McKenna's Pharmacology for Nursing, 2e

607

C H A P T E R 4 0 Drugs affecting the female reproductive system

T he female reproductive system functions in a cyclical fashion, not in the steady-state fashion seen with much of the rest of the endocrine system. Altering any compon­ ent of this cycle or the system can have a wide variety of effects on the entire body. Drugs that affect the female reproductive system typically include hormones and hormonal-like agents. Figure 40.1 reviews the female reproductive system and sites of action of the drugs used to affect the system. Box 40.1 highlights considerations related to the use of drugs discussed in this chapter as they affect the female reproductive system throughout the lifespan.

mechanisms of the endocrine system to decrease the release of endogenous hormones. Drugs that act like oestrogen, particularly at specific oestrogen receptors, are also used to stimulate the effects of oestrogen in the body with fewer of the adverse effects. See Table 40.1 for information on these agents. S ex hormones Female sex hormones include oestrogens and the proges- togens (the endogenous female hormone progesterone and its various derivatives). Oestrogens that are availa- ble for use include oestradiol ( Estraderm , Climara and others) and conjugated oestrogens ( Premarin ). Progestogens include desogestrel ( Marvelon ), dros- pirenone ( Yasmin , YAZ ), etonogestrel ( Implanon ), levonorgestrel ( Microlut , Mirena ), medroxyprogester- one ( Provera ), and nomegestrol ( Zoely ), norethisterone ( Brevinor ) and progesterone ( Crinone, Pro-Feme ).

SEX HORMONES AND OESTROGEN RECEPTOR MODULATORS

The female sex hormones can be used to replace hormones that are missing or to act on the control

Fertility drugs: ganirelix, cetrorelix and lutropin work here

Fertility drugs: clomiphene, follitropins, chorionogonadotropin alfa work here

Hypothalamus

GnRH

Prostaglandins: gemeprost, dinoprostone work here

FSH/LH

Pituitary

Primary follicle

Mature follicle

Ovary

Fallopian tube

Oral contraceptives work here

Ovary

Oxytocics: ergometrine and oxytocin work here

Corpus albicans

Corpus albicans

Ovum

Uterus

Progesterone

Oestrogens: oestradiol and oestrogens work here

Rectum Bladder

Progestins: desogestrol, drospirenone, levonorgestrel, medroxy- progesterone and progesterone work here

Vagina

Labia

Raloxifene and toremifene work here

Oestrogen receptors

bone resorption

FIGURE 40.1  Sites of action of drugs affecting the female reproductive system.