Medicinal Cannabis and Other Drug Interactions
Medicinal cannabis and other drug interactions
As with any medication, it is imperative that patients are warned that they must not combine medicinal cannabis with other medication without proper consultation and clearance from a doctor.
While most types and forms of medicinal cannabis have relatively low toxicity levels, interactions with certain medications can lead to severe adverse effects.
A medical practitioner should comprehensively examine both a patient’s entire medical history, as well as reviewing their current medication before considering a prescription of medicinal cannabis.
Which medications cannot be used with CBD?
While a patient’s medication protocol should undergo a thorough evaluation before any additional medication is added, there are certain drugs that cannot be used with CBD, due to the medicinal cannabis interactions with these medications and the serious adverse effects of these interactions.
CNS depressants
There is evidence to suggest that combining CBD with CNS depressants (such as drugs in the opioid family or alcohol) can have an additive effect, where the impact of both medications may be heightened.
In addition, some studies have shown the combination can lead to drowsiness or ataxia, resulting in slurring, lack of coordination and deterioration of fine motor skills.
Anti-coagulants
When anti-coagulants, such as warfarin, are combined with medicinal cannabis, there is research to suggest it increases the risk of bleeding, which is extremely dangerous.
By inhibiting the body’s metabolism of warfarin, the cannabis medication interaction could result in increased plasma concentrations, again increasing the risk of internal bleeding.
Anti-seizure medications
Research into the interaction between medicinal cannabis and anti-seizure medication is ongoing. While some studies have indicated the positive impact medicinal cannabis may have on those suffering from epilepsy, adverse effects have also been reported clinically, with cognitive distortions and an increase in psychosis, although these effects appear to be case by case.
Anti-psychotic medications
While studies have been predominantly animal-based, research suggests that pharmacodynamically, the cannabinoids found within medicinal cannabis may reduce the anti-psychotic efficacy of anti-psychotic drugs, increasing the danger of adverse medicinal cannabis interactions with these types of medications.
Can medicinal cannabis be mixed with alcohol?
Just as patients should refrain from mixing other forms of prescription medication with alcohol, the same applies to medicinal cannabis.
Research is ongoing, but as above, there is evidence which suggests medicinal cannabis interactions with alcohol may enhance and amplify the effects of both chemicals. As there are studies to suggest both CBD and alcohol consumption are linked to sedation, it is unwise to combine the two.
What else needs to be taken into account when considering medicinal cannabis interactions with medications?
In addition to warning patients about medicinal cannabis’ adverse interactions with existing medication, medical professionals will also need to take the specific details of the patient and the prescription itself under consideration before prescribing.
Individual response
Individual health factors, such as a history of anxiety, depression or mental health concerns must be factored in when weighing up the benefits of prescribing medicinal cannabis.
This should be an extensive examination that goes beyond the patient to consider family history and behaviours, as well as social circumstances and ‘at risk’ behaviour.
Another area to factor in is the patient’s employment; will they be operating heavy machinery or driving, as part of their role? If so, medicinal cannabis is not to be advised due to potential impairments. It is also illegal to drive in almost all states of Australia with any THC in your system.
Method of ingestion
Another element to consider is the proposed method of ingestion. As each method of ingestion offers a different speed and level of absorption, the way that a patient ingests medicinal cannabis will impact its interaction with other medications.
Inhalation, in the form of vaping, leads to quicker absorption than medicinal cannabis that is orally ingested. This means its interaction with other medication is likely to be acute, although other factors, like patient gender, build, and metabolism will also play a role.
Dosage
Perhaps the most obvious component of prescribing medicinal cannabis and its potential medication interactions is the dosage. The higher the dosage, the more profound the interaction with another medication may be.
As with other medications, it’s advised that a patient begins on a smaller, milder dosage so that the impact of the medication can be safely established. The dosage can then be adjusted as required.
What else do healthcare professionals need to make their patients aware of when prescribing medicinal cannabis?
As with all medications, healthcare professionals need to make their patients aware of the potential side-effects of medicinal cannabis. They also need to highlight the risks of mixing medicinal cannabis with any other medications, as outlined above.
Healthcare professionals prescribing medicinal cannabis should also outline the legal ramifications around driving with THC in your system, as well as pointing out any risks involved for any pregnant or breast-feeding women. To mitigate these risk factors, they should schedule regular check-ups, and encourage patients to track their symptoms to identify any adverse patterns, and seek medical assistance if they require it.
Find out more
Healthcare professionals can find out more useful information about medicinal cannabis and its administration by accessing the healthcare professionals portal. If you have any questions about our products, contact us today.
