Safe use of cannabis
The following is general information about the safe and effective use of cannabis for medical purposes. It is recommended that patients and carers consult with their doctor to ensure that the patient, especially those patients using cannabis for the first time receive safe, correct and efficient treatment.
It is also strongly recommended that professional advice and guidance is sought on strains, forms, dosage (initial doses, gradual increase and maintenance doses), potential side effects and contraindications. Patients and carers should also research the products themselves and read information that is specific to the product being used.
New patients
Cannabis treatment doesn’t always have an immediate effect on conditions or symptoms. It is recommended that patients using medical cannabis products for the first time, do so in a safe and comfortable environment under the care, supervision and guidance of a friend, carer, another patient with experience in the use of cannabis or a registered doctor or nurse. Patients should be seated when consuming cannabis and drink something sweet or eat something during use.
Children and vulnerable patients
Extra caution should be used in treating children and vulnerable patients. Parents and carers should receive professional advice and guidelines on the initial dose and on gradual increases in dosage or decrease in other medications from a doctor with experience with the use of cannabis.
Methods of consumption and dosage
The method of consumption has a determining effect on the way the treatment will affect symptoms. The methods differ in the dose required, the amount of time it takes to feel the effects of the treatment and the amount of time the effects last.
The appropriate dose for each patient is determined by taking into consideration any medications the patient is on, their weight and energy level, the symptoms they have and their intensity and according to the consumption methods and strains that are combined. In some cases it is possible to treat a disease and symptoms with lower cannabis doses than the doses that generate psychotropic side effects.
Start slow and increase in small amounts only until the optimal dose is reached as you would for other medications.
During the first few weeks of treatment the dose can be titrated and increased slowly until the optimal amount is reached. Once an optimal dose is achieved wait six hours before taking another dose. Do not take two doses simultaneously to make up for a missed dose. Be patient as sometimes it can take one to two months of dose adjustments until the optimal dose is achieved and to obtain the full effects and benefits of the treatment.
Oral consumption: Caution needs to be taken when using cannabis orallly either by swallowing, dissolved in the mouth or absorbed under the tongue as the effects can last for up to 48 hours.
It is recommended to start slow by taking a small quantity (based on the level of active ingredients in the product) and wait two hours to feel the full effects. If the effect is sufficient continue with this dose. If the effect is insufficient take another small amount and wait (repeat as necessary until the desired dose is reached). Consumption with fatty and/or sweet food can hasten and improve the absorption in the body.
Smoking or vaporising: General guidelines for smoking or vaporizing are to inhale two or three times. Each inhalation should be brief and followed by a deep breath in and out of the lungs. Wait several minutes or longer for the cannabis to take effect. If the effect is sufficient use this as a dose. If the effect is insufficient inhale two or three additional times (based on the feeling) and wait. Repeat as necessary until the optimal dose is reached. It is important to note that smoking may damages one’s health. Alternative oral methods of use are recommended.
Side Effects
The side effects from the use of medical cannabis are not numerous. Most side effects are usually mild and dissipate shortly after the patient becomes accustomed to its use. Cannabis may cause two categories of side effects.
Physiological effects: may include dizziness, weakness, tiredness, irregular heartbeat (faster or slower), lower blood pressure and blood sugar levels, increased appetite, red eyes, dryness in the mucous membranes such as the mouth and eyes and lack of coordination and balance.
Cognitive side effects: may include impairment to short-term memory and train of thought and an impaired perception of time and space. Regular use of large amounts (more than 5 grams per day) can lead to cognitive impairment but this effect dissipates when use is decreased or ceased. In youth cognitive impairment could be lasting.
Side effects that may occur from overdose and that require special attention: fainting, significant changes in blood pressure, pulse and blood sugar levels or in respiration rates.
A high dose of cannabis can in some cases cause a temporary psychotic attack, anxiety, delusions or hallucinations for people that are pre-disposed.
Warnings
For patients in these categories referred to below, it is recommended to seek professional advice before commencing the use of cannabis. Cease use or seek immediate medical attention if significantly affected or if significant changes or side effects occur.
In patients where there is a known sensitivity to any of the ingredients.
Patients with heart and stroke conditions or a history of epilepsy are advised to take caution.
In pregnancy or when nursing or breast feeding.
If there is a personal or family history of schizophrenia or other mental illness except depression.
Changes in blood pressure, pulse rate as well as changes in blood sugar levels are possible. If you are currently taking other medication for blood pressure or diabetes monitor blood pressure, pulse and blood sugar levels three times a day over the course of the first three days of use. If there are significant changes advise and consult your doctor in order to find the right treatment plan.
If the patient shows signs of confusion, severe restlessness, a change in consciousness, or has a prolonged panic attack stop taking the product immediately and consult your doctor.
The use of cannabis may impair alertness and therefore caution should be exercised when engaging in activities such as driving a car, operating dangerous machinery and any other activity which requires alertness.
The use of cannabis with alcohol can cause a cumulative decrease in coordination, concentration and ability to react.
Drug Interactions
There is a cumulative effect for cannabis in conjunction with opiates, alcohol, and sleep medications. If there is a need to use cannabis in conjunction with opiates, anxiety or sleep medication, seek further advice about reducing the dose of these medications.
Hallucinations are possible when cannabis is taken in conjunction with SSRI anti-depressants. Seek advice on reducing the dose of the medication or the cannabis.
Because of the first-pass effect that happens to cannabinoids in the liver (especially when consumed orally) there may be a risk with using cannabis with medications that are metabolized by the enzymes CYP3A4 and CYP2C9 in the cytochrome. The combination of cannabis and these types of medications can either increase the biological availability of cannabis or increase its side effects.
Medications that inhibit these enzymes: include macrolides (especially clarithromycin and erythromycin), antimycotics (such as ketoconazole, fluconazole, itraconazole and miconazole), calcium antagonists (especially diltiazem and verapamil), HIV protease inhibitors (especially ritonavir) isoniazid and amiodarone be aware of side effects and seek advice about reducing daily cannabis dose.
Medications that inhibit the metabolism of cannabis through the enzymes mentioned above are: carbamazepine, rifampicin, troglitazone, rifabutin, primidone, phenytoin, phenobarbital and also the herbal plant Hypericum perforatum.
If a patient begins cannabis treatment with these medications there is a likelihood that an increased dose of medical cannabis will be necessary. If a patient has found the appropriate dose of cannabis while taking these medications, the dose will need to be reduced when these medications are ceased being taken.
Pharmacodynamic Properties
Cannabinoids impact cannabinoid receptors in the body. Two main receptors are known, CB1 and CB2. CB1 is present mostly in the nervous system and CB2 in the periphery especially in the immune and digestive systems. THC binds to both of these receptors in the body. CB1 is responsible for THC’s neural properties – relaxation, pain relief (though CB2, scattered in the peripheral nerves also contributes to pain relief), tremors, spasms and in higher doses on psychotropic symptoms and euphoria. CB2 is responsible for the anti-inflammatory properties of cannabinoids. CBD the main non-psychotropic cannabinoid is active primarily on the anti-inflammatory and anti-oxidizing mechanisms.
Pharmacokinetic Properties
Absorption: The absorption of cannabis varies based on the consumption methods. When inhaled, the cannabinoids are absorbed through the lungs to the blood stream in just a few minutes and reach a maximum concentration in the blood within 10-15 minutes. In this consumption form, the biological availability is at 40%. Absorption is heavily dependent on physiological differences among patients, the temperatures the cannabis was heated to and the duration of the heating and the time between inhalations, the number of inhalations, the length of each inhalation and the tolerance of the lungs.
When swallowed, the cannabis is absorbed more slowly than smoking and has a larger variance from patient to patient. The maximum concentration of cannabinoids in the blood stream appear after 45 minutes to two hours (depending on the patient and whether the medication was consumed with food or without. Consumption with fatty or sweet food improves and hastens absorption). The biological availability is about 10% or just one fourth of the biological availability received through inhalation mostly because of the first pass effect of the liver.
Dispersion: After absorption, the cannabinoids are dispersed throughout the entire body. Their concentration rises the quickest in tissues with high blood supply levels such as the brain, lungs, liver, and kidneys. Some cannabinoids accumulate in fat tissues. Cannabinoids bind strongly to plasma proteins. Their volume of dispersion is about 10 liters per kilogram of body weight.
Metabolism and discharge: In the liver, enzymes from the cytochrome family, CYP3A4 and CYP2X9 turn THC into 11-THC-hydroxy (THC-OH-11), the active metabolite, which turns into THC-carboxyl (THC-COOH) that is non-active. The half-life of THC and THC-OH-11 in the plasma is 25-36 hours. In the body, the half-life can reach up to seven days. In addition other non-active metabolites are produced. THC metabolites are excreted in urine up to several weeks after cannabis is consumed.