Medical marijuana


Cannabis, a plant also known as marijuana, is commonly known for its recreational use. Because of the impact it has on human behavior, its use is banned in the United States. But marijuana has chemicals, called “cannabinoids,” that have shown promise in helping ease breast cancer treatment side effects such as nausea, vomiting, appetite loss and pain.


What is medical marijuana?

Medical marijuana is a phrase used to describe the use of the cannabis plant, either the whole plant or its chemical extracts, to treat symptoms of certain medical conditions or treatment side effects. The marijuana plant contains cannabinoids, unique chemicals that have been found to have medical benefits such as relieving pain, nausea and loss of appetite that may be side effects of breast cancer treatment.

Delta-9-tetrahydrocannabinol, commonly called THC, is the cannabinoid that has shown the most success in side effect treatment. But it is also the chemical that produces the intoxicating effect that draws people who use marijuana for recreation. Another cannabinoid, called cannabidiol or CBD, has also shown some health benefits without making you feel intoxicated, or “high.” Producers have bred marijuana plants that have higher levels of either THC or CBD to achieve certain effects, but there may be added benefits when both are present in the plant.

Scientists have been able to extract or replicate cannabinoids to get a specific effect in a pill or liquid form. Two medicines based on THC, dronabinol (Marinol) and nabilone (Cesamet), are currently U.S. Food and Drug Administration approved to treat nausea caused by breast cancer treatment.


How medical marijuana is taken

There are several ways to take medical marijuana, including many of the same methods used to take marijuana recreationally. The FDA has approved two man-made versions of THC, dronabinol (Marinol) and nabilone (Cesamet), to treat nausea, vomiting and appetite loss caused by cancer treatments, after other medicines have failed to control those side effects. THC is an active chemical in marijuana that has shown health benefits but also has side effects such as lightheadedness, dizziness, trouble concentrating and feeling high — effects that are also present in these man-made pills.

Dronabinol and nabilone are treated the same as other medicines: they can be prescribed by your doctor and may be covered by private insurance and government programs like Medicare and Medicaid.

  • Dronabinol: a man-made version of THC available as a pill or liquid taken by mouth. It is approved to treat nausea, vomiting and loss of appetite. During a chemotherapy cycle you may take four to six doses in a day for nausea, one every 2 to 4 hours. A first dose is taken an hour or more before getting treatment. For appetite, two doses a day is recommended, one each before lunch and dinner.
  • Nabilone: a man-made version of THC available as a pill taken two to three times a day for nausea during treatment with chemotherapy. A first dose is taken 1 to 3 hours before chemotherapy and it may be continued for 48 hours after chemotherapy.

Federal law still prohibits other ways people take or use medical marijuana, including any methods that burn or heat the dried marijuana plant to inhale smoke or vapor. These methods also are not FDA approved for use in side effect management.

But many states permit people with medical conditions such as breast cancer to buy and use medical marijuana in some or all of these forms:

  • Smoking, which involves burning marijuana in a rolled cigarette, a glass pipe, a water pipe (a pipe where the smoke is passed through water before being inhaled) or other device, and inhaling the smoke.
  • Edibles, food items, usually baked goods, made with medical marijuana that deliver its effects when eaten.
  • Vaporizers, which heat the marijuana leaf or an oil extract without burning it. The result is a vapor that can be inhaled.
  • Herbal tea, made by steeping marijuana or a marijuana-derived product in hot water with tea leaves.
  • Tinctures and other liquids applied under the tongue. Nabiximols (Sativex) is a THC spray for under the tongue approved for use in Canada and the United Kingdom but not the U.S.
  • Topical creams or gels applied to the skin.
  • Patches that deliver medical marijuana through the skin.

Each method comes with its own pros and cons:

  • With a cigarette or pipe, much of the smoke dissipates when you are not breathing it in. Smoking can also be hard for people with lung problems. When marijuana is smoked, you feel its effects very quickly.
  • Vaporizing comes with the same benefits as smoking and affects the lungs less, but the machines can be expensive.
  • Edibles and pills can be difficult to take when you are experiencing nausea. They can also take longer to go into effect. Edibles may be easier on your lungs, allow you to control the dose more carefully, and can be used more privately than smoking.

You may ask workers at the dispensary, where you’ll go to buy medical marijuana, which method might be best for you and the side effect you’re experiencing. Some states require dispensaries to have a qualified health professional on staff. Even if your state doesn’t, workers at dispensaries are knowledgeable and can help you choose a method and tell you how to take it properly. Remember that each state approves its use differently. They control which health conditions qualify for medical marijuana in your state, in what forms you can buy it, and how you get approved to use it. Cancer is among the conditions permitted in most states.

Dosing for medical marijuana is less regulated than with most medicines. The right dose can be very different from person to person. The common advice is to start with a small amount at first and then try more if your symptoms or side effects don’t get better, increasing the amount a little at a time. If you are not getting relief, ask about other ways to take medical marijuana or marijuana with different levels of THC and CBD.

No matter what you choose, you should always speak with your doctors about any new activity or substance that may affect your treatment.


How medical marijuana works

Your body makes chemicals similar to those found in marijuana. These chemicals made in your body are called endocannabinoids, and there are special receptors for them in your brain and throughout your body. THC, the most active chemical in medical marijuana, binds to these receptors, which eases pain and nausea.


Who gets medical marijuana?

Medical marijuana may be suggested to people who are having an especially difficult time with treatment side effects that don’t get better with other medicines or management techniques.

Because of the impact marijuana has on human behavior, it has been illegal in the United States since the early 20th century. States have recently started changing their laws to allow people with conditions such as breast cancer to use marijuana for medical purposes.

As of 2018, there are 29 states that have passed laws permitting medical marijuana. A further 17 have loosened their laws somewhat (some permit only marijuana that is high in CBD and low in THC, and others allow people in court for marijuana possession to claim a medical condition as a defense). Some states, such as Colorado and Washington, have legalized marijuana even for recreational use. But in others, such as Pennsylvania, where some forms of medical marijuana are allowed, you are not allowed to buy or use the marijuana plant — used in smoking, vaporizing and some edibles.

The National Conference of State Legislatures keeps a list of which states allow medical marijuana use. Even if your state is on the list, there are likely additional steps you must take to use it legally, such as having a doctor certify your condition and registering with the state. Each state has its own rules about what medical marijuana products are allowed and the steps you must take to get and use it legally.


Insurance coverage

Neither government health programs, such as Medicaid and Medicare, nor private health insurance cover medical marijuana.


Side effects

Like any medicine, medical marijuana can come with some side effects, including:

  • rapid heart beat
  • low blood pressure
  • bloodshot eyes
  • muscle relaxation
  • slowed digestion
  • dizziness
  • depression
  • paranoia
  • hallucinations

Smoked marijuana may have some of the same effects on the lungs as smoking tobacco. Stopping marijuana use may cause sleeplessness, irritability and hot flashes. Marijuana is less addictive than many prescription medicines and has a much lower risk of overdose.


Medical marijuana & federal law

Many states have changed their laws to allow people to use marijuana for certain medical conditions or treatment side effects. But the federal government still considers marijuana a “Schedule 1” substance. This category is used to strictly control substances with a high risk for abuse and no currently accepted medical use. This category puts strong restrictions on who can legally grow, buy or use marijuana whether for recreation, treatment or research. These federal restrictions conflict with the laws of individual states. This disagreement between state and federal law can make it difficult to know what is allowed.

The federal government has not enforced its restrictions against people who obey their state’s laws, but does restrict researchers seeking to learn more about its possible uses in breast cancer treatment. There is much to learn about the effects of medical marijuana and how it can be used to help people with medical conditions, but the schedule 1 classification makes research more difficult. The status comes with strict rules for using marijuana in a study and makes it harder to get the funding needed to hold clinical trials.

If you are considering medical marijuana to help ease breast cancer treatment side effects, check your state’s laws about its use and speak with your doctor about if it would be right for you.

The difference between state and federal policy on marijuana makes it hard to predict the future of any medical marijuana program. Doctors cannot prescribe medical marijuana because of federal law. Because of this, they can only tell you their opinion on whether it might work for you — but they can’t tell you to take it. It’s also possible that your doctors may not bring up medical marijuana, so you may have to start the conversation if you’re interested.

Because doctors can’t give you a prescription for medical marijuana as they would with other medicines, many states require instead that a doctor certify that you have a condition that qualifies for medical marijuana use. How they certify depends on the state. Your state may require a written letter from your doctor or that he or she fill out an online form. In some states, the doctor must also register in order to issue medical marijuana eligibility. If your doctor is not registered, he or she may be able to refer you to someone who is.


Medical marijuana states

The National Conference of State Legislatures has four requirements to say a state has a comprehensive medical marijuana program. The state must have laws that

  • protect you from criminal prosecution
  • provide a system to buy medical marijuana legally (such as dispensaries)
  • allow medical marijuana beyond just low-THC strands
  • allow some form of inhalation (through smoking or vaporizing the plant or an extract)

As of March 2018, there are 29 states plus Puerto Rico, Guam and Washington D.C. that have medical marijuana laws that meet the four standards set out by the NCSL:

Another 17 states have some laws allowing medical marijuana but not a “comprehensive program” according to the NCSL. Some allow medical marijuana that is bred to have lower amounts of THC, usually with higher amounts of CBD (CBD has been shown effective in treating some conditions, such as seizures, but may not be as effective at treating breast cancer treatment side effects). Other states allow people arrested for marijuana use to claim medical need as a defense in court, but do not have a system to allow you to use marijuana legally.

These states are:

No matter what, obey all local laws and do not travel with medical marijuana to avoid carrying it into a state or locality that bans it.


Medical marijuana & the workplace

You can be legally comfortable using medical marijuana so long as you obey the rules of your state and you are listening to the advice of your doctor. But be aware that there are some other impacts outside the law, like your workplace. If you are working, check your employer’s policy on medical marijuana use. A few states protect employees taking medical marijuana, so you may be able to request a reasonable accommodation in those places. Reasonable accommodations are small changes made in your job, workplace or schedule to help you work more comfortably while living with a medical condition or its side effects. These are supported by the Americans With Disabilities Act, or ADA.

In most states it is up to your employer to determine their policy on marijuana use. Some types of jobs may not allow its use at all. For example, you may not be protected if you work for the federal government, or if there is a safety concern, such as jobs that require driving or operating heavy machinery.


Reviewed and updated: April 17, 2018

Reviewed by: Judy Spahr MLS, MEd, CCRC, CCRP


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Living Beyond Breast Cancer is a national nonprofit organization that seeks to create a world that understands there is more than one way to have breast cancer. To fulfill its mission of providing trusted information and a community of support to those impacted by the disease, Living Beyond Breast Cancer offers on-demand emotional, practical, and evidence-based content. For over 30 years, the organization has remained committed to creating a culture of acceptance — where sharing the diversity of the lived experience of breast cancer fosters self-advocacy and hope. For more information, learn more about our programs and services.