Hormonal Contraception ผศ. พญ. มาลียา มโนรถ

Hormonal Contraception Oral contraceptives (OCs) Combination of estrogen & progestogen Progestogen only Postcoital contraception Injectable contraceptives Implanted contraceptives

Combination Oral Contraceptives Estrogen + Progestogen (21, 28) Estrogen component –Ethinyl estradiol (EE) –Mestranol (ME) Progestogen component –Norgestrel –Desogestrel –Gestodene

Combination Oral Contraceptives 1. Monophasic pills EE 0.03 mg + Norgestrel 0.15 mg 2. Biphasic pills: EENorethindrone D (mg) D Triphasic pills: EENorgestrel D (mg) D D

Mechanism of action 1. Inhibition of ovulation 2. Effect on the uterine tubes & endometrium ฎ decrease the likelihood of fertilization & implantation 3. A change in the cervical mucus

Contraindications Thromboembolic phenomena Abnormal vaginal bleeding Abnormal liver function Cancer Obesity, smoking, 35 yrs

Adverse Effects Nausea, mastalgia Breakthrough bleeding Vaginal infections Vascular disorders Cholestatic jaundice

Drug Interactions 1. Antibiotic : ampicillin Interrupted enterohepatic circulation Inhibition of intestinal flora 2. Anticonvulsants : phenobarbital Enzyme induction 3. Antituberculous drug : rifampicin Enzyme induction

Contraception with progestins alone 1. PO : small dose of progestins minipills 2. Injection : depot medroxy progesterone acetate 3. Implatation : Implant under the skin

Postcoital Contraceptives Conjugated estrogens :10 mg x 3 for 5 d Ethinyl esradiol : 2.5 mg x 2 for 5 d Diethylstilbestrol : 50 mg x 1 for 5 d Norgestrel 0.5 mg + EE 0.05 mg : 2 tab & 2 in 12 h

Mifepristone (RU 486) An antagonist at progesterone receptor Luteolytic effect (+ prostaglandin) Adverse effects : vomiting, diarrhea, cramps

Chemical Contraception in Man Gossypol –Phenolic compound –Cotton plant : Genus Gossypium -- ฏ sperm density –Side effects : hypokalemia transient paralysis