Modeling follicle stimulating hormone levels in serum for controlled ovarian hyperstimulation iii: Improved gonadotropin administration

Background: A numerical model with two pharmacokinetic parameters (the rate of diffusion into the blood (τ _in) and the rate of disappearance from the blood (τ _out)) mimicks the slow changes of follicle stimulating hormone (FSH) seen in serum. It is often desired to change serum FSH levels more rapidly. Since the pharmacokinetic parameters cannot be changed in patients, we used the model to investigate changing the amount and timing of gonadotropin administration to change FSH levels in serum more rapidly. Methods: Parameters defining the model were obtained as described previously [1]. The doses administered, and the timing of administration were individually specified. Results: The rise of serum FSH was made more rapid by administering an initial injection larger than the subsequent injections. When a rapid decrease of serum FSH was desired, administration of the new, lower dose was delayed. Conclusion: Use of a model that simulates the serum levels of FSH during gonadotropin administration provided a framework for learning how to achieve the desired serum FSH levels more rapidly in patients. With knowledge of a particular patient's τ _in and τ _out, optimal FSH administration for that patient can be determined through modeling.