Testosterone and Gonadotrophin Profiles in Patients on Daily or Monthly LHRH Analogue ICI 118630 (Zoladex) Compared with Orchiectomy

Abstract

Diurnal profiles of circulating gonadotrophins and testosterone have been measured in patients with prostatic carcinoma on long-term treatment with the LHRH agonist analogue ICI 118630, which was administered either by subcutaneous daily injection or monthly injection of the depot preparation. These have been compared with profiles in patients who had undergone orchiectomy. Daily injection of the analogue induced a significant rise in the level of LH but this was not associated with a significant rise in circulating testosterone. There was no diurnal variation of LH or testosterone concentration in patients receiving the depot preparation and this did not differ in patients who were "mid-cycle" compared with those who were "end-cycle". The depot preparation did, however, induce significantly lower circulating levels of testosterone than did daily injection of the analogue and the levels were comparable with those achieved after orchiectomy.

Time course of serum testosterone and luteinizing hormone levels after cessation of long‐term luteinizing hormone‐releasing hormone agonist treatment in patients with prostate cancer

“…There are some reports of T level recovery after relatively short-term (less than 1 year on average) LH-RH agonist therapy [3][4][5][6][7][8][9]. Nejat et al [7] reported that T level recovery did not differ between 24 patients who received therapy for less than 4 months and 44 patients who received it for 4 months or longer.…”

“…In several studies, the serum luteinizing hormone (LH) or testosterone (T) levels rose gradually after extending the administration interval of a 1-month depot of LH-RH agonist from 4 to 6 weeks [5,6]. The authors of these studies have therefore insisted that the administration period needs to be strictly complied with to keep the T levels within the castrated level.…”

“…However, to our knowledge, the time course of recovery of LH or testosterone T levels after LH-RH agonist therapy cessation has been the focus of only a few small or short-term studies [5][6][7][8][9][10][11]. We undertook the present study to examine the recovery in serum LH and T levels following LH-RH agonist therapy cessation in patients with prostate cancer who received LH-RH agonist therapy for a minimum of 2 years as an adjuvant therapy for radical prostatectomy or external beam radiotherapy.…”

Endocrine effects, efficacy and tolerability of a 10.8‐mg depot formulation of goserelin acetate administered every 13 weeks to patients with advanced prostate cancer

“…As the matrix biodegrades, goserelin is released into the subcutaneous tissue and absorbed into the systemic circulation. Studies revealed high rates of maintaining testosterone suppression (92–100%) when the dosing interval of Zoladex 3.6 mg was extended from 4 to 5 weeks [ 3, 4]. Modification of the copolymer carrier allowed for the development of a 10.8‐mg, 3‐month Zoladex depot [ 5].…”

Pharmacology of the Luteinising Hormone-Releasing Hormone (LHRH) Analogue, Zoladex

“…(It should be noted that recovery of testicular function occurred around 40 days after the final depot was administered.) This advan tage of depot Zoladex has also been observed in the clinic where incomplete pituitary desensitisation is seen in some patients given daily s.c. injections of the drug, in contrast to complete pituitary desensitisation in those given Zoladex depot [19]. …”