Search

ABSTRACT: Introduction: Oral submucous fibrosis (OSMF), a chronic debilitating condition of the mouth, has been treated both surgically and non-surgically, but non-surgical methods yield inconsistent results. The surgical methods essentially comprise of bilateral sectioning of fibrous bands with or without coronoidectomy followed by covering of the surgical defect with a graft or a wound dressing material such as collagen sheet. Materials and Methods: This study comprised 30 clinically diagnosed cases of OSMF. This study compared transposition of buccal pad fat graft with collagen sheet to cover the defect within the following parameters: pain, swelling, mouth opening, color of mucosa, palpability of fibrous bands, and suppleness of mucosa. Results: We found significant difference in the postoperative mouth opening, an insignificant difference for post surgical morbidity and higher grades of surgical convenience in using collagen sheet as a wound dressing material. Conclusion: Collagen membrane is a superior method compared to transposition of the buccal pad of fat as a graft to cover the surgical wound in the treatment of OSMF of grade III and above.

ABSTRACT: Introduction: Bone grafts are frequently used for the treatment of bone defects, but can cause postoperative complications, and sometimes a sufficient quantity of bone is not available. Hence, synthetic biomaterials have been used as an alternative to autogenous bone grafts. Recent clinical reports suggest that application of autologous blood plasma enriched with platelets can enhance the formation of new bone. There are very few in vitro or in vivo studies published on the efficiency of platelet-rich plasma (PRP). The objective of this study was to evaluate the alloplastic bone substitute for its osteogenic potential with or without PRP. Materials and Methods: Twenty-three patients with periapical bony defects were selected for this study. Clinical parameters such as pain visual analog scale (VAS), swelling, infection, graft migration, rejection, radiographical interpretations at regular interval and scintigraphic evaluation were done to evaluate osteogenic potential of alloplastic bone substitute with or without PRP. Results: The highest acceleration in bone formation was observed in groups where alloplastic bone substitute was used with PRP. There were no statistically significant differences between the two groups regarding other outcome variables throughout the postoperative period. Conclusion: Addition of PRP significantly accelerates vascularization of the graft, improves soft tissue healing, reduces postoperative morbidity and enhances bone regeneration.

Aims: To compare, in an open-label, randomized, crossover phase II substudy, the glucodynamics of insulin glargine and those of basal insulin peglispro (BIL) in patients with type 1 diabetes., Methods: Patients (n = 23) underwent 24-h euglycaemic clamps after 8 weeks of treatment with glargine or with BIL. Clinically-titrated basal insulin doses (BIL group 16-64 U; glargine group 19-60 U) were administered on the morning of the clamp., Results: At baseline, the patients' mean ± standard deviation (s.d.) body mass index was 26.78 ± 4.20 kg/m 2 and glycated haemoglobin was 7.69 ± 0.99%. The mean ± s.d. endpoint dose for the BIL group was 0.42 ± 0.13 U/kg and for the glargine group was 0.42 ± 0.10. The daily mean ± s.d. blood glucose concentration was 7.7 ± 1.2 in the BIL group and 7.9 ± 1.2 mmol/l in the glargine group (p = 0.641). The mean ± s.d. total and nocturnal hypoglycaemia rates/30 days were 2.7 ± 2.3 and 0.5 ± 0.8, respectively, for the BIL group, and 3.0 ± 2.4 and 0.7 ± 1.1, respectively, for the glargine group (p = 0.112 and 0.428). The mean glucose infusion rate (GIR) normalized to insulin unit was lower for BIL than for glargine. One patient in the glargine group and eight patients in the BIL group had minimal (<0.8 g/kg) GIRs over 24 h. The mean ± s.d. total glucose infused over 24 h (G TOT (0-24) ) was 1.22 ± 0.82 g/kg in the BIL group and 1.90 ± 1.01 g/kg in the glargine group (p = 0.002). The mean ± s.d. total glucose infused during hours 0-6 (G TOT (0-6) ) was 0.21 ± 0.22 in the BIL group and 0.41 ± 0.22 g/kg in the glargine group (p < 0.001), while the mean total glucose infused during hours 18-24 (G TOT (18-24) ) in the BIL group was 0.28 ± 0.18 g/kg and in the glargine group was 0.35 ± 0.23 g/kg (p = 0.198). The peak-to-trough ratio was 1.41 for BIL versus 2.22 for glargine., Conclusions: BIL has a flatter profile than glargine, with potentially more stable metabolic control. The lower G TOT (0-24) observed in the BIL group is consistent with BIL's reduced peripheral action., (© 2016 John Wiley & Sons Ltd.)

Aims: Basal insulin peglispro (BIL), a novel PEGylated basal insulin with a large hydrodynamic size, has a delayed absorption and reduced clearance that prolongs the duration of action. The current study compared the effects of BIL and insulin glargine (GL) on endogenous glucose production (EGP), glucose disposal rate (GDR) and lipolysis in patients with type 1 diabetes., Materials and Methods: This was a randomized, open-label, four-period, crossover study. Patients received intravenous infusions of BIL and GL, each at two dose levels selected for partial and maximal suppression of EGP, during an 8 to 10 h euglycemic clamp procedure with d-[3- 3 H] glucose., Results: Following correction for equivalent human insulin concentrations (EHIC), low-dose GL infusion resulted in similar EGP at the end of the clamp compared to low-dose BIL infusion (GL/BIL ratio of 1.03) but a higher GDR (GL/BIL ratio of 2.42), indicating similar hepatic activity but attenuated peripheral activity of BIL. Consistent with this, the EHIC-corrected GDR/EGP at the end of the clamp was 1.72-fold greater for GL than BIL following low-dose administration. At the lower dose of BIL and GL (concentrations in the therapeutic range), BIL produced less suppression of lipolysis compared with GL as indicated by free fatty acid and glycerol levels at the end of the clamp., Conclusions: Compared with GL, BIL restored the hepato-peripheral insulin action gradient seen in normal physiology via its peripherally restricted action on target tissues related to carbohydrate and lipid metabolism., (© 2016 John Wiley & Sons Ltd.)

The pharmacokinetics of LY2605541 (basal insulin peglispro), a novel long-acting basal insulin analogue, was evaluated in 5 groups of subjects with varying degrees of renal function based on creatinine clearance: normal renal function (>80 mL/min), mild renal impairment (51-80 mL/min), moderate renal impairment (30-50 mL/min), severe renal impairment (<30 mL/min), or end-stage renal disease (ESRD) requiring hemodialysis. Serial blood samples for pharmacokinetic analyses were collected up to 12 days following a single 0.33 U/kg subcutaneous dose of LY2605541. The apparent clearance (CL/F) and half-life across groups were not affected by renal function. Cmax values were lower in subjects with increasing severity of renal impairment; however, the small decrease in Cmax did not affect the overall exposure. Regression analysis showed that LY2605541 clearance is independent of renal function (slope = 0.000863; P = .885). The mean fraction of LY2605541 eliminated by a single hemodialysis session was 13% in subjects with ESRD. LY2605541 was generally well tolerated in healthy subjects and those with renal impairment following a single 0.33 U/kg subcutaneous dose. Given these data, no dose adjustment of LY2605541 based on pharmacokinetics is recommended in renal impairment or in patients undergoing hemodialysis., (© 2016, The Authors. Clinical Pharmacology in Drug Development Published by Wiley Periodicals, Inc. on behalf of The American College of Clinical Pharmacology.)

Objective: We evaluated the endogenous glucose production (EGP) and glucose disposal rate (GDR) over a range of doses of basal insulin peglispro (BIL) and insulin glargine in healthy subjects., Research Design and Methods: This was a single-center, randomized, open-label, four-period, incomplete-block, crossover study conducted in eight healthy male subjects. Subjects had 8-h euglycemic clamps performed with primed, continuous infusions of BIL (5.1 to 74.1 mU/min) in three dosing periods and insulin glargine (20 or 30 mU/m(2)/min) in a fourth period, targeted to achieve 50-100% suppression of EGP. D-[3-(3)H] glucose was infused to assess rates of glucose appearance and disappearance., Results: Mean BIL and insulin glargine concentrations (targeted to reflect the differences in intrinsic affinities of the two basal insulins) ranged from 824 to 11,400 and 212 to 290 pmol/L, respectively, and increased accordingly with increases in dose. Suppression of EGP and stimulation of GDR were observed with increasing concentrations of both insulins. At insulin concentrations where EGP was significantly suppressed, insulin glargine resulted in increased GDR. In contrast, at comparable suppression of EGP, BIL had minimal effect on GDR at lower doses and had substantially less effect on GDR than insulin glargine at higher doses., Conclusions: The novel basal insulin analog BIL has relative hepatopreferential action and decreased peripheral action, compared with insulin glargine, in healthy subjects., (© 2014 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.)

LY2605541 is a novel basal insulin analog with a prolonged duration of action. Two Phase I studies assessed LY2605541 pharmacokinetics (PK), glucodynamics (GD), and tolerability in healthy subjects. In Study 1, 33 subjects received single subcutaneous (SC) doses of LY2605541 (0.01-2.22 U/kg) and insulin glargine (0.5-0.8 U/kg) followed by euglycemic clamp for up to 24-36 hours. In Study 2, absolute bioavailability of SC LY2605541 was assessed in 8 subjects by comparing dose normalized area under concentration versus time curve of SC against IV administration. Time-to-maximum plasma concentration (medians) and geometric means for half-life (t½ ) and apparent clearance, respectively, ranged from 18.0 to 42.0 hours, 24.4-45.5 hours, and 1.8-2.8 L/h for SC LY2605541, versus 10.0-12.0 hours, 12.2-14.9 hours, and 51.4-65.2 L/h for SC insulin glargine. LY2605541 glucose infusion rate (GIR) profiles were sustained for ≥36 hours versus glargine GIR profiles, which waned at 24 hours. After IV administration, LY2605541's geometric mean t½ was 2.3 hours. LY2605541 intra-subject variability (CV%) was <18% for PK and <32% for GD parameters. The most common adverse events were related to study procedures and were mild-moderate in severity. These results established a well-tolerated baseline dose for LY2605541 with a relatively flat PK profile and low intra-subject variability., (© 2014, The American College of Clinical Pharmacology.)

Aims: To assess the pharmacokinetics (PK) and glucodynamics (GD) of LY2605541 in patients with type 2 diabetes mellitus., Methods: This parallel-group, open-label, dose-escalation study examined the PK and GD of basal insulin LY2605541 after single and multiple-dose administration. Fixed doses of LY2605541 (0.33-1.00 U/kg) were given once-daily (QD) for 14 days to insulin-treated patients with type 2 diabetes. A 24-h euglycaemic glucose clamp was conducted on days 1 and 14., Results: PK steady state was achieved within 7-10 days and the peak-to-trough fluctuation was <2, translating to a nearly 'peakless' glucose infusion rate at steady state and with a duration of action of at least 24 h. Across dose levels t1/2 ranged from 44.7 to 75.5 h (~2-3 days). As steady state was achieved, there were dose-dependent reductions in the prandial insulin dose and in fasting blood glucose, which decreased to 60-100 mg/dl across dose levels. Within-patient variability was <14 and <26% for the area under the concentration versus time curve (AUC) of the 8-point blood glucose profile and fasting blood glucose, respectively. The nocturnal glucose control between 03:00 and 09:00 hours was relatively unchanged. Mild hypoglycaemia was the most common adverse event., Conclusions: In this Phase I study of fixed LY2605541 doses without titration, LY2605541 was well-tolerated and demonstrated a flat PK and GD profile accompanied by glucose normalization, prandial insulin dose reduction and no severe hypoglycaemia., (© 2013 John Wiley & Sons Ltd.)

The impact of the novel basal insulin LY2605541 (LY) on hepatic and nonhepatic glucose uptake (non-HGU) was evaluated. Conscious dogs underwent euglycemic clamps with tracer and hepatic balance measurements. Clamp period infusions were peripheral venous regular insulin (0.1 nmol ⋅ kg(-1) ⋅ h(-1) [control], n = 6) or LY (bolus [nmol/kg], continuous [nmol ⋅ kg(-1) ⋅ h(-1)]: 0.5, 0.5 [n = 6]; 0.375, 0.375 [n = 5]; 0.25, 0.25 [n = 4]), somatostatin, and glucose, as well as intraportal glucagon (basal). During the clamp, the dogs switched from net hepatic glucose output to uptake (rates reached 2.1 ± 1.2, 0.9 ± 2.1, 8.6 ± 2.3, and 6.0 ± 1.1 µmol ⋅ kg(-1) ⋅ min(-1) within 5 h in control, LY0.25, LY0.375, and LY0.5, respectively). Non-HGU in LY increased less than in control; the ratio of change from basal in non-HGU to change in net hepatic glucose balance, calculated when glucose infusion rates (GIRs) were ~20 µmol ⋅ kg(-1) ⋅ min(-1) in all groups, was higher in control (1.17 ± 0.38) versus LY0.25 (0.39 ± 0.33), LY0.375 (-0.01 ± 0.13), and LY0.5 (-0.09 ± 0.07). Likewise, the change from baseline in glucose Rd-to-Ra ratio was greatest in control (1.4 ± 0.3 vs. 0.6 ± 0.4, 0.5 ± 0.2, and 0.6 ± 0.2 in LY0.25, LY0.375, and LY0.5, respectively). In contrast to exogenously administered human insulin, LY demonstrated preferential hepatic effects, similar to endogenously secreted insulin. Therefore, the analog might reduce complications associated with current insulin therapy.

Aim: To evaluate the effectiveness of coronoidectomy in advanced (stage III-IV) oral submucous fibrosis (OSMF) and temporomandibular joint (TMJ) ankylosis., Materials and Methods: Five patients clinically diagnosed as grade III/IV OSMF (group 1) and seven patients clinically and radiographically confirmed as TMJ ankylosis (group 2) underwent surgery entailing coronoidectomy in addition to conventional surgical procedures required in both the conditions followed by vigorous mouth opening exercises. The results were evaluated using the interincisal distance at maximum mouth opening as the objective outcome over a follow-up period of 2 months., Results: OSMF patients (group I) showed a mean preoperative interincisal opening of 14.40 mm which increased to 24.60 mm after conventional procedures and showed further increment to 35 and 44.80 mm after unilateral and bilateral coronoidectomy, respectively; which was statistically significant (P = 0.043). Follow-up of 2 months showed a gradual increase in mean mouth opening compared to baseline which was also found to be statistically significant (P = 0.043). In TMJ ankylosis patients (group II), preoperative mean mouth opening of 6.71 mm increased to 24.29 mm after conventional procedures, and further to 37.29 mm after unilateral coronoidectomy which was statistically significant (P = 0.018). On subsequent follow-up of 2 months, a gradual increase in mean mouth opening compared to baseline was observed which was statistically significant (P = 0.018)., Conclusion: Coronoidectomy is an effective adjunct in increasing intraoperative and stabilizing postoperative mouth opening.

Aim: The purpose of this study was to determine and compare various postoperative parameters like ease of operability, plate adaptability, stability etc., associated with use of matrix miniplate versus locking miniplate in the treatment of displaced mandibular angle fractures., Materials and Methods: The study was carried out in the Department of Oral and Maxillofacial surgery, King George's Medical College, GM and Associated Hospital, Lucknow. Total 50 patients were treated and included in the study. These were divided into two groups of 25 each and were treated with two of the standard techniques, i.e., one is matrix miniplate osteosynthesis and other is locking miniplate osteosynthesis. These patients were evaluated for postoperative complications and the differences between the two Groups were assessed., Results: Patients treated by matrix miniplate showed better recovery phase postoperatively as compared to locking miniplate group., Conclusion: Based on this study matrix mini plate osteosynthesis may be considered as the better alternative method available for the treatment of displaced mandibular angle fractures.

OBJECTIVE To compare effects of LY2605541 versus insulin glargine on daily mean blood glucose as part of a basal-bolus regimen for type 1 diabetes. RESEARCH DESIGN AND METHODS In this randomized, Phase 2, open-label, 2 × 2 crossover study, 137 patients received once-daily basal insulin (LY2605541 or glargine) plus mealtime insulin for 8 weeks, followed by crossover treatment for 8 weeks. Daily mean blood glucose was obtained from 8-point self-monitored blood glucose profiles. The noninferiority margin was 10.8 mg/dL. RESULTS LY2605541 met noninferiority and superiority criteria compared with insulin glargine in daily mean blood glucose (144.2 vs. 151.7 mg/dL, least squares mean difference = -9.9 mg/dL [90% CI -14.6 to -5.2], P < 0.001). Fasting blood glucose variability and A1C were reduced with LY2605541 compared with insulin glargine (both P < 0.001). Mealtime insulin dose decreased with LY2605541 and increased with insulin glargine. Mean weight decreased 1.2 kg with LY2605541 and increased 0.7 kg with insulin glargine (P < 0.001). The total hypoglycemia rate was higher for LY2605541 (P = 0.04) and the nocturnal hypoglycemia rate was lower (P = 0.01), compared with insulin glargine. Adverse events (including severe hypoglycemia) were similar, although more gastrointestinal-related events occurred with LY2605541 (15% vs. 4%, P < 0.001). Mean changes (all within normal range) were higher for alanine aminotransferase, aspartate aminotransferase, triglycerides, and LDL-cholesterol and lower for HDL-cholesterol with LY2605541 compared with insulin glargine (all P < 0.02). CONCLUSIONS In type 1 diabetes, compared with insulin glargine, LY2605541, a novel, long-acting basal insulin, demonstrated greater improvements in glycemic control, increased total hypoglycemia, and reduced nocturnal hypoglycemia, as well as reduced weight and lowered mealtime insulin doses.

A proof of concept study was conducted to investigate the safety and tolerability of a novel oral glucokinase activator, LY2599506, during multiple dose administration to healthy volunteers and subjects with Type 2 diabetes mellitus (T2DM). To analyze the study data, a previously established semi-mechanistic integrated glucose-insulin model was extended to include characterization of glucagon dynamics. The model captured endogenous glucose and insulin dynamics, including the amplifying effects of glucose on insulin production and of insulin on glucose elimination, as well as the inhibitory influence of glucose and insulin on hepatic glucose production. The hepatic glucose production in the model was increased by glucagon and glucagon production was inhibited by elevated glucose concentrations. The contribution of exogenous factors to glycemic response, such as ingestion of carbohydrates in meals, was also included in the model. The effect of LY2599506 on glucose homeostasis in subjects with T2DM was investigated by linking a one-compartment, pharmacokinetic model to the semi-mechanistic, integrated glucose-insulin-glucagon system. Drug effects were included on pancreatic insulin secretion and hepatic glucose production. The relationships between LY2599506, glucose, insulin, and glucagon concentrations were described quantitatively and consequently, the improved understanding of the drug-response system could be used to support further clinical study planning during drug development, such as dose selection.

Objective: To evaluate whether LY2605541 results in lower fasting blood glucose (FBG) versus insulin glargine (GL)., Research Design and Methods: This 12-week, randomized, open-label, Phase 2 study enrolled patients with type 2 diabetes (hemoglobin A(1c) [A1C] ≤ 10.5%), taking metformin and/or sulfonylurea with GL or NPH insulin once daily. Patients converted to morning insulin administration during lead-in were randomized 2:1 from GL (n = 248) or NPH insulin (n = 39) to LY2605541 (n = 195) or GL (n = 95) once daily in the morning., Results: At 12 weeks, FBG (mean ± SE) was similar with LY2605541 and GL (118.2 ± 2.0 mg/dL [6.6 ± 0.1 mmol/L] vs. 116.9 ± 2.7 mg/dL [6.5 ± 0.2 mmol/L], P = 0.433) as was A1C (7.0 ± 0.1 vs. 7.2 ± 0.1%, P = 0.279). Intraday blood glucose variability was reduced with LY2605541 (34.4 vs. 39.1 mg/dL [1.9 vs. 2.2 mmol/L], P = 0.031). LY2605541 patients had weight loss (-0.6 ± 0.2 kg, P = 0.007), whereas GL patients gained weight (0.3 ± 0.2 kg, P = 0.662; treatment difference: -0.8 kg, P = 0.001). The incidence and rate of both total hypoglycemia and nocturnal hypoglycemia were comparable between LY2605541 and GL, although, LY2605541 had a 48% reduction in nocturnal hypoglycemia after adjusting for baseline hypoglycemia (P = 0.021). Adverse events were similar across treatments. Alanine aminotransferase and aspartate aminotransferase remained within normal range but were significantly higher with LY2605541 (P ≤ 0.001)., Conclusions: In patients with type 2 diabetes, LY2605541 and GL had comparable glucose control and total hypoglycemia rates, but LY2605541 showed reduced intraday variability, lower nocturnal hypoglycemia, and weight loss relative to GL.

Mandible is the second most common facial fracture. There has been a significant increase in the number of cases in recent years with the advent of fast moving automobiles. Mandibular fractures constitute a substantial proportion of maxillofacial trauma cases in Lucknow. This study was undertaken to study mandibular fractures clinicoradiologically with an aim to calculate incidence and study pattern and the commonest site of fractures in population in and around Lucknow. Patient presenting with history of trauma at various centers of maxillofacial surgery in and around Lucknow were included in this study. Detailed case history was recorded followed by thorough clinical examination, and radiological interpretation was done for establishing the diagnosis and the data obtained was analyzed statistically. Out of 66 patients with mandibular fractures, highest percentage was found in 21-30 years of age with male predominance. Road traffic accidents were the most common cause of fracture with parasymphysis being commonest site. Commonest combination was parasymphysis with subcondyle. There was no gender bias in etiology with number of fracture sites. The incidence and causes of mandibular fracture reflect trauma patterns within the community and can provide a guide to the design of programs geared toward prevention and treatment.

The complexity of structure and functions of the Temporomandibular Joint (TMJ) make the diagnosis of its diseases/disorders difficult. Remarkable progress made in the field of imaging of this joint led us to compare four imaging modalities viz. plain radiographs, CT scan, MRI and ultrasound. We found that MRI was most specific and sensitive for interpretation of soft tissue and inflammatory conditions in the joint, whereas CT examination produced excellent image for osseous morphology and pathology. Plain X-rays are useful for destructive bony changes and sonography is a good in aid in diagnosing disc derangement and is very economical.

Aims: To develop a population pharmacokinetic model to describe the pharmacokinetics of desipramine in healthy subjects, after oral administration of a 50mg dose. Additional objectives were to develop a semi-mechanistic population pharmacokinetic model for desipramine, which allowed simulation of CYP2D6-mediated inhibition, when using desipramine as a probe substrate, and to evaluate certain study design elements, such as duration of desipramine pharmacokinetic sampling, required sample size and optimal pharmacokinetic sampling schedule for intermediate, extensive and ultrarapid metabolizers of CYP2D6 substrates., Results: The mean population estimates of the first order absorption rate constant (k(a) ), apparent clearance (CL/F) and apparent volume of distribution at steady state (V(ss) /F) were 0.15h(-1) , 111 lh(-1) and 2950 l, respectively. Further, using the proposed semi-mechanistic hepatic intrinsic clearance model with Bayesian inference, mean population desipramine hepatic intrinsic clearance was estimated to be 262 lh(-1) with between-subject variability of 84%. d-optimal PK sampling times for intermediate metabolizers were calculated to be approximately 0.25, 24, 75 and 200h. Similar sampling times were found for ultrarapid and extensive metabolizers except that the second d-optimal sample was earlier at 14 and 19h, respectively, compared with 24h for intermediate metabolizers. This difference in sampling times between the three genotypes can be attributed to the different intrinsic clearances and elimination rates., Conclusions: A two compartment population pharmacokinetic model best described desipramine disposition. The semi-mechanistic population model developed is suitable to describe the pharmacokinetic behaviour of desipramine for the dose routinely used in drug-drug interaction (DDI) studies. Based on this meta-analysis of seven trials, a sample size of 21 subjects in cross-over design is appropriate for assessing CYP2D6 interaction with novel compounds., (© 2010 The Authors. British Journal of Clinical Pharmacology © 2010 The British Pharmacological Society.)

The safety, tolerability, and pharmacokinetics of orally administered enzastaurin were evaluated in 2 placebo-controlled, dose escalation studies in healthy subjects. In the first human dose study, single doses (2-400 mg) were evaluated, with 22 subjects receiving enzastaurin. The mean half-lives of enzastaurin and its metabolites ranged from approximately 12 to 40 hours. The longer half-life of the major circulating and pharmacologically active metabolite allowed once-a-day dosing and predicted that steady state would be achieved within 2 weeks of daily oral dosing in all subjects. In the multiple-dose study, daily doses (25-400 mg) were examined, with 24 subjects receiving at least 1 dose. The most common adverse events related to enzastaurin were headache, sleepiness, diarrhea, and nausea. No clinically significant changes in QTc intervals were observed. Overall, enzastaurin was well tolerated in healthy subjects, and the planned maximum dose was achieved in both studies.

Alamifovir, a purine nucleotide analogue prodrug, and its hydrolyzed derivatives have shown preclinical efficacy activity against wild-type and lamivudine-resistant hepatitis B virus. Two studies were conducted to examine the single- and multiple-dose alamifovir pharmacokinetics after oral administration in healthy males. In study 1, subjects were given single doses (0.2 to 80 mg), with a subset receiving 20 mg in a fed state. Study 2 subjects were dosed with 2.5 to 15 mg twice daily for 15 days. Plasma samples were collected over 72 h in study 1 and over 24 h on days 1 and 15 in study 2. Concentrations of alamifovir and its major metabolites were determined using liquid chromatography/tandem mass spectrometry methods. The data were analyzed using a noncompartmental technique. Although alamifovir was rapidly absorbed, there was limited systemic exposure due to its rapid hydrolysis and formation of at least three metabolites, suggesting that alamifovir acts as a prodrug. The major metabolites detected were 602074 and 602076, with 602075 detectable only in higher-dose groups. Maximum 602074 plasma concentration was achieved at approximately 0.5 h (T(max)) and declined with a 1- to 2-h terminal half-life (t(1/2)). Maximum concentrations of 602076 (C(max)) averaged 10% of the 602074 C(max) and reached T(max) in 2.5 h with a 4-h t(1/2). Food appeared to decrease the extent of absorption of the compound. Multiple dosing resulted in minimal accumulation, and the concentrations following multiple doses could be predicted using the single-dose data. Alamifovir was well tolerated and the pharmacokinetics were characterized in these studies.