Pharmacokinetics of escalating single-dose administration of cannabidiol to cats

CBD for pets: navigating quality assurance, safety standards, and marketing strategies

As the human cannabinoid (CBD) market grows, there is an inevitable transfer of the same or similar products into the veterinary sector. Advances in veterinary medicine and care of companion animals has led to extended life expectancy and consequently, there is an increased incidence of age-related chronic conditions that compromise quality of life. CBD products may alleviate these conditions. Research into CBD for companion animal species is on the rise, however, we found that there are no licensed veterinary CBD products available in the market due to a lack of appropriate testing and/or data. Here we outline the data that is available and show that the regulatory, and safety considerations around these products needs further consideration and this encompasses many products currently available on the market. Changes in regulations and further research for quality assurance are paramount to distribution of safe and applicable products for companion animals.

Investigating the effect a single dose of cannabidiol has on measures of stress in cats when being transported in a carrier and meeting a novel person in an unfamiliar environment

Domestic cats (Felis Catus) are often exposed to stimuli that have the potential to negatively impact their welfare. These can include situations such as veterinary visits, travel, changes to their home environment, and interactions with unfamiliar people or pets. Cannabidiol (CBD)-infused pet products have grown in popularity in recent years, as pet owners search for ways to calm and relax their pets. However, research into the pharmacokinetic properties of CBD in cats is limited and investigations into its efficacy are in their infancy. The present study aimed to explore the effect of a single 4 mg/kg bodyweight dose of a THC-free CBD distillate on measures of stress in cats when experiencing a composite stress-paradigm, consisting of cat carrier travel and exposure to a novel person within an unfamiliar environment. Physiological and behavioural indicators of stress were collected pre-, during, and post-testing. No significant effect of CBD was observed on serum cortisol, IgA, or glucose, either before or immediately after the stress-paradigm (all p > 0.05). This was true despite cortisol being shown to significantly increase post-test for both treatments (both p < 0.001), suggesting that travel and meeting a novel person successfully induced a stress response within this population of cats. No significant differences in any measures of cat behaviour, including latency to approach the novel person, were observed between treatments (all p > 0.05). Overall, no influence of CBD was observed in cats, suggesting further research into appropriate dosage, delivery matrices, and other conditional factors, such as individual coping styles, should be considered.

Perioperative Analgesic and Sedative Effects of Cannabidiol in Cats Undergoing Ovariohysterectomy

The aim of this study was to evaluate the perioperative analgesic and sedative effects of oral CBD in cats undergoing ovariohysterectomy. Twenty-two cats were assigned to receive either oral cannabidiol oil (2 mg/kg, CBD group, n = 12) or placebo oil (0.1 mL/kg, Placebo group, n = 10) 60 min before the premedication. The anesthetic protocol included dexmedetomidine/meperidine, propofol, and isoflurane. Intravenous fentanyl was given to control cardiovascular responses to surgical stimulation. Pain was assessed at 0.5, 1, 2, 4, 6 and 8 h post-extubation using the UNESP-Botucatu multidimensional composite pain scale and the Glasgow feline composite-measure pain scale. Sedation scores were assessed at the same timepoints and at 15 min after the premedication. Morphine was administered as rescue analgesia. Higher sedation scores were recorded in the CBD group at 15 min after premedication (p = 0.041). Intraoperatively, more cats required fentanyl in the Placebo group than in CBD group (p = 0.028). The pain scores did not differ between groups, except at 0.5 h post-extubation when lower scores were detected in the CBD group (p = 0.003-0.005). Morphine was required in 100% of the animals in both groups. CBD increased preoperative sedation and decreased intraoperative analgesic requirements, with minimal evidence of postoperative analgesic benefits over the placebo.

Pharmacokinetic of two oral doses of a 1:20 THC:CBD cannabis herbal extract in cats

Objective

To determine the pharmacokinetics (PK) of two oral doses of a Cannabis herbal extract (CHE) containing 1:20 THC:CBD in 12 healthy Domestic Shorthair cats.

Methods

Single-dose PK were assessed after oral administration of CHE at low or high dose (2 mg CBD + 0.1 mg THC, or 5 mg CBD + 0.25 mg THC per kg bw, respectively; n = 6 per group) in fasting cats. Blood samples were drawn up to 48 h following CHE administration. Plasma samples were analyzed for CBD, THC, and metabolites 6-OH-CBD, 7-OH-CBD, 11-OH-THC, and THC-COOH using a previously validated LC-MS/MS method.

Results

CBD and THC were quickly absorbed (mean Tmax of 2.4-2.9 h). Maximum plasma concentrations (Cmax) ranged from 36-511 ng/mL and 6.8-61 ng/mL for CBD and THC, respectively. Elimination was initially rapid for both CBD and THC, though a prolonged elimination phase was noted for CBD in some cats (T1/2 λ up to 26 h). Dose-adjusted Cmax and AUC0-last values were not statistically significantly different (p > 0.05) between dose groups indicating CBD and THC concentrations increased in a manner proportional (linear) to the dose. Dose-adjusted THC Cmax and AUC0-last were significantly higher than the corresponding dose-adjusted CBD parameters (p < 0.01). Low concentrations of the metabolite 6-OH-CBD were quantified but metabolites 7-OH-CBD, 11-OH-THC, and THC-COOH were not detected in any plasma samples. Inter-individual variance was notable. Salivation shortly after dosing was observed in two cats in the high dose group; these animals had substantially lower cannabinoid concentrations than other cats in this group. No adverse clinical signs (including vomiting, change in mentation or other neurological signs) were noted.

Clinical significance

Although cats did not display adverse effects after administration of a single oral dose of 1:20 THC:CBD CHE formulation at 2 or 5 mg CBD/kg bw, observed plasma concentrations were highly variable but generally lower than in dogs receiving the same dose and formulation. Administration of CHE in the fasting state may not optimize CBD absorption, and oral dosing may be challenging when administering an oil-based CHE in some cats.

Healthy cats tolerate long-term daily feeding of Cannabidiol

Cannabidiol (CBD)-containing products are widely commercially available for companion animals, mirroring popularity in human use. Although data on the safety and efficacy of long-term oral supplementation are increasing in dogs, evidence remains lacking in cats. The purpose of these studies was to address gaps in the knowledge around the long-term suitability and tolerance of a tetrahydrocannabinol (THC)-free CBD distillate in clinically healthy cats. The studies were randomized, blinded, and placebo-controlled. The first study supplemented cats with either a placebo oil (n = 10) or with 4 mg/kg body weight (BW) CBD in placebo oil (n = 9) daily, with a meal, for 4 weeks. The concentration of CBD in plasma was measured over 4 h at d0 (first dose) and again at d14 (after 2 weeks of daily dosing). The second study supplemented cats daily with either placebo oil (n = 10) or 4 mg/kg BW CBD in placebo oil (n = 10) for a period of 26 weeks. A comprehensive suite of physiological health measures was performed throughout the study at baseline (week 0) and after 4, 10, 18, and 26 weeks of feeding, followed by a 4-week washout sample (week 30). Postprandial plasma CBD time course data, at both d0 and d14, showed a peak plasma CBD concentration at 2 h after the dose. This peak was 251 (95% CI: 108.7, 393.4) and 431 (95% CI, 288.7, 573.4) ng/mL CBD at d0 and d14, respectively, and the area under the curve concentration was higher by 91.5 (95% CI, 33.1, 149.9) ng-h/mL after 2 weeks of supplementation (p = 0.002). While in the first study the CBD group displayed increased alanine aminotransferase (ALT; 68.7 (95% CI, 43.23, 109.2) U/L) at week 4 compared to the placebo control group [1.44-fold increase (95% CI, 0.813, 2.54)], statistical equivalence (at 2-fold limits) was found for ALT across the duration of the second, long-term study. All other biochemistry and hematology data showed no clinically significant differences between supplement groups. Data presented here suggest that a THC-free, CBD distillate fed at a dose of 4 mg/kg BW was absorbed into plasma and well tolerated by healthy cats when supplemented over a period of 26 weeks.

Cannabidiol plasma determination and pharmacokinetics conducted at beginning, middle and end of long-term supplementation of a broad-spectrum hemp oil to healthy adult dogs

Introduction

Veterinary hemp products containing cannabidiol (CBD) and negligible psychoactive (THC) have increased popularity since hemp (with <0.3% THC) was removed from schedule 1 substances under the Controlled Substances Act in 2018. This was accompanied by increased CBD research, mostly on the short-term safety and efficacy for inflammatory and neurological conditions. It is imperative to understand how CBD is metabolized or accumulated in the body long-term, thus the goal of the present work was to determine monthly plasma CBD concentrations, as well as changes in pharmacokinetic (PK) parameters in chronically dosed dogs.

Methods

The study was a masked, placebo-controlled, randomized design. Six adult beagles were assigned to placebo, 5 and 10 mg/kg/day CBD treatment groups. Dogs received oral oil treatment once daily for 36 weeks. Blood was collected once every 4 weeks pre- and postprandially for CBD plasma determination (at 0 and 2 h). Pharmacokinetics were conducted at 0, 18 and 36 weeks. Pharmacokinetics and monthly CBD plasma data of dogs who received CBD were analyzed as repeated measures over time using a mixed model, with significance at α = 0.05.

Results

Average plasma CBD at 5 and 10 mg/kg were 97.3 ng/mL and 236.8 ng/mL pre-prandial, 341 ng/mL and 1,068 ng/mL postprandial, respectively. PK parameters suggested CBD accumulation over time, with significant increases in Cmax and AUC at both the 18 and 36-week timepoints. Cmax and AUC were dose proportional. Half-life demonstrated large inter-individual variations and increased (p < 0.05) at weeks 18 and 36 compared to baseline. Volume of distribution was not affected by time or treatment, while MRT increased, and clearance decreased over time (p < 0.05).

Conclusions and clinical importance

Chronic administration of CBD to healthy adult dogs led to a dose-proportional accumulation in the body for 36 weeks, which was confirmed by an increased half-life, total exposure, mean residence time and plasma peak. Our data also suggests that CBD plasma levels may have less daily variation if administered twice daily.

Disposition of a single oral dose of a cannabidiol medication in healthy cats

The historical use of the marijuana plant for medicinal purposes is long. One of the historical uses has been for the treatment of epilepsy. Recently, the Food and Drug Administration has approved a highly purified cannabidiol medication for the add on therapy in people with certain forms of epilepsy. With the increase interest of the use of cannabidiol in the veterinary community, the aim of this study was to describe the disposition of a single dose of a cannabidiol medication in healthy cats in both the fed and fasted state. Pharmacokinetic analysis reveals that relative bioavailability of cannabidiol shows a near eleven-fold increase when administered in the fed state compared to the fasted state. Additionally, concentrations achieved at a dose of 5 mg/kg, may be sufficient to explore the therapeutic potential in cats with epilepsy.