Explore the vast range of titles available.

Background and Objective Patients with type 2 diabetes mellitus often have impaired renal function or may have impaired hepatic function, which can pose significant safety and tolerability issues for anti-hyperglycaemic pharmacotherapies. Therefore, the pharmacokinetics and tolerability of saxagliptin and its pharmacologically active metabolite, 5-hydroxy saxagliptin, in nondiabetic subjects with mild, moderate or severe renal or hepatic impairment, or end-stage renal disease (ESRD) were compared with saxagliptin and metabolite pharmacokinetics and tolerability in healthy adult subjects. Methods Two open-label, parallel-group, single-dose studies were conducted. Subjects received a single oral dose of saxagliptin 10 mg (Onglyza™). Results Compared with healthy subjects, the geometric mean area under the plasma concentration-time curve from time zero extrapolated to infinity (AUC ∞ ) for saxagliptin was 16%, 41% and 108% (2.1-fold) higher in subjects with mild, moderate or severe renal impairment, respectively. AUC ∞ values for 5-hydroxy saxagliptin were 67%, 192% (2.9-fold) and 347% (4.5-fold) higher in subjects with mild, moderate or severe renal impairment, respectively. As creatinine clearance (CL CR ) values decreased, saxagliptin and 5-hydroxy saxagliptin AUC ∞ generally increased or became more variable. Twenty-three percent of the saxagliptin dose (measured as the sum of saxagliptin and 5-hydroxy saxagliptin) was cleared by haemodialysis in a 4-hour dialysis session. In the hepatic impairment study, the differences in exposure to saxagliptin and 5-hydroxy saxagliptin were less than 2-fold across all groups. As compared with healthy subjects matched for age, bodyweight, sex and smoking status, the AUC ∞ values for saxagliptin were 10%, 38% and 77% higher in subjects with mild, moderate or severe hepatic impairment, respectively. These values were 22%, 7% and 33% lower, respectively, for 5-hydroxy saxagliptin compared with matched healthy subjects. Conclusions One-half the usual dose of saxagliptin 5mg (i.e. 2.5 mg orally once daily) is recommended for patients with moderate (CL CR 30–50 mL/min) or severe (CL CR <30 mL/min not on dialysis) renal impairment or ESRD, but no dose adjustment is recommended for those with mild renal impairment or any degree of hepatic impairment.

Many medicines, including several cholesterol-lowering agents (eg, lovastatin, simvastatin), antihypertensives (eg, diltiazem, nifedipine, verapamil), and antifungals (eg, ketoconazole) are metabolized by and/or inhibit the cytochrome P450 (CYP) 3A4 metabolic pathway. These types of medicines are commonly coprescribed to treat comorbidities in patients with type 2 diabetes mellitus (T2DM) and the potential for drug-drug interactions of these medicines with new medicines for T2DM must be carefully evaluated. To investigate the effects of CYP3A4 substrates or inhibitors, simvastatin (substrate), diltiazem (moderate inhibitor), and ketoconazole (strong inhibitor) on the pharmacokinetics and safety of saxagliptin, a CYP3A4/5 substrate; and the effects of saxagliptin on these agents in three separate studies. Healthy subjects were administered saxagliptin 10 mg or 100 mg. Simvastatin, diltiazem extended-release, and ketoconazole doses of 40 mg once daily, 360 mg once daily, and 200 mg twice daily, respectively, were used to determine two-way pharmacokinetic interactions. Coadministration of simvastatin, diltiazem extended-release, or ketoconazole increased mean area under the concentration-time curve values (AUC) of saxagliptin by 12%, 109%, and 145%, respectively, versus saxagliptin alone. Mean exposure (AUC) of the CYP3A4-generated active metabolite of saxagliptin, 5-hydroxy saxagliptin, decreased with coadministration of simvastatin, diltiazem, and ketoconazole by 2%, 34%, and 88%, respectively. All adverse events were considered mild or moderate in all three studies; there were no serious adverse events or deaths. Saxagliptin, when coadministered with simvastatin, diltiazem extended-release, or ketoconazole, was safe and generally well tolerated in healthy subjects. Clinically meaningful interactions of saxagliptin with simvastatin and diltiazem extended-release are not expected. The dose of saxagliptin does not need to be adjusted when coadministered with a substrate or moderate inhibitor of CYP3A4. A limitation to the lowest clinical dose of saxagliptin (2.5 mg) is proposed when it is coadministered with a potent CYP3A4 inhibitor such as ketoconazole.

Objectives: This study evaluated flexible-dose pharmacokinetics, safety, and effectiveness of aripiprazole in children and adolescents with conduct disorder (CD). Methods: This open-label, 15-day, three-center study with an optional 36-month extension enrolled a total of 23 patients: 12 children (6–12 years) and 11 adolescents (13–17 years) with CD and a score of 2–3 on the Rating of Aggression Against People and/or Property (RAAPP). Initially, the protocol used the following dosing: subjects <25 kg, 2 mg/day; subjects 25–50 kg, 5 mg/day; subjects >50–70 kg, 10 mg/day; and subjects >70 kg, 15 mg/day. Due to vomiting and sedation, this schedule was revised to: <25 kg, 1 mg/day; 25–50 kg, 2 mg/day; >50–70 kg, 5 mg/day; and >70 kg, 10 mg/day. Results: Aripiprazole pharmacokinetics were linear, and steady state appeared to be attained within 14 days. Both groups demonstrated improvements in RAAPP scores and Clinical Global Impressions–Severity (CGI-S) scores. Adverse events were similar to the known profile for aripiprazole in adults. Conclusion: The pharmacokinetics of aripiprazole in children and adolescents are linear and comparable with those in adults. Aripiprazole was generally well-tolerated in patients with CD, particularly after protocol adjustments, with improvements in aggressive behavior.

A major objective of antiretroviral therapy is to reduce the amount of human immunodeficiency virus type 1 (HIV-1) RNA in plasma to undetectable levels, because these levels appear to reflect the degree of viral replication in the body. Even low levels of replication may contribute to the emergence of resistant strains of HIV-1. Studies of highly active antiretroviral therapy have generally yielded less impressive results in HIV-infected children than in infected adults. In small studies of combinations that included a protease inhibitor in children who had previously been treated with nucleoside reverse-transcriptase inhibitors, plasma HIV-1 RNA levels decreased to undetectable . . .

In a search for genes that regulate circadian rhythms in mammals, the progeny of mice treated with N-ethyl-N-nitrosourea (ENU) were screened for circadian clock mutations. A semidominant mutation, Clock, that lengthens circadian period and abolishes persistence of rhythmicity was identified. Clock segregated as a single gene that mapped to the midportion of mouse chromosome 5, a region syntenic to human chromosome 4. The power of ENU mutagenesis combined with the ability to clone murine genes by map position provides a generally applicable approach to study complex behavior in mammals.

Mammalian circadian rhythms are regulated by a pacemaker within the suprachiasmatic nuclei (SCN) of the hypothalamus. The molecular mechanisms controlling the synchronization of the circadian pacemaker are unknown; however, immediate early gene (IEG) expression in the SCN is tightly correlated with entrainment of SCN-regulated rhythms. Antibodies were isolated that recognize the activated, phosphorylated form of the transcription factor cyclic adenosine monophosphate response element binding protein (CREB). Within minutes after exposure of hamsters to light, CREB in the SCN became phosphorylated on the transcriptional regulatory site, Ser$^{133}$. CREB phosphorylation was dependent on circadian time: CREB became phosphorylated only at times during the circadian cycle when light induced IEG expression and caused phase shifts of circadian rhythms. These results implicate CREB in neuronal signaling in the hypothalamus and suggest that circadian clock gating of light-regulated molecular responses in the SCN occurs upstream of phosphorylation of CREB.