Can I Use Cannabis Before and After Surgery?
Marijuana and health are becoming more and more intermixed as time goes on. People are beginning to realize the physical and mental benefits medical marijuana can offer in day to day life and have started using it to help themselves in ways traditional pharmaceuticals have been previously unsuccessful. However, for those with chronic conditions that require the use of other drugs or surgeries, it is vital to be aware of the potential interactions or effects caused by marijuana. In this post, we will look into if marijuana is safe to use before or after surgery.
Marijuana and Other Drugs
When ingested, marijuana undergoes quite a bit of changes in the body. Edibles, for example, pass through the digestive tract before being absorbed, resulting in many important changes to the chemistry. Similarly, when other drugs pass through the body, they are changed themselves. This is vital to the science of pharmaceuticals. After all, what good is a drug that is active outside the body but changes to an inactive form when ingested?
In marijuana’s case, there are many different forms and methods that are all changed in different ways. Whether it is through inhalation, sublingual application, or ingestion, there are many possible places marijuana can interact with other drugs. Notably, these drug interactions can have many different results, and may not just add together or cancel each other out. As a general example, marijuana may interact with any drugs that are processed within the liver, these include acetaminophen, alcohol, and, importantly, anesthetics.
There is an effect in drug metabolism known as the “first pass effect”. The first pass effect occurs when a drug’s concentration is lowered before reaching the bloodstream. Essentially, it means that if you take 100mg of a drug, it doesn’t necessarily mean that 100mg ends up circulating around your body. Certain methods of application bypass first pass metabolism, including the previously mentioned inhalation and sublingual methods. In such cases, it may be interesting to compare the oral and sublingual doses, as in most cases, the sublingual form will have a much lower concentration with drugs susceptible to the first pass effect.
Marijuana Use Before Surgery
The interactions we have looked at up until now have all occurred when the drugs are introduced concurrently, but what about hours, days, or weeks later? In these cases, there may not be any immediate drug-on-drug interactions, but long-term use of marijuana can change the way pharmaceuticals react in the body.
Specifically, regarding surgery, it was found that marijuana use resulted in both airway obstruction and an increase in anesthetic doses needed . This correlates with previous findings regarding marijuana use and surgical outcomes. Furthermore, it was found that marijuana smoke was correlated with both airway inflammation and increased risk of respiratory illness .
Another thing to consider is the effect of marijuana on the heart and vascular system. Some studies have shown that marijuana use can have adverse effects on the heart over time. In the short-term, marijuana has been shown to both increase heart rate and lower blood pressure. For those with hypertension, this can be beneficial in some cases. Before surgery, however, this can cause problems both with anesthesia dosage and the physical aspect of the surgery as well.
These findings have come to light in the real world as well. Physicians in Colorado have started to come forward by describing their issues caused by legalized marijuana. Due to the length of time marijuana has been legal in Colorado, its use is very high across the state. Because of this, surgeons and anesthesiologists must be very aware of the physical effects caused by marijuana, along with the previously mentioned drug interactions. These doctors have also made note of the increased tolerance of marijuana smokers in regard to common anesthetics, citing possible side effects due to their higher doses including even lower blood pressure and lessened cardiac efficiency.
Marijuana After Surgery
The effects of marijuana after surgery are even less researched than its effects beforehand. In some cases it seems to be beneficial, while in others it can cause problems. For example, those who have had surgery near the abdomen are recommended to stay away from smoking marijuana due to the risk of cough which could cause further damage to the area. Some people, though, have had some success with using marijuana as a pain or inflammation reducer after surgery. In these cases, marijuana can offer some relief though it is highly recommended to speak with a physician before using it.
Overall, marijuana can have a variety of effects within the body, especially when combined with other drugs. These go beyond simple additive or subtractive effects and can include dizziness, nausea, and anxiety. During surgery specifically, marijuana can react with many common anesthetics, raise the necessary amount of anesthetic for surgery, and lower blood pressure. All of these can cause problems for both the physician and the patient. Post-surgery, marijuana may cause problems in certain cases, or raise the risk of injury due to misuse, but may also provide relief to some users. In all cases, it is vital to speak with a physician honestly regarding marijuana use both before and after surgery, including both past and present use.Can I Use Cannabis Before and After Surgery? Marijuana and health are becoming more and more intermixed as time goes on. People are beginning to realize the physical and mental benefits medical
Is Smoking Cannabis Before or After Surgery Safe?
Most would agree that preparing for surgery is an anxiety-laden task, and with fair reason—whether elective or not, surgery is a serious matter. For the cannabis lover, it may seem obvious to turn to a toke to soothe the nerves in preparation for the big event, but is it wise to do so? Are there any contraindications to smoking before surgery? How about smoking after surgery, and does cannabis make a good post-op medicine?
To find out, Leafly reached out to Dr. David Bearman, a leader in cannabinoid medicine with a long career in drug abuse treatment and prevention, as well as author of the book Drugs Are Not The Devil’s Tools. Dr. Bearman’s credentials are extensive, ranging from his time serving the U.S. Public Health Service, to co-founding the American Academy of Cannabinoid Medicine, and much more.
The top question on the list: Is it safe to consume cannabis before a surgery? The answer, as one may expect, is not a simple yes or no, but instead relies on a few variables.
Note: Although Dr. Bearman is providing his expert opinion, as with all medical concerns, please consult with your doctor or surgeon about consuming cannabis before or after a surgical procedure. For more information, please refer to Leafly’s Terms of Service.
How long before surgery should one stop smoking cannabis, if necessary?
Bearman: The therapeutic and recreational effects of smoking cannabis usually last from 1.5 to 2.5 hours. For most surgeries, patients arrive at the hospital more than three hours prior to the surgery.
However, smoking can cause increased sputum production; for that reason, I would recommend not smoking cannabis for several hours prior to the surgery.
In terms of people who are using oral administration, the effects are going to last 3-6 hours. The night before surgery you are instructed not to eat anything after 10:00 p.m., so if you follow pre-op instructions, any effect from oral use would be gone well before the surgery.
There is some speculation that cannabis may affect the heart adversely. Are there any contraindications that heart patients should be aware of?
Bearman: I don’t want to glorify it by calling it a study, but a “study” was done on the East Coast a few years ago suggesting that people who smoke cannabis have an increased chance of having a heart attack. This was a retrospective study, never reproduced, and highly criticized, so I don’t think that I have seen any strong evidence that would suggest that cannabis has adverse cardiac effects.
The effects of cannabis on the heart are, how can I say, not very large and are variable. According to the 1999 Institute of Medicine report, the effects on blood pressure is that it may make it go up or down by five milligrams. That’s not an enormous amount; it’s basically the same as saying it doesn’t have much effect.
Now what I’ve noticed in a very small number of patients who have severe hypertension, is that cannabis can be amazingly successful in lowering their blood pressure to the normal range. I think that for people who have severe hypertension, I would suggest avoiding cannabis use before surgery, just because we don’t know what the effects of it are going to be. It’s possible that they might actually end up with hypotension—the combination of the cannabis and the anti-hypertension medication might be confusing to the anesthesiologist, who needs to know all the medications they’re on.
It’s very important that if a person is regularly using cannabis that they make sure they let the anesthesiologist know, so the anesthesiologist is aware of all of the medications they’re taking, including cannabis.
Now, in addition, there is supposed to be a fleeting effect [by cannabis] on pulse; it may cause it to increase. Frankly, I don’t know how fleeting it is, but I’ve seen thousands of patients and I don’t think the pulse rate of my patients is any more abnormal or higher than the average patient. So, I don’t think it’s a big deal, because it’s unlikely [your doctors] are going to let you smoke marijuana a half hour before your surgery.
What’s the best method of consumption before surgery?
Bearman: As mentioned, when cannabis is smoked it does cause an increase in cough and an increase in sputum production, so it’s probably not a great idea to smoke it prior to a surgery. If a patient is going to use it before surgery they’re going to want to choose a method other than smoking. Since vaporizing has 70% [fewer] irritants than smoking, if a patient wants to use the respiratory method, they should vaporize.
Alternatively, a patient may want to use an oral administration such as a tincture or edibles.
Is cannabis a beneficial choice as a post-op medicine?
Bearman: Yes, I think using it post-op is fine. Again, I wouldn’t smoke it. Particularly after abdominal surgery—that would be a contraindication. With abdominal surgery, doctors don’t want to see you coughing or vomiting. When a surgeon cuts into a person’s abdominal, sutures everything up, and then they start coughing or they start vomiting, the sutures start to come undone because of an increase in the inner abdominal pressure.
So, I would certainly think that cannabis is very useful for treating pain post-operatively, but in particular with abdominal surgery I wouldn’t smoke because of the possibility of coughing. If a patient wants to use the respiratory route they may want to try vaporizing, or it may be more prudent to use an under-the-tongue spray or other routes of oral administration.
Interestingly enough, historically if you go back to the 19th century, and certainly before that, cannabis was used as a childbirth anesthetic. One of the things we know about the cannabinoids is that many of them have analgesic properties, and THC has the most. It may decrease the dosage of pain medication that the person requires post-operatively.Leafly asked Dr. David Bearman, a leader in cannabinoid medicine, if it’s safe to smoke or consume cannabis before and after a surgical procedure. ]]>