Medicinal Cannabis

Cannabis Use, Cautions, Contraindications


Marijuana is remarkably safe to use. To date, there are no known fatalities. A lethal dose would be 20,000 to 40,000 times higher than a normal dose: consumption cannot induce a fatal overdose. However, as with any medication, it may not be harmless in some who have an increased risk such as pregnant or nursing mothers, adolescents, and persons with a family history of mental illness.

In particular, before deciding if the use of cannabis is safe, you should consult with your physician and review the potential for risk if you have the following conditions: pulmonary disease such as COPD, Hepatitis C, heart disease, stroke or hypertension.

Many new users have no effect the first time, and need to use cannabis a few times before they feel anything, as though their system needs to be primed. Carl Sagan anonymously wrote: “My initial experiences were entirely disappointing; there was no effect at all, and I began to entertain a variety of hypotheses about cannabis being a placebo which worked by expectation and hyperventilation rather than by chemistry. After about five or six unsuccessful attempts, however, it happened.” He used cannabis from 1959 until his death in 1996.

Cannabis does have a “paradoxical” ability to produce precisely opposite reactions in different circumstances. It can relieve symptoms and at other times aggravate them in exceptional situations for exceptional persons.

In other words, it is filtered through your consciousness, and if you are conflicted or feeling concerned about its use, it may magnify those predilections. So plan to relax and try it in a pleasant atmosphere when you are not rushed. Some never feel adverse side effects from cannabis, others say it depends upon the blend they use, and others may develop tolerance to the side effects with repeat use.


I. Blood Pressure

Cannabis may drop blood pressure by as much as 40 points.

A severe drop like that is probably rare and was possibly related to anxiety in a first time user. However it occurred in a patient who has high swings in pressure.

According to one protocol that tested it for postoperative pain, cannabis may lower blood pressure 10 or 20 points and increase heart rate as much as 50 to 60 points. This is dose related.

If your blood pressure is already as low as 100 or 105, it may drop your blood pressure too low for safe use.

Some users have found it may lower blood pressure on one occasion, and on another do the opposite [Marijuana Medical Handbook, Gieringer, Rosenthal, Carter, 2008, p. 112]

Marijuana is contraindicated in those with ischemic heart disease. Their blood pressure is already too low. We like to see blood pressure above 100 !

Therefore, check your blood pressure and pulse before and after use when you feel the medication has reached peak effect

whether used as a sublingual elixir or tincture, inhaling vapor or smoke, or swallowing candies, food and drink.

Blood pressure may not be an issue for a young adult, but may be serious for older persons because arteries lose elasticity as we age.

If pressure is too low, the brain and heart do not receive enough blood and oxygen which may lead to serious problems. Use wisely. It depends on the dose used.

Rapid heart rate may be worse when combined with other drugs that have anti-cholinergic effects such as the tricyclic antidepressants desipramine, amitriptyline, nortriptyline.

If you are concerned, a beta blocker can be used to limit the heart rate. Beta blockers also lower blood pressure.



II. Choosing a blend or hybrid to try

I recommend you read this post especially if you are immunosuppressed or wish to avoid side effects.

Ask the distributor to tell you how to determine if the bud has fungus or bacteria especially if you are immunosuppressed

which occurs in autoimmune disease, diabetes, HIV/AIDS. A few large distributors check with microscopes.

Buy organic, avoid growers who use pesticides.

Choose a blend or hybrid higher in Sativa for daytime use and higher in Indica for sleep.

Indica strains relieve symptoms but will also make you sleepy, some may cause severe sedation. Sativas are said to be energizing, focusing and inspirational.

Cannabidiol (CBD) and THC are two of the more important cannabinoids of the 86 cannabinoids so far discovered in the plant. THC is the main psychoactive ingredient in cannabis. If you can, try to find strains that are rich in cannabidiol (CBD). They may already be available in San Diego. Read more about CBD here.

CBD blocks the psychoactive effect of THC so you don’t feel “stoned,” lethargic or euphoric. You can then use a higher dose for relief if needed. CBD has valuable medical qualities in itself, works synergistically with THC, and is thought to have anti-psychotic effects. It is the main cannabinoid in hemp or ditchweed.

To learn more about these two important cannabinoids, THC and cannabidiol (CBD), I recommend that you watch the BBC documentary “Should I smoke dope?” Psychosis: THC & cannabidiol experiment. From that video you can see instant severe mood changes, paranoia, anxiety, panic that may occur with potent THC – not with CBD.

If you have disturbing side effects, try to relax. Use relaxation techniques. They will go away. If necessary, sleep it off. Next time, simply use less or try a different blend even though it may have no CBD. Not all will cause problems.

Some cannabis may be so strong you cannot stand up and walk. Another may cause severe sedation, useful for those with insomnia or those whose pain prevents restful sleep.

Try several blends until you learn what works for you. Work with your dispensary. Each plant may produce different moods.

It is a medicine, an herb. Be aware if it interacts with other prescription medication.

Cost: Eating cannabis requires four to eight times the amount of marijuana than that needed for smoking. And smoking causes combustion but vapor does not. Combustion means you are igniting a fire to a very expensive herb. Unless you grow your own, it can be very expensive depending upon your need.

Duration of relief may be much longer, six to eight hours, when the herb is used in tea, candies or baked goods compared to shorter effect from vapor or tincture. This may vary with choice of blend, potency, age of the herb, how dry or moist it is and conditions under which you store it.

Storage of the herb should be discussed with your dispensary. Ask them about the difference between a dry or moist bud. A fresh bud will be sticky from its natural oils. You don’t want to be wasting a large sum on old herb that has been sitting around decomposing for weeks. Cannabis is lipophilic meaning it dissolves in oil, not in water.

Hashish: Ask how they make the stronger form of cannabis called hashish. Hash is an assemblage of tiny resin glands removed form the cannabis plant. They are loaded with cannabinoids and terpinoids. Ask whether they use (deplorable) chemical solvents in the process. “Water processed hash will not be as flavorful as dry-sieved, since much of the aromatic oils are lost. But it is a simple, straightforward process….” according to the 2nd edition of “HASHISH!”by Robert Clarke published 2010. Clarke and others believe that “terpinoids (and possibly other aromatic compounds) account for the subtle psychoactive variations induced by different varieties. Aromatic compounds may also determine the increased efficacy of certain varieties for a particular medical indication.”

Terpenes are the odor molecules found in the essential oils of plants. Plants produce essential oils for various reasons, and each has characteristic odors. Aromas are used in aromatherapy to produce specific mood and medicinal benefits. The odor of various terpenes gives a clue about the medicinal quality of the plant. Once you find a hybrid that works well for you, you will be able to achieve the same benefit from others if they have the same or similar fragrance. Refer to Marijuana Medical Handbook, p. 217, for a description of the benefits from the seven terpenes in the cannabis plant.

You can read more about cannabis research and use from O’Shaunessy’s, the Journal of Cannabis in Clinical Practice. Your doctor or distributor may have a copy.

Check this post for patient experiences, benefits and side effects, and add your experience with use for the benefit of others. It may take work to find just the right blend for you.

Work closely with your experts to achieve the right blends of marijuana and the right balance with your blood pressure and underlying health conditions.

Finally, from an interview with Jeffrey Hergenrather, MD, president of the Society of Cannabis Clinicians:

Different strains contain different mixes of cannabinoids and terpenes that give them distinct qualities. Some strains energize you; others put you to sleep. Many patients, when they find a strain that suits their needs, try to obtain it on a regular basis. Unless they are growing their own from cuttings, however, they have to rely on growers and distributors to reproduce and make available the preferred strain from year to year.

Due to Prohibition, California growers have been denied the tools of analytical chemistry to test the cannabinoid contents of their plants. This has impeded the development of strains aimed at treating various conditions. Nevertheless, patients continue to educate themselves about cannabis as medicine and how best to use it.

Familiarize yourself with tinctures, elixirs, vaporizers, smoking, topical ointments and growing marijuana. News stories about one community may help you in yours. For example, Laguna Woods Retirees Form a Marijuana Collective because they have no access to this medication due to laws against marijuana pharmacies anywhere in their community. The archives along the lower right column show 40 posts in August 2009, so be sure to watch for Next Page » at the bottom of each long list of posts. There are many pages!


“We have potency down. Unfortunately potency does not equal character. A good comparison is the wine industry, where you have fortified wines and then you have fine Merlots. My advice is: focus on producing the fine bottle of Merlot.”  DJ Short, quoted from O’Shaunessy’s Summer 2010.


III. Benefits of vapor, smoke, tincture (under the tongue), ointments and swallowing (edibles, tea, candies)

For new users, I recommend trying a vaporizer and/or tincture under the tongue. Try topical ointments for arthritis or autoimmune rashes. A dispensary can order ointments  premixed with shea butter, coconut oil, and beeswax. Smoking, vapor or tinctures used under the tongue will be effective rapidly so you can gauge the effect. See recipes to make tinctures or elixirs. Cannabinoids can be administered by smoking, vaporizing, oral ingestion, transdermal patch, intravenous injection, sublingual absorption, or rectal suppository.

New users need to allow extra time and use a little caution until they feel comfortable with the dosages and the hybrid they purchased. Edibles are unpredictable.

Smoking vs Vaporizer: Smoking cannabis or using a water pipe introduces tar into the lungs; use of a vaporizer does not. It is a smokeless delivery system.

Vaporizers also eliminate toxic hydrocarbons toluene, benzene and napthalene that are present in smoke, and vaporizers reduce carbon monoxide.

When set to 312 degrees F, it vaporizes without smoke. Some say heat cannabis to a temperature of 170 – 200° C (356° – 392° F), just below the point of combustion where smoke is produced. At a higher temperature it may begin to scorch.

Edibles: Caution when swallowing cannabis in food, candies or drink. Cannabis that is swallowed goes through the liver where it is processed and becomes more psychoactive.

“The major drawback of ingesting marijuana is that the effective dose can be difficult to predict.

The effect is faster on an empty stomach. When cannabis is swallowed, it may take 30 to 120 minutes or longer to feel the effect and may reach a peak in 2 to 3 hours or even 6 hours in some cases.

Yes, cannabis suckers are swallowed. They are not absorbed under the tongue.

Cannabis is oil and fat soluble, it does not dissolve in water. It is best prepared in butter, oil, milk or alcohol.

When peak effect occurs six hours later, that may be too late for you to realize you have taken a dose that is acutely uncomfortable or you are not able to function the rest of the day. If you overdose on baked goods or candy you may potentially have hours of heart palpitations, low blood pressure, severe anxiety, panic, paranoia or uneasy mood changes lasting all day, even possibly psychosis and hallucinations if it had a very high percentage of THC and no CBD. You may be unable to walk. If blood pressure is low, you should avoid standing or you may faint. Remember every batch will be different unless your marijuana pharmacy has labeled the potency. Perhaps only one large dispensary in California does label potency, but few small pharmacies can afford to test.


IV. Legal

Keep up to date on legal regulations of San Diego County here and do read the ones posted on this site. Use the search function on this page at top.

Those and many other resources are on this website including points of law to observe – such as boarding a plane in California with medical marijuana which is a violation of federal law.

You may be able to board a plane in Oakland, but leaving the plane in another part of California may pose a problem you would wish to avoid.

  • It is not legal to drive while intoxicated.
  • It is not legal to share your medication with others.
  • It is not legal to smoke while operating any motor vehicle, on land or otherwise!
  • When transporting medicine, keep it in the trunk!!
  • If there is no trunk, keep the medicine out of sight and out of reach of the driver to prevent any suspicion of DUI
  • It is not legal to smoke or grow within 1000 ft of a school, daycare, or school bus stop.
  • It is not legal to buy or sell marijuana, even under state laws!!
  • To avoid the appearance of intent to sell, patients should keep their medicine in the original container.  Do not divide quantities!  The presence of scales, multiple packages of medicine, large amounts of cash may give police the evidence they need to charge someone with intent to distribute.



The material on this site is for informational purposes only, and

is not a substitute for medical advice, diagnosis or treatment provided by a qualified health care provider.~



1 Comment »

  1. Thank you for this amazing work. I’ve never seen so much good information, so vast a body of research, so well organized, so user-friendly and navigable.

    Comment by Sharon Osborn — September 23, 2010 @ 10:00 am | Reply

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