title: Evaluation of the relationship between plasma concentrations of en- and zuclomiphene and induction of ovulation in anovulatory women being treated with clomiphene citrate.
abstract: OBJECTIVE
  To investigate the relationship between the plasma concentrations of clomiphene citrate (CC) isomers zu- (Zu) and enclomiphene (En), and ovulation outcome.
  
  
  METHODS
  Prospective, cohort study.
  
  
  METHODS
  Reproductive medicine and fertility center in a university teaching hospital, United Kingdom.
  
  
  METHODS
  Forty-two women with World Health Organization type 2 infertility.
  
  
  METHODS
  The clinical and biochemical features of patients who were about to start CC for induction of ovulation were recorded. Plasma concentration of Zu and En were monitored at three points (days 2, 8, and 21) throughout the treatment cycle(s).
  
  
  METHODS
  Ovulation.
  
  
  RESULTS
  Thirty-nine patients completed the study. Both En and Zu accumulated throughout treatment. Among the 36 responders, there was no statistically significant relationship between the clinical and biochemical characteristics of the patients, En or Zu concentrations, and the dose required to induce ovulation. Moreover, the Zu and En concentrations were not different in the three patients who failed to respond.
  
  
  CONCLUSIONS
  The concentrations of En and Zu in plasma, on their own or in combination with other covariates (e.g., weight, body mass index, free androgen index), are not a predictor of the ovulation response to CC or of the dose requirement. Further studies are needed to explore the role of additional covariates, including the presence of active metabolites, and the balance of the effects of En and Zu.
authors: Academic Unit of Clinical Pharmacology, University of Sheffield, Sheffield, United Kingdom.
authors: Cyrus
authors: C
authors: Ghobadi
authors: Saad
authors: S
authors: Amer
authors: Hany
authors: H
authors: Lashen
authors: Martin S
authors: MS
authors: Lennard
authors: William L
authors: WL
authors: Ledger
authors: Amin
authors: A
authors: Rostami-Hodjegan
mesh_terms: D000328:Adult; D000858:Anovulation / Q000097:blood* / Q000188:drug therapy*; D015992:Body Mass Index; D002996:Clomiphene / Q000097:blood* / Q000627:therapeutic use*; D064695:Enclomiphene; D005260:Female; D005300:Fertility Agents, Female / Q000097:blood / Q000627:therapeutic use; D006801:Humans; D010060:Ovulation / Q000187:drug effects; D010062:Ovulation Induction / Q000379:methods*; D012372:ROC Curve; D013997:Time Factors; D055815:Young Adult
chemical_list: D005300:Fertility Agents, Female; D002996:Clomiphene; D064695:Enclomiphene