Differential effects of isomers of clomiphene citrate on reproductive tissues in male mice.

OBJECTIVES: To determine, in a chronic dosing study, the oral toxicity potential of the test substances, enclomiphene citrate (ENC) and zuclomiphene citrate (ZUC), when administered to male mice by oral gavage. MATERIALS AND METHODS: Mice were divided into five treatment groups. Group I, placebo; Group II, 40 mg/kg body weight/day ENC; Group III, 4 mg/kg/day ENC; Group IV, 40 mg/kg/day ZUC; Group V, 4 mg/kg/day ZUC. Serum samples and tissues were obtained from each mouse for analysis and body weights were measured. RESULTS: In this chronic dosing study in mice, profound effects on Leydig cells, epididymis, seminal vesicles, and kidneys were seen, as well as effects on serum testosterone, follicle-stimulating hormone and luteinising hormone levels that were associated with ZUC treatment only. Treatment with the isolated enclomiphene isomer had positive effects on testosterone production and no effects on testicular histology. CONCLUSIONS: The present study suggests that an unopposed high dose of zuclomiphene can have pernicious effects on male mammalian reproductive organs. The deleterious effects seen when administering ZUC in male mice, justifies the case for a monoisomeric preparation and the development of ENC for clinical use in human males to increase serum levels of testosterone and maintain sperm counts.

Testosterone Restoration by Enclomiphene Citrate in Men with Secondary Hypogonadism: Pharmacodynamics and Pharmacokinetics.

OBJECTIVES: To determine the pharmacodynamic (PD) profile of serum total testosterone levels (TT) and luteinizing hormone (LH) in men with secondary hypogonadism following initial and chronic daily oral doses of enclomiphene citrate in comparison to transdermal testosterone. To determine the effects of daily oral doses of enclomiphene citrate (Androxal®) in comparison to transdermal testosterone on other hormones and markers in men with secondary hypogonadism. PATIENTS AND METHODS: This was a randomized, single blind, two-center phase II study to evaluate three different doses of enclomiphene citrate (6.25mg, 12.5mg and 25 mg Androxal®), versus AndroGel®, a transdermal testosterone, on 24-hour LH and TT in otherwise normal healthy men with secondary hypogonadism. Forty-eight men were enrolled in the trial (ITT Population), but 4 men had T levels >350 ng/dL at baseline. Forty-four men completed the study per protocol (PP population). All subjects enrolled in this trial had serum TT in the low range (<350 ng/dL) and had low to normal LH (<12 IU/L) on at least two occasions. TT and LH levels were assessed each hour for 24 hours to examine the effects at each of three treatment doses of enclomiphene versus a standard dose (5 grams) of transdermal testosterone (AndroGel). In the initial profile TT and LH were determined in a naïve population following a single initial oral or transdermal treatment (Day 1). This was contrasted to that seen after six weeks of continuous daily oral or transdermal treatment (Day 42). The pharmacokinetics of enclomiphene was performed in a select subpopulation. Serum samples were obtained over the course of the study to determine levels of various hormones and lipids. RESULTS: After six weeks of continuous use, the mean ± SD concentration of TT at Day 42 C0hrTT, was 604 ± 160 ng/dL for men taking the highest of dose of enclomiphene citrate (enclomiphene, 25 mg daily) and 500 ± 278 ng in those men treated with transdermal testosterone. These values were higher than Day 1 values but not different from each other (p = 0.23, T-test). All three doses of enclomiphene increased C0hrTT, CavgTT, CmaxTT, CminTT and CrangeTT. Transdermal testosterone also raised TT, albeit with more variability, and with suppressed LH levels. The patterns of TT over 24 hour period following six weeks of dosing could be fit to a non-linear function with morning elevations, mid-day troughs, and rising night-time levels. Enclomiphene and transdermal testosterone increased levels of TT within two weeks, but they had opposite effects on FSH and LH Treatment with enclomiphene did not significantly affect levels of TSH, ACTH, cortisol, lipids, or bone markers. Both transdermal testosterone and enclomiphene citrate decreased IGF-1 levels (p<0.05) but suppression was greater in the enclomiphene citrate groups. CONCLUSIONS: Enclomiphene citrate increased serum LH and TT; however, there was not a temporal association between the peak drug levels and the Cmax levels LH or TT. Enclomiphene citrate consistently increased serum TT into the normal range and increased LH and FSH above the normal range. The effects on LH and TT persisted for at least one week after stopping treatment.

Morbidity and mortality associated with renal insufficiency and endovascular repair of abdominal aortic aneurysms: a 5-year experience.

To evaluate the outcome of patients with renal insufficiency undergoing endovascular repair of abdominal aortic aneurysm (AAA), data were prospectively collected between 1998 and 2003 on patients undergoing elective repair of their AAA with a stent graft. The patients were divided into 2 groups: those with serum creatinine (Crs) concentrations <1.2 (Group A) and those with Crs > or =1.2 mg/dL not requiring hemodialysis (Group B). The outcomes of the procedure for these 2 groups were compared. Different variables that existed between the 2 groups and contributed to mortality included estimated blood loss (EBL), volume of contrast used in the operating room, incidence of diabetes (DM), tobacco use, and history of myocardial infarction (MI). In total, 213 patients underwent elective repair of their AAA with use of a stent graft: 61% who had a Crs <1.2 mg/dL (Group A) and 39% who had a Crs > or =1.2 mg/dL not requiring dialysis (Group B). Among 129 patients with normal renal function there was an 18.6% complication rate and 1.6% mortality rate. Of 83 patients with renal insufficiency not on hemodialysis 30.1% (Fisher's Exact Test = 0.076) had 1 or more complications and there was a 6% (Fisher's Exact Test = 0.166) mortality rate. One patient in Group A (0.8%) progressed to hemodialysis and 5 (6%) patients in Group B progressed to end-stage renal disease requiring hemodialysis (p=0.068). A statistically significant higher proportion of the patients in Group B had a history of MI (p<0.001). There was no difference in the amount of EBL between the 2 groups, but a significantly lower amount of contrast (p<0.05) was used in patients with renal insufficiency.

Population pharmacokinetics of telapristone (CDB-4124) and its active monodemethylated metabolite CDB-4453, with a mixture model for total clearance.

Telapristone is a selective progesterone antagonist that is being developed for the long-term treatment of symptoms associated with endometriosis and uterine fibroids. The population pharmacokinetics of telapristone (CDB-4124) and CDB-4453 was investigated using nonlinear mixed-effects modeling. Data from two clinical studies (n = 32) were included in the analysis. A two-compartment (parent) one compartment (metabolite) mixture model (with two populations for apparent clearance) with first-order absorption and elimination adequately described the pharmacokinetics of telapristone and CDB-4453. Telapristone was rapidly absorbed with an absorption rate constant (Ka) of 1.26 h(-1). Moderate renal impairment resulted in a 74% decrease in Ka. The population estimates for oral clearance (CL/F) for the two populations were 11.6 and 3.34 L/h, respectively, with 25% of the subjects being allocated to the high-clearance group. Apparent volume of distribution for the central compartment (V2/F) was 37.4 L, apparent inter-compartmental clearance (Q/F) was 21.9 L/h, and apparent peripheral volume of distribution for the parent (V4/F) was 120 L. The ratio of the fraction of telapristone converted to CDB-4453 to the distribution volume of CDB-4453 (Fmet(est)) was 0.20/L. Apparent volume of distribution of the metabolite compartment (V3/F) was fixed to 1 L and apparent clearance of the metabolite (CLM/F) was 2.43 L/h. A two-compartment parent-metabolite model adequately described the pharmacokinetics of telapristone and CDB-4453. The clearance of telapristone was separated into two populations and could be the result of metabolism via polymorphic CYP3A5.