PHARM 562 Pharmacotherapeutics V Spring 2014 UW School of Pharmacy
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PHARM 562 Pharmacotherapeutics V Spring 2014 UW School of Pharmacy PHARM 562 PHARMACOTHERAPEUTICS V CONTRACEPTION Lingtak-Neander Chan, PharmD, BCNSP School of Pharmacy University of Washington TEL : (206) 543-7987 Email : [email protected] OBJECTIVES: Contrast the pharmacological differences among synthetic progestins and estrogens. Understand the mechanism of action of emergency hormonal contraception. Determine the relative risks vs benefits of different hormonal contraceptive approaches in a woman according to her history and other factors. Determine an alternative contraceptive method in a woman who experiences side effects from her existing contraceptive regimen. Identify the clinically important interacting drugs that may alter the efficacy or safety of hormonal contraceptive agents and determine the management approaches to minimize the incidence of undesirable events. Evaluate the alternative contraceptive options in the following special patient populations: a. Postpartum women b. Transplant recipients c. Bariatric surgery recipients d. Patients with HIV infection/AIDS e. Patients with epilepsy Metabolic pathway of steroid hormones: L. Chan, PharmD Page 1 PHARM 562 Pharmacotherapeutics V Spring 2014 UW School of Pharmacy Regulation of the Menstrual Cycle. PROGESTINAL EFFECT ANDROGENIC EFFECT ESTROGENIC EFFECT L. Chan, PharmD Page 2 PHARM 562 Pharmacotherapeutics V Spring 2014 UW School of Pharmacy I. PHARMACOLOGIC CHARACTERISTICS OF PROGESTINS. PROGESTINS NATURAL SYNTHETIC Progestins Progestins Progesterone SPIRONOLACTONE derivatives PROGESTERONE TESTOSTERONE Drospirenone derivatives derivatives Pregnane 19-Norpregnane derivatives derivatives Medroxyprogesterone Nomegestrol Estrane Gonane acetate acetate derivatives derivatives Megestrol acetate Nestorone Norethindrone Norgestrel Norethindrone acetate Levonorgestrel Ethynodiol diacetate Desogestrel Norethynodrel Gestodene Norgestimate Etonogestrel Dienogest L. Chan, PharmD Page 3 PHARM 562 Pharmacotherapeutics V Spring 2014 UW School of Pharmacy General comparison among different synthetic progestins currently used in contraceptive agents: - estrogenic estrogenic androgenic mineralo - - - Progestin Estrogenic Effect Anti Effect Androgenic Effect Anti Effect Glucocorticoid Anti corticoid Progesterone - + - +/- + + Medroxyprogesterone - + +/- - + - acetate Nomegestrol - + - +/- - - Estranes* + + + - - - Levonorgestrel - + + - - - Norgestimate - + +(/-) - - - Drospirenone - + - + - + * Norethisterones derivatives, including norethindrone, norethidrone acetate, ethynodial diacetate, norethinodrel Relative progestogenic potency: Ovulation Inhibition Transformation (mg/day PO) (mg/cycle) Progestin Progesterone 300 4200 Medroxyprogesterone acetate 10 60 Norethindrone 0.5 – 1.0 10 – 15 Norethindrone acetate 0.5 ~ 30 Levonorgestrel 0.05 6.0 Desogestrel 0.06 2.0 Norgestimate 0.2 7.0 Dienogest 1.0 6.0 Drospirenone 2.0 50 Pharmacokinetic Comparison Oral Tmax Peak/Trough bioavailability concentrations Progestin Micronized progesterone 300 mg 2 – 2.7 hrs 30/<2 ng/mL Medroxyprogesterone acetate -- -- -- Norethindrone 1 mg -- 1 – 2 hrs 16/<0.5 ng/mL Levonorgestrel 0.15 mg 72 – 100 % 1 – 3 hrs 3.5/<1 ng/mL L. Chan, PharmD Page 4 PHARM 562 Pharmacotherapeutics V Spring 2014 UW School of Pharmacy II. PHARMACOKINETIC PROFILE OF SYNTHETIC ESTROGEN AND PROGESTINS. Estradiol valerate Mestranol Ethinyl estadiol: CYP3A4, 2C9 UGT1A genes Oral bioavailability = 25 – 65 % Tmax 1 to 6 hours Sulfates undergo enterohepatic recirculation and ~30% deconjugated back to EE T1/2 = 6 – 27 hrs Inter-ethnic variation of PK reported L. Chan, PharmD Page 5 PHARM 562 Pharmacotherapeutics V Spring 2014 UW School of Pharmacy Progestinogenic agents: Oral bioavailability: o Norethindrone 47 – 73 % o Levonorgestrel, gestodene, dienogest > 90 % o Other estranes 20 – 40 % o 3-keto-desogestrel 60 – 75 % o Drospirenone 70 – 80 % Tmax 1 to 3 hours -- Substrates of CYP 2C9, 2C19, and 3A4; SULF, and UGTs -- T1/2 : . Norethindrone: 8 – 12 hrs . Drospirenone: ~ 30 hrs . Other testosterone derivatives: 12 – 30 hrs L. Chan, PharmD Page 6 PHARM 562 Pharmacotherapeutics V Spring 2014 UW School of Pharmacy III. PERICOITAL CONTRACEPTION. EMERGENCY CONTRACEPTION. Mechanism of Action: Most desirable treatment window: A. Yuzpe method (non-FDA approved use) Variation of products to deliver comparable amount of EE + LNG http://ec.princeton.edu/questions/dose.html#dose B. Ulipristal acetate 30 mg (ella) C. Levonorgestrel 0.75 mg x2 D. Levonorgestrel 1.5 mg x1 E. Other non-FDA approved, LNG-based regimens F. Copper IUD Glasier AF et al. Lancet 2010 Practical Issues: 1. What are the patient counseling points for EC? 2. How can the side effects of EC be reduced/minimized? 3. What happen if vomiting occurs after taking the dose? L. Chan, PharmD Page 7 PHARM 562 Pharmacotherapeutics V Spring 2014 UW School of Pharmacy IV. CONSIDERATIONS BEFORE INITIATING HORMONAL CONTRACEPTION. Refer to CDC/MMWR report 2013 for screening criteria. Conditions where progestin-only methods are more appropriate (ACOG and WHO recommendation): Migraine headaches, especially those with focal neurologic signs such as an aura Cigarette smoking and > 35 years of age Obesity (ACOG, not WHO) Hypertension, (especially uncontrolled) with vascular disease (or > 35 y.o. – ACOG) Systemic lupus erythematosus with vascular disease, nephritis or antiphosphlipid antibodies Diabetes with associated peripheral vascular disease (WHO) History of thromboembolic diseases or thrombogenic mutations Cerebrovascular disease (current or remote) Coronary artery disease Congestive heart failure Known or suspected breast cancer History of estrogen-dependent neoplasia Undiagnosed abnormal genital bleeding (WHO) Benign or malignant liver tumors, active liver disease, liver failure (WHO) Hypertriglyceridemia (ACOG) Less than 3 weeks postpartum Risk for venous thromboembolic events in users of combined oral contraceptives: Risk of venous thrombosis associated with duration of use of oral contraceptive. Data from MEGA Case-Control Study (BMJ 2009) L. Chan, PharmD Page 8 PHARM 562 Pharmacotherapeutics V Spring 2014 UW School of Pharmacy Duration of Use Odds Ratio (95% CI) No oral contraceptive use 1.0 ≤ 3 months 12.6 (7.1 – 22.4) 3 – 6 months 8.3 (4.7 – 14.5) 6 – 12 months 7.5 (4.7 – 12.2) 12 – 24 months 5.0 (3.4 – 7.4) 24 – 60 months 5.0 (3.7 – 6.8) > 60 months 5.2 (4.3 – 6.2) Using 30 mcg EE as reference, 20 mcg EE is associated with lower risk for VTE (OR 0.8; 95%CI 0.5 to 1.2), whereas 50 mcg EE is associated with higher risk for VTE (OR 1.9; 95%CI 1.1 to 3.4) V. NON-ORAL ROUTE CONTRACEPTIVE APPROACHES A. Intrauterine Device (IUD) a. Intrauterine copper contraceptive (ParaGard) 176 mg copper coiled along vertical stem + 68.7 mg copper on each side of the horizontal stem Replace every 10 year (or sooner if indicated) b. Levonorgestrel-releasing intrauterine system A T-shaped polyethylene frame with a reservoir containing levonorgestrel 52 mg (Mirena) or 13.5 mg (Skyla) Approved for (i) intrauterine contraception for up to 5 years (Mirena) or 3 years (Skyla); (ii) treatment of heavy menstrual bleeding (Mirena) Recommended for women who have at least one child Steady state levonorgestrel serum concentration between 150 – 200 pg/mL B. Medroxyprogesterone acetate injectable suspension a. Depo-Provera intramuscular injection – 150 mg MPA deep IM Q13weeks b. depo-subQ provera 104 – 104 mg/ 0.65 mL SQ Q12 – 14 weeks Immediately effective if administered within 5 days of menstrual cycle Return of fertility upon discontinuation: o IM : up to 22 months o SQ : 7 – 12 months Absolute contraindications: (i) pregnancy; (ii) breast cancer BLACKBOX WARNING: Loss of bone mineral density Non-contraceptive health benefits: o Decrease endometrial carcinoma o Reduce incidence of iron deficiency anemia o Decrease ovarian cysts o Decrease dysmenorrheal L. Chan, PharmD Page 9 PHARM 562 Pharmacotherapeutics V Spring 2014 UW School of Pharmacy Major adverse events: . Irregular bleeding/ spotting (50% first year 30 - 35 % second year) . 80% patients amenorrhea by year 3 . Weight gain (5.4, 8.1, 13.8 lb first 3 yrs respectively) (35 - 40 %) . Acne . Hair problem . Headache (16.5%) . Abdominal discomfort (11.2 %) C. Etonogestrel implant Progestin-only hormonal subdermal implant for up to 3 years 68 mg etonogestrel (3-keto-desogestrel) Release rate : 60 to 70 mcg/day in Week 5 to 6; decreases to approximately 35 to 45mcg/day at the end of the first year, to approximately 30 to 40mcg/day at the end of the second year, and then to approximately 25 to 30mcg/day at the end of the third year. Most common side effects: o Irregular menstrual flow/ bleeding . Infrequent bleeding (< 3 episodes/90 days): 33% . Amenorrhea (0 episode/90 days): 22% . Prolonged bleeding (Any 1 episode >14 days/90 days: 18% . Frequent bleeding (> 5 episodes/90 days): 7% o Headache: 25% o Vaginitis: 14.5 % o Weight gain: 13.7 % o Acne: 13.5 % Drug interaction potential: Etonogestrel is a CYP3A4 substrate. D. Etonogestrel (ETO)/ Ethinyl estradiol (EE) vaginal ring (NuvaRing) Contains 11.7 mg etonogestrel and 2.7mg ethinyl estradiol Release rate 120 mcg ETO and 15 mcg EE/ day Insert for 3 weeks followed by a week of ring-free period o Starting in a contraceptive-naïve woman – insert on day 1 o Switching from OC to the ring – switch any day o Switching from progestin-only product – the day for the next dose/ injection/ etc Major complications: Drug interactions L. Chan, PharmD