Cannabidiol (CBD) is known to modify the effects of Delta-tetrahydrocannabinol (THC) by decreasing anxiety and antagonizing other THC-effects. As a reason, pharmacodynamic as well as pharmacokinetic mechanisms were suggested. In context of the use of cannabis-based medicine extracts for therapeutic purposes, a study was performed in a double-blind and placebo-controlled cross-over design in which each of 24 volunteers (12 male and 12 female, age 18-45 years) obtained soft-gelatin capsules with 10 mg THC (THC-set), cannabis extract containing 10 mg THC +5.4 mg CBD (CAN-set) or placebo in weekly intervals. Blood samples were taken 30 minutes before and 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours, 9 hours and 24 hours after the intake. The concentrations of THC, of its metabolites 11-OH-THC, THC-COOH and of CBD in the plasma samples were determined by automatic solid phase extraction, derivatization with N,O-bis(trimethylsilyl)triflouroacetamide and gas chromatography-mass spectrometry. The concentration versus time curves (maximum concentrations Cmax, corresponding time tmax and areas under the curves AUC) were evaluated by statistical methods with respect to equivalence or differences between the CAN-set and the THC-set. Furthermore, the intra-individual ratios of Cmax and AUC for 11-OH-THC/THC, THC-COOH/THC and THC-COOH/11-OH-THC were compared between the THC-set and the CAN-set. Despite the large variation of the data, evidence emerged from the total of the results that CBD partially inhibits the CYP 2C catalyzed hydroxylation of THC to 11-OH-THC. The probability for this inhibition is particularly high for oral intake because THC and CBD attain relatively high concentrations in the liver and because of the high first-pass metabolism of THC. However, the effect of CBD is small in comparison to the variability caused by other factors. Therefore, a pharmacokinetic reason for the differences determined between pure THC and cannabis extract is improbable at the doses chosen in this study. Significantly higher AUC and Cmax and shorter tmax were found for females as compared with males.

Besides the psychoactive Delta(9)-tetrahydrocannabinol (THC), hashish and marijuana as well as cannabis-based medicine extracts contain varying amounts of cannabidiol (CBD) and of the degradation product cannabinol (CBN). The additional determination of these compounds is interesting from forensic and medical points of view because it can be used for further proof of cannabis exposure and because CBD is known to modify the effects of THC. Therefore, a method for the simultaneous quantitative determination of THC, its metabolites 11-hydroxy-Delta(9)-tetrahydrocannabinol (11-OH-THC) and 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THC-COOH), CBD and CBN from plasma was developed. The method was based on automatic solid-phase extraction with C(18) ec columns, derivatization with N,O-bistrimethylsilyltrifluoroacetamide (BSTFA), and gas chromatography-electron impact ionization-mass spectrometry (GC-EI-MS) with deuterated standards. The limits of detection were between 0.15 and 0.29 ng/mL for THC, 11-OH-THC, THC-COOH, and CBD and 1.1 ng/mL for CBN. The method was applied in a prospective pharmacokinetic study after single oral administration of 10 mg THC alone or together with 5.4 mg CBD in cannabis extract. The maximum plasma concentrations after cannabis extract administration ranged between 1.2 and 10.3 ng/mL (mean 4.05 ng/mL) for THC, 1.8 and 12.3 ng/mL (mean 4.9 ng/mL) for 11-OH-THC, 19 and 71 ng/mL (mean 35 ng/mL) for THC-COOH, and 0.2 and 2.6 ng/mL (mean 0.95 ng/mg) for CBD. The peak concentrations (mean values) of THC, 11-OH-THC, THC-COOH, and CBD were observed at 56, 82, 115, and 60 min, respectively, after intake. CBN was not detected. Caused by the strong first-pass metabolism, the concentrations of the metabolites were increased during the first hours after drug administration when compared to literature data for smoking. Therefore, the concentration ratio 11-OH-THC/THC was discussed as a criterion for distinguishing oral from inhalative cannabis consumption.

Borderline personality disorder (BPD) is characterized by interpersonal difficulties, whereby patients are negatively biased concerning the evaluation of others' trustworthiness. Here, we examined the effect of oxytocin on interpersonal behavior of BPD patients in a trust game, emphasizing the assessment of facial attractiveness of the patients' counterparts in the game, and patients' history of childhood trauma. Thirteen BPD patients and thirteen healthy controls played a trust game after receiving oxytocin or placebo in a randomized, double-blind crossover design. Childhood trauma was evaluated using the Childhood Trauma Questionnaire (CTQ). Patients transferred less money in the oxytocin condition compared to placebo. While healthy controls transferred more money units (MUs) to attractive counterparts than to unattractive ones only after the administration of oxytocin, BPD patients showed this pattern in both conditions. Emotional neglect during childhood negatively correlated with the amount of MUs transferred by patients under oxytocin, but not placebo. Oxytocin had a trust-lowering effect in BPD, which was correlated with patients' history of childhood trauma. Patients' evaluation of interpersonal trust seems to depend more on attractiveness features of their counterparts than in controls, a finding that may have important implications for further research on the usefulness of "prosocial" peptides as an adjunct to psychotherapeutic interventions.

Benzodiazepines are generally highly effective when first given, but they should generally be given only for strict indications and for a limited time. If these drugs still need to be given beyond the short term, timely referral to a specialist is indicated, and possibly also contact with the addiction aid system.