Gonadotropic Hormones: FSH, LH, and ICSH

Gonadotropic Hormones

• Optimal functioning of the testes and ovaries relies on gonadotropic hormones and their interactions.

Key Hormones

• Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH), and Interstitial Cell Stimulating Hormone (ICSH) regulate female estrogen and progestin, and male testosterone.
• FSH regulates sperm and egg production.
• LH triggers egg release and promotes estrogen and progesterone secretion in women.
• In men, LH (ICSH) regulates testosterone production.
• Fertility can be affected if hormone levels are too high or low.
• Too little progesterone may prevent a pregnancy from being sustained.
• Too much FSH or LH may result in multiple births.

Contraceptives

• Medroxyprogesterone prevents pregnancy and stabilizes menstrual cycles.
• Hormone replacement medications like testosterone (AndroGel) are used when naturally occurring hormones are lacking.
• Contraceptive drugs are commonly based on hormones women naturally produce.
• Hormones prevent pregnancy by overriding the body's mechanism for producing estrogen and progesterone.
• A common form of birth control is the pill.
• Birth control pills provide varying amounts of estrogen and progestin during the menstrual cycle.
  • Monophasic pills (ethinyl estradiol) deliver a constant amount of hormone during the first 21 days of the cycle.
  • Triphasic pills (ethinyl estradiol) contain varying amounts of estrogen and progestin with different strengths during the monthly cycle, each dose annotated with a specific color.
  • Minipills (progestin; Errin, Ovrette, Provera) are slightly less effective and contain only progestin.
• Patients taking contraceptive pills may experience pregnancy symptoms.
• Postcoital high-dose estrogen (Plan B) can prevent pregnancy if contraception fails.

Methods of Contraceptive Hormone Delivery

• Contraceptive hormones can be delivered through vaginal rings, implants, intrauterine devices (IUDs), and transdermal patches.
  • NuvaRing is a flexible ring containing estrogen and progesterone inserted into the vagina every month, removed every 3 weeks and replaced with a new one a week later.
  • Mirena (levonorgestrel intrauterine system) contains progestin, making the uterus a poor environment for sperm and can remain in place for up to 5 years.
  • Etonogestrel is the only available implant that prevents ovulation and implantation of the egg.
  • Implants are small, plastic rods containing medication placed in the upper arm, providing contraception for up to 3 years.
  • Copper IUDs are naturally toxic to sperm and remain in place for up to 10 years.
  • Transdermal patches contain ethinyl estradiol and norelgestromin to prevent ovulation, applied weekly for 3 weeks.
• A serious side effect of all forms of contraceptives, increased with smoking and in women over 35, is blood clots.
• Only barrier devices (Encare and Conceptrol) are effective against STDs and in preventing pregnancy.

Hormone Replacement Therapy

• Women experiencing menopause may opt for hormone replacement therapy (HRT).
• Taking estrogen without progesterone increases the risk of endometrial cancer.
• Combination estrogen-progestin therapy is prescribed as a pill (Prempro) or patch (Climara Pro).
• HRT decreases bone loss and cardiovascular dysfunction.
• HRT increases the risk of breast cancer, stroke, and blood clots.
• Menopause refers to the permanent cessation of menses.
• Hormone replacement therapy has been used to treat prostate cancer in men by decreasing testosterone levels.

Abnormal Uterine Bleeding

• Abnormal uterine bleeding refers to irregular or excessively heavy vaginal bleeding.
• Correcting hormonal imbalances usually corrects it.
• Progestins (progesterone) alone can regulate the rate, rhythm, and amount of menstruation.
• Leuprolide (Eligard, Lupron) and goserelin (Zoladex) are gonadotropin-releasing hormone antagonists.
• These antagonists suppress the buildup of the endometrial lining in endometriosis patients by reducing estrogen levels.
• Gonadotropin-releasing hormone antagonists are given once a month, lasting no more than 6 months.
• Symptoms of endometriosis mimic those of menopause: hot flashes, bone loss, lack of menstrual periods, mood swings, insomnia, headaches, vaginal dryness, and increased cholesterol levels.

Labor Medications

• Labor needs to occur when the baby is fully developed and able to survive outside the mother's womb.
• Cervical ripening agents and oxytocin speed up labor.
• Tocolytics slow or stop labor.

Cervical Ripening Agents

• Applied topically to the uterus to soften the cervix, initiating dilation.
• Dinoprostone (Prepidil) is a prostaglandin used.
• If administering dinoprostone in gel form to soften the cervix, wait 6 hours before applying a second dose.

Oxytocin

• Speeds up labor by stimulating the uterus to contract.
• Dinoprostone and oxytocin should never be used together due to stronger than desired effects.
• Synthetic oxytocin (Pitocin) can encourage uterine contractions if labor fails to progress, administered via IV.
• Synthetic oxytocin (Pitocin) can be given after birth to contract the uterus and control postpartum bleeding.

Tocolytics

• Slow or stop uterine contractions to prevent premature birth and allow the baby to mature.
• Terbutaline (Brethine) is labeled as a bronchodilator but also acts as a beta-blocker to decrease uterine contractions.
• Terbutaline is usually the first drug given to treat preterm labor, used on a short-term basis of 24 to 48 hours.
• Magnesium sulfate has not been proven to stop preterm labor but is commonly used to treat preeclampsia and premature labor.
• Magnesium sulfate is given via IV for 24 to 48 hours, acting as a calcium channel blocker by keeping calcium from the uterus, which is needed to contract.
• Magnesium sulfate may reduce cerebral palsy risk in preterm infants, but side effects include hypotension, cardiac arrhythmias, and weakness.
• Nifedipine (Adalat CC, Procardia) is a calcium channel blocker that relaxes smooth muscle, including the uterus.
• Nifedipine is used when the cervix is minimally dilated, the amniotic sac is intact, and other tocolytic medications have not been successful.
• Indomethacin (Indocin) is a strong NSAID administered via IV, oral, or rectal route with anti-prostaglandin effects necessary for uterine contractions. Used for joint conditions.
• Indomethacin should be used less than 7 days in the last 2 months of pregnancy.

Ovulation Stimulants

• Help ovaries release multiple eggs, increasing the chance of fertilization.
• Clomiphene is the drug of choice when infertility has no obvious cause and has minimal side effects.
• Menotropins (Humegon, Menopur, Repronex) are given as an injection to stimulate follicle ripening and release, indicated when a woman has functional ovaries but lacks hormonal stimulation.
• Chorionic gonadotropin (Ovidrel, Pregnyl) is given as an injection with clomiphene to stimulate the release of a mature egg.
• Patients undergoing fertility drug treatment should prepare for the possibility of pregnancy with multiple fetuses.

Premenstrual Dysphoric Disorder

• Frequently treated with SSRIs.
• Common symptoms include hot flashes, depression, anxiety, and pain.

Vaginal Infections

• Treated with antibacterials (metronidazole "Flagyl"), antivirals (acyclovir "Zovirax"), and antifungals (miconazole "Monistat").

Androgens

• Male sex hormones that promote the maturation of male sexual organs and characteristics.

Erectile Dysfunction

• Clinical term for male impotence.
• Linked to diabetes, stroke, hypertension, and atherosclerosis.
• Psychological explanations include guilt, fatigue, depression, and fear of failure to perform.
• Drugs, such as phosphodiesterase type 5 inhibitors, dilate the arteries leading to the penis and constrict the veins, sustaining an erection.
• Erectile dysfunction medications like sildenafil (Revatio, Viagra), vardenafil (Levitra, Staxyn), and tadalafil (Adcirca, Cialis) can be dangerous for patients with a history of cardiovascular disease, stroke, sickle cell anemia, or eye problems.
• Alprostadil (Caverject, Edex) can be injected directly into the penis or inserted as a urethral pellet.
• Alprostadil works within 5 to 20 minutes and lasts about 1 hour.
• Alprostadil should be taken no more than once a day and three times a week; side effects include mild pain at the injection site.

Libido

• Reduced libido can occur in both men and women as a result of emotional or physiological changes, depression, or physical changes of aging.
• Medications that can decrease libido include Benadryl, Aldactone, Aldomet, Catpres, Chlor-Trimeton, Valium, Alcohol, Zantec, Tagmet, Dopar, and Inderal.
• Amphetamines increase libido.

Urinary System

• The main function is to filter blood and remove waste products.
• Consists of the kidneys, ureters, bladder, and urethra.
• Kidneys act as filters, ureters transfer filtered waste to the bladder, and the urethra removes waste from the body.

Human Chorionic Gonadotropin

• When administered in an injection, increases testosterone levels and sperm production in males.
• Occurs naturally in women and may be used to treat male infertility.

Diuretics

• Most commonly used medications for urinary system disorders.
• Increase excretion of body fluids from the kidneys, commonly referred to as water pills.
• Used for hypertension and heart failure by decreasing circulating volume to lessen pressure on vessels.
• Also used for kidney failure when hypertension and edema are present.
• Treat kidney stones by lessening calcium excreted in urine.

Types of Diuretics

• Loop, thiazide, potassium-sparing, and osmotic diuretics.
• Most effective diuretics work in the Loop of Henle.
• Loop diuretics are mainly used for congestive heart failure to decrease the volume of blood that the heart circulates through the body.