Tolerability of High-Dose Oral Δ-THC: Implications for Human Laboratory Study Design.

Δ-tetrahydrocannabinol (THC), the primary intoxicating compound in cannabis, has been tested extensively in controlled administration human studies. Some studies require a high THC dose that may induce adverse events (AEs), such as those testing novel treatments for cannabinoid overdose. Although there are ethical concerns related to administering high THC doses, there is no systematic analysis on studies utilizing these doses.

Pharmacokinetics of Two Nanoemulsion Formulations of Δ-Tetrahydrocannabinol in Rats.

The use of Δ-tetrahydrocannabinol (Δ-THC) has increased in recent years. Given that the oral absorption of cannabinoids in oil formulations is typically slow and variable, nanoemulsions may be an improved delivery vehicle. Therefore, we characterized the pharmacokinetics (PK) in Sprague-Dawley rats following the administration of three different oral formulations containing 10 mg/kg Δ-THC: a translucent liquid nanoemulsion, a reconstituted powder nanoemulsion, and a medium chain triglyceride (MCT) oil solution for comparison.

The risk of chronic psychedelic and MDMA microdosing for valvular heart disease.

Psychedelic microdosing is the practice of taking very low doses of psychedelic substances, typically over a longer period of time. The long-term safety of chronic microdosing is relatively uncharacterized, but valvular heart disease (VHD) has been proposed as a potential risk due to activation of the serotonin 5-HT receptor. However, this risk has not yet been comprehensively assessed.

Review of delta-8-tetrahydrocannabinol (Δ -THC): Comparative pharmacology with Δ -THC.

The use of the intoxicating cannabinoid delta-8-tetrahydrocannabinol (Δ -THC) has grown rapidly over the last several years. There have been dozens of Δ -THC studies dating back over many decades, yet no review articles have comprehensively covered these findings. In this review, we summarize the pharmacological studies of Δ -THC, including receptor binding, cell signalling, in vivo cannabimimetic activity, clinical activity and pharmacokinetics.

Selectivity Profile of the Tyrosine Kinase 2 Inhibitor Deucravacitinib Compared with Janus Kinase 1/2/3 Inhibitors.

Introduction: Deucravacitinib, a novel, oral, selective inhibitor of tyrosine kinase 2 (TYK2) signaling, acts via an allosteric mechanism by binding to the enzyme's regulatory domain instead of the catalytic domain. This unique binding provides high functional selectivity for TYK2 versus the closely related Janus kinases (JAKs) 1/2/3. Deucravacitinib was efficacious in phase 2 and 3 psoriasis trials, without clinical or laboratory parameters indicative of JAK 1/2/3 inhibition being observed.

A Phase Ib Study to Evaluate the MEK Inhibitor Cobimetinib in Combination with the ERK1/2 Inhibitor GDC-0994 in Patients with Advanced Solid Tumors.

Lessons Learned: Despite strong preclinical rationale, combined cobimetinib-mediated MEK inhibition and GDC-0994-mediated ERK inhibition was not tolerable on two 28-day dosing schedules in which GDC-0994 was given for 21 days continuously and cobimetinib administered over 21 days either continuously or intermittently. Adverse events were as expected for mitogen-activated protein kinase pathway inhibition, but overlapping and cumulative toxicities could not be managed on either dosing schedule. Pharmacokinetic parameters of cobimetinib and GDC-0994 given in combination were similar to those previously observed in monotherapy studies, so that there was no evidence of drug-drug interaction.

A First-in-Human Phase I Study to Evaluate the ERK1/2 Inhibitor GDC-0994 in Patients with Advanced Solid Tumors.

Purpose: ERK1/2 signaling can be dysregulated in cancer. GDC-0994 is an oral inhibitor of ERK1/2. A first-in-human, phase I dose escalation study of GDC-0994 was conducted in patients with locally advanced or metastatic solid tumors.

Correction to: Safety, Tolerability, and Pharmacokinetics of GDC-0276, a Novel Na1.7 Inhibitor, in a First-in-Human, Single- and Multiple-Dose Study in Healthy Volunteers.

The original version of this article unfortunately contained a mistake. A few entries were incorrect in Table 2.

Safety, Tolerability, and Pharmacokinetics of GDC-0276, a Novel Na1.7 Inhibitor, in a First-in-Human, Single- and Multiple-Dose Study in Healthy Volunteers.

Background And Objective: Current pain therapies often do not provide adequate pain relief and have dose-limiting adverse effects. Genetic evidence indicates that Na1.7 sodium channels are required for pain transduction and therefore represent an important therapeutic target.

Phase I study of the checkpoint kinase 1 inhibitor GDC-0575 in combination with gemcitabine in patients with refractory solid tumors.

Background: Checkpoint kinase 1 (Chk1) inhibition following chemotherapy-elicited DNA damage overrides cell cycle arrest and induces mitotic catastrophe and cell death. GDC-0575 is a highly-selective oral small-molecule Chk1 inhibitor that results in tumor shrinkage and growth delay in xenograft models. We evaluated the safety, tolerability, and pharmacokinetic properties of GDC-0575 alone and in combination with gemcitabine.

Translational Pharmacokinetic-Pharmacodynamic Modeling and Simulation: Optimizing 5-Fluorouracil Dosing in Children With Pediatric Ependymoma.

We previously investigated novel therapies for pediatric ependymoma and found 5-fluorouracil (5-FU) i.v. bolus increased survival in a representative mouse model.

Phase I dosage finding and pharmacokinetic study of intravenous topotecan and oral erlotinib in adults with refractory solid tumors.

Purpose: Topotecan is widely used for refractory solid tumors but multi-drug resistance may occur due to tumor expression of ATP-binding cassette (ABC) transporters. Since erlotinib, an inhibitor of the epidermal growth factor receptor, also inhibits several ABC transporters, we performed a phase I study to evaluate the safety, efficacy, and pharmacokinetics of intravenous topotecan given in combination with erlotinib.

Methods: Patients received 150 mg of oral erlotinib daily and a 30 min intravenous infusion of topotecan on days 1-5 of a 21-day cycle.

A phase-1 pharmacokinetic optimal dosing study of intraventricular topotecan for children with neoplastic meningitis: a Pediatric Brain Tumor Consortium study.

Purpose: We performed a phase-1 pharmacokinetic optimal dosing study of intraventricular topotecan (IT), administered daily 5×, to determine whether, the maximum tolerated dose of IT topotecan was also the pharmacokinetic optimal dose.

Patients And Methods: Patients received topotecan administered through an intraventricular access device (0.1 or 0.

Topotecan and vincristine combination is effective against advanced bilateral intraocular retinoblastoma and has manageable toxicity.

Background: New, effective chemotherapeutic agents are needed for intraocular retinoblastoma.

Methods: This institutional clinical trial sought to estimate the rate of response to 2 courses of vincristine and topotecan (VT) window therapy in patients with bilateral retinoblastoma and advanced disease (Reese-Ellsworth group IV or V) in at least 1 eye. The topotecan dose started at 3 mg/m(2) /day for 5 days and was adjusted to target a systemic exposure of 140 ± 20 ng/mL · hour.

Phase I study of vincristine, irinotecan, and ¹³¹I-metaiodobenzylguanidine for patients with relapsed or refractory neuroblastoma: a new approaches to neuroblastoma therapy trial.

Purpose: (131)I-metaiodobenzylguanidine (MIBG) is a targeted radiopharmaceutical with activity in patients with relapsed or refractory neuroblastoma. Irinotecan is a known radiosensitizer with activity in neuroblastoma. This phase I study aimed to determine the recommended phase 2 dose of MIBG together with fixed doses of vincristine and irinotecan.

Dose escalation of intravenous irinotecan using oral cefpodoxime: a phase I study in pediatric patients with refractory solid tumors.

Background: Administration of an oral cephalosporin allowed advancement of the dosage of oral irinotecan. This study investigates whether administration of an oral cephalosporin increases the maximum tolerated dose (MTD) of intravenous irinotecan.

Procedure: Irinotecan was administered intravenously on Days 1-5 and Days 8-12 of a 21-day cycle with continuous oral cefpodoxime starting 2 days prior to irinotecan.

Role of ATP-binding cassette and solute carrier transporters in erlotinib CNS penetration and intracellular accumulation.

Purpose: To study the role of drug transporters in central nervous system (CNS) penetration and cellular accumulation of erlotinib and its metabolite, OSI-420.

Experimental Design: After oral erlotinib administration to wild-type and ATP-binding cassette (ABC) transporter-knockout mice (Mdr1a/b(-/-), Abcg2(-/-), Mdr1a/b(-/-)Abcg2(-/-), and Abcc4(-/-)), plasma was collected and brain extracellular fluid (ECF) was sampled using intracerebral microdialysis. A pharmacokinetic model was fit to erlotinib and OSI-420 concentration-time data, and brain penetration (P(Brain)) was estimated by the ratio of ECF-to-unbound plasma area under concentration-time curves.

Whole-body physiologically based pharmacokinetic model for nutlin-3a in mice after intravenous and oral administration.

Nutlin-3a is an MDM2 inhibitor that is under investigation in preclinical models for a variety of pediatric malignancies, including retinoblastoma, rhabdomyosarcoma, neuroblastoma, and leukemia. We used physiologically based pharmacokinetic (PBPK) modeling to characterize the disposition of nutlin-3a in the mouse. Plasma protein binding and blood partitioning were assessed by in vitro studies.

Phase I study of vandetanib during and after radiotherapy in children with diffuse intrinsic pontine glioma.

Purpose: To evaluate the safety, maximum-tolerated dose, pharmacokinetics, and pharmacodynamics of vandetanib, an oral vascular endothelial growth factor receptor 2 (VEGFR2) and epidermal growth factor receptor inhibitor, administered once daily during and after radiotherapy in children with newly diagnosed diffuse intrinsic pontine glioma.

Patients And Methods: Radiotherapy was administered as 1.8-Gy fractions (total cumulative dose of 54 Gy).

Determination of the gamma-secretase inhibitor MK-0752 in human plasma by online extraction and electrospray tandem mass spectrometry (HTLC-ESI-MS/MS).

A sensitive and rapid HTLC-ESI-MS/MS method with an advanced online sample preparation was developed for determination of the gamma-secretase inhibitor MK-0752 in human plasma using an internal standard. Plasma samples (100 microL) were diluted and injected directly onto an online extraction column (Cohesive Cyclone MAX 0.5 mm x 50 mm, > 30 microm), the sample matrix was washed out with an aqueous solution, and retained analytes were eluted out and transferred directly to the analytical column (Phenomenex Gemini 3 micron C18 110A, 50 mm x 2.

Epidermal growth factor receptor polymorphisms and risk for toxicity in paediatric patients treated with gefitinib.

Purpose: To investigate associations between germline genetic variations in the epidermal growth factor receptor (EGFR) and toxicity in paediatric patients treated with gefitinib.

Patients And Methods: Gefitinib treatment and toxicity data from five paediatric clinical trials were combined. EGFR genotypes evaluated included -191C>A, -216G>T, Arg497Lys and intron 1 CA sequence repeat number.

P-glycoprotein, but not multidrug resistance protein 4, plays a role in the systemic clearance of irinotecan and SN-38 in mice.

The ATP-binding cassette transporters P-glycoprotein (ABCB1, MDR1) and multidrug resistance protein 4 (MRP4) efflux irinotecan and its active metabolite SN-38 in vitro, and thus may contribute to system clearance of these compounds. Mdr1a/b(-/-), Mrp4(-/-), and wild-type mice were administered 20 or 40 mg/kg irinotecan, and plasma samples were collected for 6 hours. Irinotecan and SN-38 lactone and carboxylate were quantitated and data were analyzed with nonlinear mixed-effects modeling.

IL-33 augments substance P-induced VEGF secretion from human mast cells and is increased in psoriatic skin.

The peptide substance P (SP) has been implicated in inflammatory conditions, such as psoriasis, where mast cells and VEGF are increased. A relationship between SP and VEGF has not been well studied, nor has any interaction with the proinflammatory cytokines, especially IL-33. Here we report that SP (0.

Stability of cyclophosphamide in extemporaneous oral suspensions.

Background: Cyclophosphamide, an alkylating agent, is widely used for the treatment of many adult and pediatric malignancies. The stability of cyclophosphamide in aqueous- and methylcellulose-based oral suspending vehicles is currently unknown.

Objective: To develop and validate a stability-indicating high-performance liquid chromatography (HPLC) method to measure cyclophosphamide concentrations in simple syrup and Ora-Plus, and assess the 56-day chemical stability and physical appearance of cyclophosphamide in these suspensions at both room temperature (22 degrees C) and 4 degrees C.