequency use). 

According to the CDC:  A fatal overdose is unlikely, but that doesn’t mean marijuana is  harmless. The signs of using too much marijuana are similar to the  typical effects of using marijuana but more severe. These signs may  include extreme confusion, anxiety, paranoia, panic, fast heart rate,  delusions or hallucinations, increased blood pressure, and severe nausea  or vomiting. In some cases, these reactions can lead to unintentional  injury such as a motor vehicle crash, fall, or poisoning. 

According to the CDC:  Synthetic cannabinoids (e.g., synthetic marijuana, K2, Spice,  Spike)—or plants sprayed with unknown chemicals—are dangerous and  unpredictable. Synthetic cannabinoids are not marijuana, but like THC,  they bind to the same cannabinoid receptors in the brain and other  organs.

Research shows that synthetic cannabinoids affect the brain much more  powerfully than marijuana creating unpredictable and, in some cases,  life-threatening effects including nausea, anxiety, paranoia, brain  swelling, seizures, hallucinations, aggression, heart palpitations, and  chest pains.

According to the CDC:   We do not yet know. Chemicals from marijuana can be passed to your baby  through breast milk. THC is stored in fat and is slowly released over  time, meaning that your baby could still be exposed even after you stop  using marijuana. However, data on the effects of marijuana exposure to  the infant or baby through breastfeeding are limited and conflicting. To  limit potential risk to the infant, breastfeeding mothers should reduce  or avoid marijuana use. 

A prescription cannabis product must be standardized, consistent and  display a quality equal to any New Chemical Entity that has passed  muster as a pharmaceutical (Russo, 2006a; Russo et al., 2015).  It must also possess a practical and suitable delivery system that  minimizes patient risk, including intoxication, other aspects of drug  abuse liability (DAL) or serious adverse events, such as pulmonary  sequelae. An additional requirement is a supply chain that ensures  security that it is being distributed to its intended target patients. 

Canadian medical marijuana activist Rick Simpson has been educating people about the incredible healing potential of cannabis oil. In 2003,  Simpson discovered three suspicious spots on his face and neck and was  diagnosed with basal cell carcinoma skin cancer.  When surgery didn’t work, he decided to explore an alternate route;  using the same extracted cannabis oil he’d been making and taking orally  for over a year on his newly discovered cancer.

Simpson had been treating some health conditions from a previous  injury with his cannabis oil when he recalled a study published in the  Journal of the National Cancer Institute stating that THC was found to kill cancer in mice.  So, Simpson proceeded to apply the oil topically to the cancerous spots  on his neck and face and covered them with bandages. In just four days,  the skin underneath was healthy and pink.  

According to Drugs.com:  It is impossible for anyone to accurately state the time it would  take for somebody to test clean. This is because there are many  different variables that impact on the rate that marijuana is both  metabolized and excreted (see below).

An estimate of marijuana detection time after last usage is as follows:

• One time only: 4-8 days
• 2-4 times per month: 11-18 days
• 2-4 times per week: 23-35 days
• 5-6 times per week: 33-48 days
• Daily usage: 49-70 days after last use*
  *Occasionally, some chronic users with a high tolerance may eliminate THC as fast as a one-time user.

We can give an estimate of the time, but the most reliable way is to  test yourself twice weekly until your first, morning urine sample tests  clean. However, even this is not 100% foolproof because home drug  detection kits have a higher upper limit of detection (usually 50 ng/mL)  compared to some other medical testing kits. This means you may test  negative, but a laboratory test may still show marijuana in your system.

Note that charts, graphs, or computer programs that claim to be able  to predict how long it will take you to test drug-free, are essentially  useless at doing this, even though they may say otherwise.

According to Drugs.com:  Marijuana is produced by the cannabis sativa plant. Cannabis sativa  contains over 421 chemicals including 61 different cannabinoids, of  which delta 9-tetrahydrocannabinol (delta-9 THC) is considered the most  psychoactive. Delta-9 THC has a thick, sticky consistency (somewhere  between a solid and a liquid) and is easily vaporized. It readily  dissolves into lipids and fats, and once in the body gets deposited in  fat (adipose) tissue, and in the liver, lungs, and spleen.

Delta-9 THC undergoes metabolism in the liver to another psychoactive  compound, 11-OH-THC, and then further metabolism to the inactive  THCCOOH. CYP2C9 and CYP3A4 are major enzymes involved in this metabolism  and both enzymes show genetic variation – this means that some people  will metabolize THC faster than normal, whereas others will metabolize  it slower than normal.

According to Drugs.com:  Individual variables that play a role in how long marijuana stays in your system for and detection times include:

• Body fat: People with more body fat will retain THC for longer. Skinny users have fewer places to store THC.
• Fluid intake at the time of the test.
• Genetics: Fast metabolizers will excrete THC rapidly.
• How frequently you exercise.
• Method and frequency of usage: Infrequent users clear THC faster than chronic users.
• Type of detection test used (blood, hair, saliva, or urine).
• Your general health: Many medical conditions impact on how your body retains, stores, and metabolizes marijuana.
• Other drugs taken: Many drugs interact with CYP2C9 and CYP3A4 enzymes.
• The potency of the marijuana and your tolerance to it can also have an impact.

Firstly, it is important to understand the difference between qualitative and quantitative testing.

Qualitative testing tells you if a substance is there or not. It does  not tell you how much of the substance is there. There will be a cut  off point for detection. For example, the Alere DDs 2 Mobile test system  used roadside by law enforcement agencies has a cut off level for  Delta-9-THC in saliva of 25 ng/ml. Research has shown that this testing  system is 97.5% accurate at this cut off (this means that more than 97  people will accurately test positive out of 100 people who have used  marijuana in the past 24 hours).

Quantitative testing measures the actual quantity of a substance.  This type of testing is more expensive and time-consuming than  qualitative tests and is normally reserved for people who have tested  positive in a qualitative test. It needs to be done in a laboratory and  is used when a more defined value is needed, say, for prosecution.  Quantitative testing can detect minute quantities of a substance, far  below the cut off point in a qualitative test. A series of quantitative  tests can determine if drug usage is ongoing or has stopped.

The most common ways marijuana can be tested for is in urine, saliva,  blood, or hair. Most testing practices look for the presence of THCCOOH  which has a much longer half-life (the time it takes for 50% of the  substance to be excreted) than delta-9 THC. The half-life of THCCOOH is  20-57 hours in occasional users compared to 3-13 days in regular users.

 A false-negative is when the test result is negative for a substance,  but the person has been using the substance. A false-positive is when  the test result is positive for a substance, but the person hasn’t been  using the substance. 

For kits that detect at the 50 ng/ml level the circumstances would have  to be extreme, for example, if you were in a closed car full of  marijuana smokers for a couple of hours and you were drug tested the  next day. If you are a non-smoker in a ventilated area where other  people are smoking marijuana you are generally safe.