Reproductive and Urinary System Medications Study Guide

Chapter 20: Reproductive and Urinary System Medications

Overview of the Reproductive and Urinary Systems

• Reproductive System Function: Responsible for the procreation of the species.

  • Disorder Implications: Can cause pain, infertility, and potential death if left untreated.

  • Medication Basis: Most medications for this system are hormone-based.

  • Example: Birth control pills, which prevent pregnancy and help manage painful menstruation.

• Urinary System Function: Primarily responsible for removing toxins from the body while conserving electrolytes.

  • Disorder Implications: Can cause discomfort and pain; untreated urinary system failure can lead to death.

  • Primary Medications:

    • Diuretics: Increase the excretion of water and waste products.

    • BPH Medications: Used for Benign Prostatic Hypertrophy (BPH) to decrease prostate size and allow free urine flow.

Key Terminology

• Androgen: Male sex hormone.

• Benign Prostatic Hypertrophy (BPH): A nonmalignant growth of the prostate gland.

• Enuresis: Bedwetting.

• Estrogen: Primary female sex hormone.

• Follicle-stimulating hormone (FSH): Pituitary hormone regulating sperm and egg production.

• Hormone replacement therapy (HRT): Administration of hormones to replace those no longer produced naturally.

• Interstitial cell-stimulating hormone (ICSH): Male version of LH that regulates testosterone production.

• Luteinizing hormone (LH): Pituitary hormone triggering egg release in women.

• Progestin: Synthetic form of progesterone.

• Sexually transmitted disease (STD): Infection transmitted through sexual contact.

• Tocolytic: Medication used to slow or stop uterine contractions.

Hormones of the Reproductive System

• Gonadotropic Hormones: Secreted by the pituitary gland, these include:

  • Follicle-stimulating hormone (FSH): Regulates sperm production in men and egg production in women.

  • Luteinizing hormone (LH): Triggers egg release (ovulation) and promotes secretion of estrogen and progesterone.

  • Interstitial cell-stimulating hormone (ICSH): Known as LH in men; regulates testosterone production.

• Primary Reproductive Hormones:

  • Androgen (Testosterone): Produced in the testes (testicles); promotes reproductive health, growth, and function.

  • Estrogen and Progesterone (Progestin): Secreted by the ovaries in females.

Summary Table of Reproductive Hormones

Note: Parlodel is used to suppress lactation in women who do not breastfeed, though it may increase fertility as a side effect.

Medications for Female Hormone Disorders

Contraceptive Medications

• Mechanism of Action: Overrides the body's natural production of estrogens and progestins.

  • Inhibits ovulation (egg release).

  • Inhibits fertilization (sperm-egg union).

  • Prevents implantation (embryo embedding in uterine wall).

  • Prevents growth of the fetus.

• Types of Oral Contraceptives ("The Pill"):

  • Monophasic: Constant hormone dose for the first $21$ days. Examples: Ethinyl estradiol and norgestrel (Cryselle $28$, Lo/Ovral $28$, Ogestrel-$28$) or ethinyl estradiol and norethindrone (Aranelle, Modicon, Ortho-Novum).

  • Biphasic: Constant estrogen but two different progestin doses. Examples: Ethinyl estradiol and norethindrone (Jenest-$28$) and ethinyl estradiol and desogestrel (Apri, Desogen, Mircette, Ortho-Cept).

  • Triphasic: Varying estrogen and progestin with three different strengths. Examples: Ethinyl estradiol and norethindrone (Aranelle, Junel FE $1/20$, Ortho-Novum $7/7/7$) and ethinyl estradiol and levonorgestrel (Alesse, Levlite, Lutera, Portia, Tri-Levlen).

  • Minipill: Contains only progestin; slightly less effective. Examples: Errin, Ovrette, Provera.

• Alternative Delivery Methods:

  • Vaginal Ring: Ethinyl estradiol and etonogestrel (NuvaRing). Inserted for $3$ weeks, removed for $1$ week.

  • Implants: Etonogestrel (Implanon, Nexplanon). Small plastic rod in upper arm; lasts up to $3$ years.

  • IUDs:

    1. Hormonal (Mirena): Contains progestin; lasts $5$ years.

    2. Copper: Naturally toxic to sperm; lasts $10$ years.

  • Transdermal Patches: Ethinyl estradiol and norelgestromin (Ortho Evra). Applied weekly for $3$ weeks, then $1$ week off.

• Postcoital (Emergency) Contraception: High-dose estrogen/progestin. Examples: Levonorgestrel (Plan B), ethinyl estradiol and levonorgestrel (Preven EC).

• Abortifacients: Mifepristone (Mifeprex or RU-$486$). Blocks progesterone; used during the first $7$ weeks since last period. Contraindicated with blood thinners like Coumadin.

• Side Effects and Risks:

  • Pregnancy symptoms (weight gain, mood swings, breast tenderness).

  • Serious risk: Blood clots (especially for women >$35$ years old and smokers).

Hormone Replacement Therapy (HRT)

• Indications: Permanent cessation of menses (menopause).

• Estrogen Alone: Used if the woman has no uterus. Oral: Estrace, Premarin; Cream: Estrace, Dienestrol; Patch: Estraderm, Alora, Vivelle.

• Estrogen-Progesterone Combination: Essential if the woman still has a uterus to prevent endometrial cancer. Oral: Prempro; Patch: Climara-Pro.

• Symptoms Relieved: Hot flashes, vaginal dryness, bone loss.

• Risks: Increased risk of breast cancer, stroke, and blood clots.

• Androgen Replacement (Men): Used for declining testosterone; may decrease heart disease and diabetes. Example: Testosterone gel (AndroGel).

Abnormal Uterine Bleeding Treatments

• Goal: Correct hormonal imbalance or regulate menstruation rhythm.

• Gonadotropin-releasing hormone agonists: Leuprolide (Eligard, Lupron) and Goserelin (Zoladex).

  • Function: Suppresses endometrial lining by reducing estrogen (artificial menopause).

  • Duration: Short term (max $6$ months).

  • Side Effects: Hot flashes, bone loss, headaches, increased cholesterol.

Labor and Infertility Medications

Labor Medications

• Cervical Ripening Agents: Topically applied to soften/dilate the cervix. Example: Dinoprostone (Cervidil, Prepidil).

• Oxytocin (Pitocin, Syntocinon): Pituitary hormone causing uterine contractions. Administered IV in monitored settings. Also used to control postpartum bleeding.

• Tocolytics: Slow or stop contractions to prevent premature birth.

  • Magnesium Sulfate: IV for $24$ to $48$ hours; acts as a calcium channel blocker. May reduce cerebral palsy risk.

  • Nifedipine (Adalat CC, Procardia): Oral calcium channel blocker used if cervix is minimally dilated and sac is intact.

  • Indomethacin (Indocin, Tivorbex): Strong NSAID; anti-prostaglandin effect stops contractions. Not used in the last $2$ months of pregnancy due to fetal cardiac risks.

Infertility Medications (Ovulation Stimulants)

• Clomiphene (Clomid, Serophene): Increases FSH and LH. Drug of choice for idiopathic infertility.

• Menotropins (Humegon, Menopur, Pergonal, Repronex): Injections to stimulate follicle ripening.

• Chorionic gonadotropin (Ovidrel, Pregnyl): Injection to trigger mature egg release.

Male Reproductive and Libido Disorders

Erectile Dysfunction (ED)

• Phosphodiesterase type $5$ inhibitors: Work by dilating penile arteries and constricting veins.

  • Examples: Sildenafil (Revatio, Viagra), Vardenafil (Levitra, Staxyn), Tadalafil (Adcirca, Cialis).

  • Usage: Taken orally $30$ minutes to $1$ hour before activity.

  • Contraindications: History of cardiovascular disease, stroke, sickle cell anemia, or eye problems.

• Alprostadil (Caverject, Edex): Urethral pellet or injection into the penis. Works in $5$ to $20$ minutes.

Libido Disorders

• Decreased Libido Causes: Aging, weight changes, depression, and medications.

  • Meds that decrease libido: Benadryl, Aldactone, Aldomet, Catapres, Chlor-Trimeton, Valium, alcohol, Zantac, Tagamet, Dopar, Inderal.

  • Meds that increase libido: Amphetamines.

The Urinary System and Diuretics

• Anatomy: Kidneys (filters), ureters (transfer), bladder (storage), and urethra (removal).

• Diuretics ("Water Pills"): Increase fluid excretion for hypertension, heart failure, and edema.

Classification of Diuretics

• Loop Diuretics: Most effective; work in the loop of Henle. Used for congestive heart failure and renal insufficiency.

  • Examples: Furosemide (Lasix), Ethacrynic acid (Edecrin), Torsemide (Demadex), Bumetanide (Bumex).

• Thiazide Diuretics: Block sodium reabsorption. Used for moderate hypertension.

  • Examples: Chlorothiazide (Diuril), Chlorthalidone (Hygroton), Indapamide (Lozol), HCTZ (Aquazide, Microzide), Metolazone (Mykrox).

• Potassium-Sparing Diuretics: Allow potassium reabsorption while excreting sodium and water.

  • Examples: Amiloride hydrochloride, Spironolactone (Aldactone), Triamterene (Dyrenium).

• Osmotic Diuretics: Increase tissue-to-circulation fluid pull. Used for high intracranial/intraocular pressure or anuric renal failure toxic overdose.

  • Example: Mannitol (Osmitrol). Administered IV only.

Electrolyte Concerns

• Vital Electrolytes: Sodium ($Na$), Potassium ($K$), Calcium ($Ca$), and Magnesium ($Mg$).

• Hypokalemia Risk: Loop and thiazide diuretics cause potassium loss, which can disrupt heart rhythm.

Other Urinary and Specialized Disorders

• Benign Prostatic Hypertrophy (BPH): Treated with alpha-adrenergic blockers to relax smooth muscle.

  • Examples: Alfuzosin (Uroxatral), Doxazosin (Cardura), Dutasteride (Avodart), Finasteride (Proscar), Tamsulosin (Flomax), Terazosin (Hytrin).

  • Dutasteride Detail: Prevents conversion of testosterone to DHT. Must be taken for $6$ months to see effects. Pregnant women must not handle capsules.

• Urinary Tract Infections (UTIs): Treated with broad-spectrum antibiotics (Bactrim, Augmentin), analgesics (Pyridium), and antispasmodics (methenamine, flavoxate).

• Incontinence: Treated with antispasmodics: Darifenacin (Enablex), Fesoterodine (Toviaz), Oxybutynin (Ditropan), Solifenacin (VESIcare), Tolterodine (Detrol), Trospium (Sanctura).

• Enuresis (Bedwetting): Treated with Desmopressin (DDAVP) or Imipramine (Tofranil). DDAVP mimics pituitary vasopressin.

• Urine Color Changes: Preparation is necessary to prevent patient panic.

  • Dark brown/yellow, blue-green, orange-yellow, red-pink.

  • Agents: Some anticoagulants, antibiotics (e.g., Rocephin can cause orange urine), antidepressants, laxatives, barbiturates, and iron salts.

Questions & Discussion

• Q: Why may erectile dysfunction drugs affect the entire cardiovascular system and not just the penis?

  • A: Because these drugs (phosphodiesterase type $5$ inhibitors) act on the vascular system to dilate arteries, their effect is systemic, potentially causing significant drops in blood pressure or heart strain in patients with underlying cardiac conditions.

• Q: Why was Mr. Stephens denied as a blood donor while taking Avodart?

  • A: Because Dutasteride (Avodart) can cause birth defects, men must wait $6$ months after ending treatment before donating blood to prevent exposing women (who may be pregnant) to the drug via transfusion.