asthma and cannabis


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Asthma: How should cannabis or THC be taken to treat asthma?

British Medical Association

Acute doses of cannabis and THC exert a definitive bronchodilator effect on the small airways of the lungs. The mechanism of this effect is not known, but it appears to be different from that of other drugs used at present as bronchodilators for asthma. (…) However, there have been very few studies on the bronchodilator effects of cannabinoids in asthmatic patients. All of these were studies carried out in the 1970s. Tashkin et al. studied 14 asthmatic volunteers and compared smoked cannabis (2%THC), oral THC (15mg) and the drug isoprenaline (0.5%). They found that smoked cannabis and oral THC produced significant bronchodilatation of at least two hours duration. The effect of smoked cannabis was nearly equivalent to the clinical dose of isoprenaline. Smoked cannabis was also capable of reversing experimentally induced bronchospasm in three asthmatic subjects. (…) Williams et al. compared a THC aerosol containing 0.2 mg THC with a salbutamol aerosol (0.1 mg) in 10 asthmatic subjects. Both drugs significantly improved respiratory function. The onset of effect was more rapid with salbutamol, but the effects of both drugs were equivalent at one hour. Tashkin et al. compared several doses of THC aerosol (5-20mg) with a standard dose of isoprenaline in 11 normal volunteers and five asthmatic subjects. In the normal subjects and three of the asthmatics, the bronchodilator effect of THC was less than that of isoprenaline after five minutes, but significantly greater after one to three hours.
(Please note: This text has been taken from a scientific article. Some sentences have been changed to improve understandability.)
British Medical Association: Therapeutic Uses of Cannabis. Amsterdam: Harwood Academic Publishers, 1997.

Franjo Grotenhermen

The treatment of asthma includes the use of anti-inflammatory drugs (corticosteroids) and bronchodilators. THC and cannabis are bronchodilators and may also exert some anti-inflammatory and anti-allergic action. Cannabis smoke contains combustion products qualitatively similar to those found in tobacco smoke, among them several carcinogens that may damage the mucosa. The inhalation of these combustion products should be avoided or strongly decreased. To avoid the intake of combustion products cannabis can be taken orally. To decrease the amount of inhaled carcinogens cannabis or THC can be inhaled by a vaporizer, and/or cannabis with a high THC content can be used/smoked. In several situations, a combination of a basic oral medication and a demand inhaled medication in acute asthma attacks may be useful to reduce the risks from smoking and the risk of overdosage with oral administration. The availability of a THC aerosol is desirable.

Calignano and colleagues

An international research group has discovered why marijuana causes coughing in some situations but may inhibit bronchospasm and cough in others. This finding could lead to better treatments of respiratory diseases. In a report in the journal Nature scientists from the Institute of Experimental Medicine in Budapest (Hungary), the University of Naples (Italy) and the University of Washington (USA) showed how the endocannabinoid anandamide influences the airways in the lungs. In animal studies with guinea pigs and rats, anandamide exerted a dual effect on bronchial responsiveness. If the muscles in the lungs were constricted by an irritant (capsaicin) the endocannabinoid relaxed the smooth muscles and strongly inhibited coughing. But if the airways were relaxed (by removing the constricting effect of the vagus nerve) anandamide caused a coughing spasm. Anandamide is synthesized in lung tissues and its effects are mediated by cannabinoid receptors. (…)
IACM-Bulletin of 12 November 2000; Calignano A, et al: Bidirectional control by airway responsiveness by endogenous cannabinoids. Nature 2000;408:96-101.

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Journals You are here: Home > FAQ > Asthma: How should cannabis or THC be taken to treat asthma? Asthma: How should cannabis or THC be taken to treat asthma? British Medical Association

Can You Treat Asthma with Cannabis?

Asthma is a chronic health condition that affects the respiratory system. Asthma has been on the rise since the 1980s, and over 25 million people in the United States alone currently have asthma. Asthma causes a number of respiratory issues, including episodes of severe difficulty breathing, which can be fatal. There is no cure for asthma, but when properly managed, its effects can be dramatically reduced. In their search for effective asthma treatments, researchers have discovered a positive link between cannabis use and improvements in asthma symptoms.

Marijuana and asthma

Since asthma is often attributed to inhalation of smoke or other pollutants, it seems logical that marijuana use would worsen or cause asthma. Surprisingly enough, many asthma patients have found the benefits of cannabis to outweigh the potential drawbacks of exposure to its smoke.

What causes asthma?

People with asthma experience inflammation and constriction of the airways between the mouth and nose and the lungs (bronchospasm). This effect can range from mildly irritating to very severe. Well-controlled asthma may present few symptoms at all. At the other end of the spectrum is a condition called asthma exacerbation (better known as an “asthma attack”). During an asthma attack, the airways become so inflamed and constricted that breathing becomes extremely difficult. Asthma attacks can be life-threatening.

Some people suffer frequent attacks, others very rarely. The likelihood of having an asthma attack increases in response to viral infections (including the common cold), exercise, laughing, crying, emotional stress, hyperventilation, cold temperatures, or irritating substances in the air (including smoke). Asthma attacks are typically worse first thing in the morning or at night.

The exact cause of asthma is still unknown and even appears to vary from person to person. Asthma is considered to be an auto-immune condition – where the immune system overreacts to potentially dangerous substances and ends up damaging the body in the process. In most cases, asthma develops as an allergic reaction. Asthma can be aggravated by specific airborne substances, such as secondhand smoke, pollutants like construction dust, pet dander, dust mites, or auto exhaust. Asthma frequently develops in childhood, and the risk is higher for children who experience recurrent viral respiratory infections. Exposure to certain airborne microbes may also contribute to the development of asthma, although other microbes appear to offer some protection against it. There is still much more research needed to fully understand asthma and what causes it.

How weed can help asthma

Research suggests that in many cases, yes, weed can help asthma. Marijuana has powerful anti-inflammatory properties, and inflammation directly contributes to bronchospasm. In the 1920s, physicians were well-aware of weed’s therapeutic effects and used to prescribe it as a cough treatment for asthma sufferers. Research has shown that people (with or without asthma) who smoke weed develop a higher lung capacity than those who do not. However, chronic heavy use of smoked marijuana may have the opposite effect.

The best way to treat asthma with weed

In most cases, vaporizing or “vaping” weed is the best delivery method to relieve an asthma attack. Smoking and vaping weed both go to work immediately, helping to relax and open the constricted airways. Because you are inhaling vapor instead of smoke, vaping is easier on the lungs. Some people do find effective asthma relief from smoking weed and feel that the benefits outweigh any irritation. However, if vaporizing is an option, it’s likely the better of the two. Edible marijuana does hold potential as a long-term asthma treatment. But if you are in the midst of an attack, edibles won’t help much since they take much longer to kick in.

Whether you smoke or vape cannabis to alleviate your asthma, you may experience a dry throat and/or coughing. Keep water on hand to help manage these potential side effects. Opting for calming strains of weed may also help to soothe the panicked feeling that naturally accompanies being unable to breathe.

Q: Does weed help asthma?
A: It does appear that weed can aid in the management of asthma symptoms, though more research is needed to discern the most effective and lowest-risk ways to do this.

The risks of using weed with asthma

The marijuana plant itself doesn’t appear to have an adverse effect on asthma unless you are allergic to it. However, smoking marijuana (or inhaling secondhand marijuana smoke) does have the potential to cause problems. Smoking weed ups your chances of developing lung cancer, and the smoke may aggravate asthma symptoms in many people, If your asthma symptoms appear to get worse when using cannabis, the potential benefits are probably not worth the risks, and you should discontinue use.

Q: Is weed bad for asthma?
A: As long as you are not allergic to cannabis, there is no evidence that marijuana on its own is bad for asthma. Smoking weed (or inhaling secondhand smoke) may contribute to asthma symptoms, but it appears to be the smoke itself that is the irritant – not the cannabis.

Smoking weed with asthma – is it good or bad?

Smoking weed when you have asthma tends to seem paradoxical. Any exposure to smoke has the potential to damage the lungs and aggravate asthma symptoms. Despite this, there are cases where the benefits gained from smoking cannabis are worth the risk.

How marijuana smoke affects asthma

If you have asthma and smoke weed, you may experience higher incidences of coughing, excessive build-up of phlegm, wheezing, shortness of breath, tightness in your chest, and you may be more susceptible to lung infections. The possibility does exist that irritation from smoking marijuana could prompt a life-threatening asthma attack. This risk is due to the irritation caused by smoke inhalation, not specifically because the smoke comes from cannabis.

Marijuana is usually smoked unfiltered and held in the lungs longer than cigarette smoke. This means that a significant amount of tar and toxins end up in the lungs. Smoke and other toxins can damage the lining of the airways and cause them to become inflamed. Heavy marijuana smoking has been linked to an increased risk of lung damage, lung cancer, bronchitis, and COPD (chronic obstructive pulmonary disease). Smoke combustion releases toxins and is bad for the lungs whether it comes from weed, cigarettes, or campfires. Being a marijuana smoker may also render you ineligible to receive a lung transplant, should your lung damage ever progress to that point.

Q: What happens if you smoke weed and have asthma?
A: It is possible that asthma symptoms such as coughing, wheezing, and shortness of breath will worsen if you smoke weed. However, smoking cannabis gives many people near-instant relief from bronchoconstriction, which can stop an asthma attack in its tracks.

Smoke combustion releases toxins and is bad for the lungs whether it comes from weed, cigarettes, or campfires.

Secondhand marijuana smoke and asthma

There have been documented cases of asthma symptoms being caused by cannabis allergy. If you are allergic to cannabis, it’s highly likely that exposure to plant particles or marijuana smoke in the air will induce asthma symptoms or attacks. Even if you are not allergic to weed, secondhand marijuana smoke is highly irritating to the lungs and could exacerbate asthma symptoms.

Vaping weed with asthma

Vaping cannabis could contribute to throat irritation and/or coughing, but overall, it appears more beneficial than harmful for those with asthma. Since the plant matter or cannabis oil is heated up but not combusted, vaping allows you to avoid inhaling all of the toxins and tar that you do when you smoke. If you have asthma and are new to vaping, it’s recommended that you start out with your vaporizer at a low-temperature setting. Opt for the best quality vaporizer you can get. A good filtration system and the ability to pull consistent hits are especially important when you are vaporizing weed to treat asthma.

Medical marijuana for asthma

Medical marijuana prescriptions for the treatment of asthma are not available at this time, though this could change as more research on cannabis and asthma is done. In California, Oklahoma and West Virginia, physicians do have the authority to write prescriptions for any medical condition they deem appropriate, and there are a growing number of states where marijuana may be purchased and used for recreational purposes.

Medical marijuana prescriptions for the treatment of asthma are not available at this time.

CBD and asthma

CBD (cannabidiol) is a non-psychoactive chemical found in weed that shows promise as a treatment for asthma. CBD is an anti-inflammatory and helps by dilating and opening up the airways. CBD is also an antispasmodic. During an asthma attack, the smooth muscles in the lungs and bronchioles contract and constrict, narrowing the air passages. CBD can help these muscles to relax, giving you more room to breathe, literally. Hemp-derived CBD cannot get you high and is legal in all 50 U.S. states, even those where cannabis is not. CBD is considered safe for use by children and even pets.

Treating asthma with CBD oil

CBD oil can be taken orally or vaporized. Taking a few drops of CBD oil under the tongue may be an effective way to administer it during an asthma attack. Smoking or vaporizing is still the fastest-acting option, but if you find it too irritating or it makes your symptoms worse, then CBD oil taken orally may be the next best thing.

CBD asthma inhaler – an exciting new treatment

A couple of companies are working to get CBD inhalers into the United States and Canadian markets. In the meantime, many people have chosen to substitute their medically prescribed asthma inhalers with vaporized CBD. This option does allow you to avoid chemicals used in medically prescribed inhalers such as corticosteroids, which can cause side effects including anxiety, depression and increased blood pressure. However, this may not work for all people and we do not recommend stopping any prescribed medication without first consulting your physician.

CBD Asthma Inhaler

THC and asthma

THC (tetrahydrocannabinol), the chemical in weed famous for getting you high, also dilates and opens up the airways, which may be able to reduce or inhibit coughing attacks. This effect usually lasts about an hour. THC has also been shown to help suppress the immune system, which could help counteract the auto-immune response that is believed to be a cause of asthma.

Does smoking weed cause asthma?

If you are allergic to cannabis, exposure to it could cause you to develop asthma. In those who are not allergic, it does not appear that weed causes asthma. However, smoking weed (or inhaling secondhand marijuana smoke) could potentially aggravate symptoms and prompt asthma attacks. There are a few other respiratory conditions that have similar symptoms to asthma that are also worsened by exposure to marijuana smoke.

Marijuana smokers (particularly those under age 45, though researchers don’t yet know why) are more likely to develop a life-threatening condition called bullae, in which large air sacs form in the lungs. This condition can cause shortness of breath and, if the sacs rupture, air leaking into the lung can cause it to collapse (a condition known as pneumothorax). Marijuana smokers can also contract lung infections from aspergillus, a mold that lives on the cannabis plant. This mold can cause pneumonia, which can be fatal.

Q: Can smoking weed cause asthma?
A: Unless you are allergic to cannabis, it does not appear that marijuana causes asthma. However, exposure to marijuana smoke does have the potential to exacerbate asthma symptoms, up to and including asthma attack, whether you are allergic to cannabis or not.

Could cannabis be the asthma treatment for you?

The potential drawbacks and risk factors of smoke inhalation do make treating asthma with cannabis a complex issue. However, there is a strong link between cannabis use and the improvement of asthma symptoms. It is likely that as more research is done, the medical marijuana community will figure out how to put cannabis’ positive effects on asthma to work.

Q: Can people with asthma smoke weed?
A: If you have asthma but are not allergic to weed, you may be able to tolerate smoking it. However, vaporizing is typically a more comfortable option for asthma patients who use cannabis.

Q: Does smoking weed affect asthma?
A: Smoking weed may aggravate asthma symptoms, including inducing asthma attacks. Cannabis has also been shown to reduce inflammation and relax the bronchial muscles, helping to open up constricted air passageways during an asthma attack.

Q: Can you get medical marijuana for asthma?
A: Asthma is not currently a qualifying condition for prescribed medical marijuana.

Marijuana shows potential as an unexpectedly effective treatment for asthma.