Jess asked
How long should you wait in between taking CBD oil and Vistaril?
At a glance
- There is a lack of data available regarding whether or not there is a clinically significant interaction between CBD and Vistaril (hydroxyzine).
- At the very least, both are known to cause sedation, and therefore, taking both can cause you to feel more tired.
- The effects of Vistaril last around four to six hours per dose, so, if necessary, you can separate doses of CBD and Vistaril accordingly.
Answer
There are no known drug interactions between Vistaril (hydroxyzine) and CBD (cannabidiol) oil. However, both can cause sedation and therefore, caution is recommended when combining them and you should not drive/operate heavy machinery until you know how they affect you.
In addition, while no interactions have been reported between CBD and Vistaril (hydroxyzine), there are some theoretical ones that are important to be aware of. These are discussed below.
What Is CBD (Cannabidiol)?
Cannabidiol, often referred to simply as 'CBD', is one of the many constituents of marijuana and is known to be an active component in regard to activity within the endocannabinoid system.
Unlike THC (delta-9-tetrahydrocannabinol), CBD is thought to be 'non-psychoactive' in that it doesn't cause a 'high' or euphoria. Nevertheless, it certainly does affect the central nervous system as studies show it can be beneficial for symptoms of anxiety and can cause sedation.
CBD has been investigated for a wide variety of therapeutic effects, including:
- Chronic Pain
- PTSD
- Multiple sclerosis
- Parkinson's Disease
- Epilepsy
- Huntington's Disease
In addition, CBD may make high THC preparations more tolerable for individuals as it can 'attenuate' or reduce the 'high' experienced.
CBD Side Effects
CBD is well tolerated in most individuals and is not associated with dependence or withdrawal symptoms, even after extended use.
CBD can cause sedation and a general feeling of tiredness, but is not associated with respiratory depression and has been used safely with CNS depressants such as opioids and benzodiazepines.
Nevertheless, CBD can cause additive drowsiness when used with other medications with similar side effects (e.g. hydroxyzine, a sedating antihistamine).
CBD Drug Interactions
There is a lack of information regarding interactions with CBD products and it appears that some may be dose-related (meaning higher doses increase the risk of interaction).
Potential interactions stem from the fact that CBD may inhibit certain CYP metabolizing enzymes in the liver, including:
- CYP 3A4
- CYP 2C19
- CYP 1A1
- CYP 2B6
- CYP 2C9
When a metabolizing enzyme is inhibited, it cannot break down a drug as effectively or as quickly, leading to increased concentrations. This can increase the risk of side effects. There are exceptions, but generally, this is the case.
It should be noted that most interaction studies with CBD have been only done in animals and the extent of potential interactions in humans isn't well known.
What Is Vistaril (Hydroxyzine)?
Hydroxyzine is a sedating antihistamine, also known as an H1-blocker. It is specifically classified as a piperazine antihistamine, similar in structure to meclizine and cetirizine.
Hydroxyzine is effective in treating histamine-induced itching (i.e. pruritus) and related allergic conditions, such as hives. It is also indicated as an alternative treatment for anxiety disorders (e.g., generalized anxiety), due to its sedative and anxiolytic effects.
The onset of effect for hydroxyzine occurs between 15 to 60 minutes after taking by mouth. Each dose has a duration of action around 4 to 6 hours although the anti-itch effects can last for several days.
Hydroxyzine is known to be metabolized through the liver, with a variety of metabolizing enzymes involved, including:
- CYP2D6
- CYP3A4
Potential Interaction
Based on the known metabolism of CBD and Vistaril (hydroxyzine), there is a chance the CBD inhibition of metabolizing enzymes (notably CYP3A4) could increase hydroxyzine concentrations in the body (due to decreased metabolism).
This could potentially increase side effects, such as lethargy and sedation. It is important to note that this particular interaction/increase in side effects has not been reported, but is more theoretical.
If you are going to be combining CBD and hydroxyzine, it may be prudent to try them both in the evening or at a time where you can safely assess your response to the medication.
In addition, be sure to let your doctor know of all the medication you are taking so they can provide appropriate medical guidance for your particular situation.
The effects of hydroxyzine, as mentioned above, last between 4 to 6 hours. CBD oil similarly (although less is known about it), has a duration of action around the same time frame or slightly longer (4-8 hours).
If you want to avoid potential additive side effects, you may wish to separate CBD and hydroxyzine that amount of time (4-8 hours).
References
- Statin-induced rhabdomyolysis: a complication of a commonly overlooked drug interaction. PubMed
- Vistaril Prescribing Information. Pfizer
- Classic histamine H1 receptor antagonists: a critical review of their metabolic and pharmacokinetic fate from a bird's eye view. PubMed
- In Vitro inhibition of CYP3A4 by histamine H1 receptor antagonists? ResearchGate
- Hydroxyzine (Compound). PubChem
- Epidiolex Prescribing Information. AccessFDA
- Multicenter, Double-Blind, Randomized, Placebo-Controlled, Parallel-Group Study of the Efficacy, Safety, and Tolerability of THC:CBD Extract and THC Extract in Patients with Intractable Cancer-Related Pain. ScienceDirect
- Hypnotic and antiepileptic effects of cannabidiol. PubMed
- Characterization of major phytocannabinoids, cannabidiol and cannabinol, as isoform-selective and potent inhibitors of human CYP1 enzymes. PubMed
- Potent inhibition of human cytochrome P450 3A isoforms by cannabidiol: role of phenolic hydroxyl groups in the resorcinol moiety. PubMed
- Controlled clinical trial of cannabidiol in Huntington's disease. PubMed
- Cannabidiol for the treatment of psychosis in Parkinson's disease. PubMed
- Oromucosal Δ9-tetrahydrocannabinol/cannabidiol for neuropathic pain associated with multiple sclerosis: An uncontrolled, open-label, 2-year extension trial. ScienceDirect
- Multiple mechanisms involved in the large-spectrum therapeutic potential of cannabidiol in psychiatric disorders. Royal Society Publishing
- Medical Marijuana for Treatment of Chronic Pain and Other Medical and Psychiatric Problems A Clinical Review. JAMA Network
- Effects of ipsapirone and cannabidiol on human experimental anxiety. PubMed
- The diverse CB1 and CB2 receptor pharmacology of three plant cannabinoids: delta9-tetrahydrocannabinol, cannabidiol and delta9-tetrahydrocannabivarin. PubMed
