Medications Used Commonly in Fertility Treatments for female.
For ovulation induction
Clomiphene Citrate (Clomid) is a compound that is very similar in structure to estrogen. Because of this likeness, Clomid is able to bind to estrogen receptors in the hypothalamus (a part of the brain that regulates ovulation). This prevents the brain from seeing the negative signal from estrogen that is being released by the ovaries. As a result, the hypothalamus continues to stimulate the pituitary gland to make FSH and LH. These hormones stimulate follicular growth in the ovary.
Clomiphene citrate is administered orally in 50 mg increments (50, 100, 150) over 5 days. There are 2 common regimens for administration. Using the first day of menses as cycle day 1, Clomid is taken on days 3-7 or days 5-9. If follicular monitoring is used, an ultrasound is usually done on day 10 (if taken on days 3-7) or day 12 (if 5-9). Pregnancy rates with Clomid range from 6-10% in most cases. Of the pregnancies that occur using Clomid, 85% will occur in 3 months. 99% will occur within 5 months. Treatment beyond 6 months is generally not seen as useful. There are various other medications that can be used with Clomiphene citrate. Among these are glucocorticoids like dexamethasone, and metformin.
Gonadotropins are hormone medications to make the ovary produce extra follicles. Gonadotropins include follicle stimulating hormone (FSH) and lutenizing hormone (LH). There are several different brand names of medications available. Some drugs which available in our country are Gonal-F, Puregon and Menogon. All are imported and not available in general stores. Drugs are supplied directly to the fertility centers to restore cold chains. As these drugs are heat sensitive so it needs to maintain the temperature. These drugs must be used under the supervision of a doctor to prevent harmful side effects such as ovarian hyperstimulation (OHSS). Detailed mixing and administration instructions are provided in the clinic. Starting dose is usually smaller and adjusted according to the response of the drug. Extensive ultrasonographic monitoring is needed to see the response of the drug and to avoid the OHSS.
It is a gonadotropin releasing hormone (GnRH) agonist which means it should stimulate the release of FSH and LH from the pituitary gland. What is seen, in actuality, is a paradoxical effect. After an initial stimulation of gonadotropin release, GnRHa actually prevents release of FSH and LH. This is the desired clinical application of GnRHa in an ovarian stimulation cycle. By preventing the pituitary gland from stimulating the ovaries with FSH, and preventing LH from triggering ovulation, the ovaries are effectively "turned off". This allows the physician to control the amount of ovarian stimulation by the amount of medication injected. Ovulation is also not likely without the surge of LH that is also blocked by GnRHa. When the follicles are ready, ovulation can be triggered by giving HCG which has structural similarities to LH. After ovulation has been triggered there is no further need to continue GnRHa.
Side effects you may experience while taking GnRHa include hot flashes, vaginal dryness, and headaches. If these side effects occur they will usually resolve after you start taking gonadotropins.
Metformin is an insulin sensitizing medication used to counteract the effect of high circulating insulin levels (hyperinsulinemia). This elevated insulin level has been associated with many diseases including PCOS and insulin resistance. Metformin use has been associated with improved ovulation, weight loss, and decreased pregnancy losses. Common side effects include nausea, bloating, and diarrhea. Metformin is much more effective when combined with a diet aimed at reducing insulin stimulation and a regular exercise program.
For triggering of ovulation
Complications of induction:
This is to prevent hyperstimulation. Ovarian hyperstimulation syndrome (OHSS) can be life threatening. It is not unusual to experience mild symptoms of OHSS. Moderate to severe OHSS may result in cycle cancellation. Things to look for include:
- Rapid weight gain
- Abdominal and pelvic discomfort
- Shortness of breath
The monitoring ultrasounds will help avoid OHSS as well as determining when the growing follicles are most likely to be mature.
For down regulation
These medications directly block the effect of brain's stimulation of the pituitary gland. They can usually be taken for a shorter duration than Lupron. Great care must be taken to avoid accidental ovulation and timing of the medication is crucial. When used properly, these medications can provide equal prevention of ovulation as Lupron. Pregnancy rates are fairly equivalent for between the agonists and antagonists.
For Luteal Support
Human Chorionic Gonadotropin (hCG)
HCG has a chemical structure that is very similar to LH (luteinizing hormone) which triggers ovulation. HCG is also the hormone produced by pregnancies from the chorionic villi and placenta. It is used to minimize the deficient production by the chorionic villi.
Progesterone is produced by the corpus luteum in the ovary after ovulation. During the retrieval process in ART cycles some of the hormone producing cells are removed from the inside of the follicles. As an attempt to support the lining of the uterus and prepare for implantation, supplemental HCG or progesterone is usually used. This supplemental HCG can further stimulate hormone production in the ovary and worsen the symptoms of ovarian hyperstimulation. To avoid this undesired effect progesterone can be administered. There are several forms of progesterone available including vaginal suppositories, and injectable progesterone. Progesterone injections are usually continued until 10-12 weeks of pregnancy.