Reproductive System Pharmacology

Reproductive Hormones

• Gonadotropic hormones support optimal function of testes and ovaries.
• The pituitary gland secretes follicle-stimulating hormone (FSH), which regulates sperm and egg production.
• The pituitary gland also secretes luteinizing hormone (LH), which triggers egg release and promotes estrogen and progesterone secretion.
• Interstitial cell-stimulating hormone (ICSH), the male equivalent of LH, regulates testosterone production.

Contraceptive Pills

• They provide varying amounts of estrogen and progestin during the menstrual cycle.
• Monophasic pills: Contain a constant amount of hormone for the first 21 days of the cycle
  • Examples: ethinyl estradiol and norgestrel (Cryselle 28, Lo/Ovral 28, Ogestrel-28); ethinyl estradiol and norethindrone (Aranelle, Ortho-Novum)
• Biphasic pills: Provide a constant dose of estrogen but two different doses of progestin in the monthly cycle; allows the uterine lining develops normally during the menstrual cycle
  • Examples: ethinyl estradiol and norethindrone (Jenest-28); ethinyl estradiol and desogestrel (Apri, Ortho-Cept)
• Triphasic pills: Contain varying amounts of estrogen and progestin in three different strengths during the cycle
  • Examples: ethinyl estradiol and norethindrone (Aranelle, Ortho-Novum 7/7/7); ethinyl estradiol and levonorgestrel (Alesse, Portia)
• Mini pill: Contains only progestin and is slightly less effective. An example is progestin (Errin, Provera).
• Symptoms of pregnancy may occur with contraceptive pills.

Other Contraceptives

• Postcoital high-dose estrogen, such as levonorgestrel emergency contraceptive (Plan B) or ethinyl estradiol and levonorgestrel (Preven), can prevent pregnancy when contraception has failed.
• Contraceptive Ring : It contains the hormones estrogen and progestin, it is inserted into the vagina every month, removed after 3 weeks to allow for menstruation and it prevents ovulation, fertilization, and implantation
• Contraceptive Implant : It is a small plastic rod placed in the upper arm that contains hormones to prevent ovulation, inhibit sperm from reaching the uterus, and prevents implantation of the egg. It lasts for up to 3 years.
  • Etonogestrel (Implanon)
• Intrauterine Device (IUD) can use Levonorgestrel intrauterine system
• Transdermal contraceptive patches like ethinyl estradiol and norelgestromin (Ortho Evra patch), are applied weekly for 3 weeks, followed by a patch-free week for menstruation.
• Hormonal contraceptives carry risks like blood clot formation, especially in women over 35, and increased clot risk with smoking.
• Barrier devices like condoms and diaphragms, especially those with spermicides containing nonoxynol-9, are effective against sexually transmitted diseases.
• Mifepristone (Mifeprex), formerly RU-486, blocks progesterone and may be used orally for abortion within 7 weeks since the last period; contraindicated with blood thinners.

Hormone Replacement Therapy (HRT) in Women

• Used for women experiencing menopause.
• It replaces hormones no longer naturally produced.
• If the uterus is removed, estrogen is used.
• If the uterus is intact, estrogen is combined with progestin.
• Oral estrogen HRT examples: Estrace, Premarin.
• HRT estrogen cream examples: Estrace, Dienestrol.
• HRT estrogen patch examples: Estraderm, Vivelle.
• Combination estrogen/progestin examples: Prempro (Pill), Climara-Pro (Patch).
• Combination estrogen/testosterone examples: Covaryx (Pill), Estratest (Pill).
• HRT benefits include decreased bone loss and cardiovascular dysfunction, but also increased risk of breast cancer, stroke, and blood clots.

Hormone Replacement Therapy in Men

• Estrogen can decrease testosterone levels in men with prostate cancer.
• Male menopause involves decreased testosterone levels.
• Testosterone replacement has potential to decrease the risk of heart disease, diabetes, and death.
  • AndroGel is rubbed into the skin daily.

Medications for Abnormal Uterine Bleeding

• Estrogen/progesterone is found in oral contraceptives correct hormonal imbalances.
• Gonadotropin-releasing hormone agonists suppress endometrial lining buildup by suppressing estrogen. They are given as monthly injections for no more than 6 months.

Labor Medications

• Cervical ripening agents applied topically, like Dinoprostone (Prepidil), soften the cervix to induce labor.
• Oxytocin (Pitocin, Syntocinon) causes the uterus to contract, administered IV in a controlled setting and may be given postpartum to control bleeding.
• Tocolytics slow or stop uterine contractions to prevent premature birth.
• Terbutaline (Brethine) allows the fetus to mature but is short-term.
• Magnesium sulfate is given IV to treat preeclampsia and slow premature labor
• Nifedipine (Adalat CC, Procardia) is an oral calcium channel blocker that relaxes smooth muscles of the uterus. Preferred short-term use.
• Indomethacin (Indocin) is a strong NSAID that is given IV, PO, or PR and used for less than 7 days. it's effects are minimized on the developing fetus, and is not for use during the last 2 months of pregnancy.

Infertility Medications

• Ovulation stimulants such as Clomiphene (Clomid, Serophene) increase FSH and LH to initiate ovulation when there's no obvious cause for infertility and has minimal side effects.
• Menotropins (Humegon, Menopur, Repronex) are injections that stimulate follicle ripening and release, for use only when the ovaries are functioning, but hormonal stimulation lacking.
• Chorionic gonadotropin (Ovidrel, Pregnyl) is an injection to stimulate the release of a mature egg.

Other Female Reproductive Disorder Medications

• Selective serotonin reuptake inhibitors (SSRIs) relieve symptoms related to premenstrual dysphoric disorder
• Metronidazole (Flagyl) given IV or PO, treats trichomonas
• Acyclovir (Zovirax) given IV or PO, treats herpes

Erectile Dysfunction, Decreased Libido, and Infertility Medications

• Androgens are male sex hormones that promote maturation of the male organs and male sexual characteristics
• Erectile dysfunction is commonly related to Atherosclerosis, Diabetes, Stroke and Hypertension
• Phosphodiesterase type 5 inhibitors dilate arteries leading to the penis and constrict veins.
  • Sildenafil (Revatio, Viagra) is dangerous for those with histories of heart disease, stroke, sickle cell anemia, etc.
• Alprostadil (Caverject, Edex) may be injected into the penis or inserted as a urethral pellet, and it works in 5-20 minutes.
• Human chorionic gonadotropin (hCG) causes a testosterone injection which increases sperm production

Diuretics

• Also called water pills
• Increase excretion of body fluids from kidneys
• Loop Diuretics : Loop of Henle to inhibit sodium and chloride reabsorption
  • Bumetanide (Bumex): PO, IV, IM
  • Ethacrynic acid (Edecrin): PO, IV
  • Furosemide (Lasix): PO, IV, IM
  • Torsemide (Demadex): PO, IV
• Thiazide Diuretics : Block sodium reabsorption and increase water excretion. They treat moderate hypertension, supplements for potassium loss.
  • Hydrochlorothiazide (HydroDIURIL): PO
  • Chlorothiazide (Diuril): PO, IV
• Body needs Sodium (Na), Potassium (K), Calcium (Ca), and Magnesium (Mg) as part of Electrolytes. Electrolytes are replaced through IV or PO supplements. Diuretics require close monitoring of electrolyte levels.
• Potassium Sparing Diuretics : Minimize potassium loss
  • Amiloride (Midamor): PO
  • Spironolactone (Aldactone): PO
• Osmotic Diuretics : ↑ Intracranial pressure, ↑ Intraocular pressure, Anuric stage of acute renal failure, Toxic overdose
  • Mannitol (Osmitrol) is given IV under close supervision

Benign Prostatic Hypertrophy (BPH)

• Alpha-adrenergic blockers relax smooth muscle, which include:
  • Dutasteride (Avodart)
  • Finasteride (Proscar)
  • Tamulosin (Flomax)

Other Urinary Disorder medications

• For Urinary tract infections (UTIs): Broad spectrum antibiotics (Bactrim, Augmentin), Analgesics (Pyridium), Antispasmodics (methenamine, flavoxate)
• Gout, caused by the inability of kidneys to clear uric acid from blood,
• Antispasmodics (Darifenacin (Enablex), Tolterodine (Detrol)) treat urinary incontinence
• (Desmopressin (DDAVP), Imipramine (Tofranil)) treat Enuresis

Effects Medications have on Urine Color

• Antibiotics, anticoagulants, and laxatives can effect the color of a persons urine
  • Dark Brown
  • Yellow
  • Blue Green
  • Orange/Yellow
  • Red/Pink

Questions covering hormones, contraceptives, and medications affecting the reproductive and urinary systems. Topics include sperm production regulation, hormone replacement therapy, and tocolytics.