Chapter 51: Birth Control Flashcards
BC
Interfering with the reproductive process at any step from gametogenesis to nidation (implantation of a fertilized ovum)
BC methods: pharm
Pharmacologic methods of contraception
Oral contraceptives
Etonogestrel implants
Injectable medroxyprogesterone acetate
Intrauterine devices
Vaginal rings
Transdermal patches
Nonpharm BC methods
Surgical sterilization (tubal ligation, vasectomy)
Mechanical devices (condom, diaphragm, cervical cap)
Avoiding intercourse during periods of fertility (calendar method, temperature method, cervical mucus method)
Considerations for selecting BC
Effectiveness
Safety
Personal preference
Oral BC MOA
Inhibition of ovulation
Classifications of oral BC
Combination oral contraceptives (OCs) -Estrogen and progestin
Progestin-only OCs (“mini-pills”)
3 major subgroups of combo BC
Monophasic
Biphasic
Triphasic
Combo BC ADR
Thromboembolic disorders
Hypertension
Cancer
Stroke in patients with migraine
Teratogenic effects
Abnormal uterine bleeding
Use in pregnancy and lactation
Benign hepatic adenoma
Glucose intolerance
Other adverse effects
*pt education and close follow up
Noncontraceptive benefits of OCs
Decrease risks of ovarian cancer, endometrial cancer, ovarian cysts, pelvic inflammatory disease, benign breast disease, iron deficiency anemia, and acne
Favorable effect on menstrual cycles
Diminished cramps; lighter, shorter, more predictable flow
Combo OC drug interactions
Rifampin
Ritonavir
Antiepileptic drugs
St. John’s wort
*pt education
Drugs whose effects are decreased by OCs
Warfarin
Insulin
Oral hypoglycemics
Drugs whose effects are increased by OCs
Several agents, including theophylline, tricyclic antidepressants, diazepam, and chlordiazepoxide
Dosing schedule of BC
28-day-cycle schedules
Extended cycle and continuous schedules
Mono estrogen and progesterone levels remain constant
Biphasic, triphasic, quad simulate th ovarian production of estrogens and progesterones
Missed dose of BC : 28 day cycle schedule
One or more pills missed first week: Take one pill as soon as possible (ASAP) and continue with the pack; use an additional form of contraception for 7 days
One or two pills missed second or third week: Take one pill ASAP and continue with active pills in the pack; skip placebo pills and go straight to a new pack once all the active pills have been taken
Three or more pills missed second or third week: Follow instructions given for missing one or two pills; also, use an additional form of contraception for 7 days
Missed dose of BC: Extended cycle and continuous schedules
Up to 7 days can be missed with little or no increased risk of pregnancy, provided the pills had been taken continuously for the prior 3 weeks
Progestin-Only Oral Contraceptives
Camila, Errin, Heather, Jolivette, Ortho Micronor, Nor-QD, and Nora-BE
Do not cause thromboembolic disorders, headaches, nausea, or most of the other adverse effects associated with combination OCs
Slightly safer than combination OCs
Progestin-only preparations are less effective
More likely to cause irregular bleeding
Combination Contraceptives with Novel Delivery Systems: Transdermal contraceptive patch [Ortho Evra]
Transdermal contraceptive patch [Ortho Evra]
Application: Once a week for 3 weeks, followed by 1 week off (to permit normal menstruation)
Adverse effects: Breast discomfort, headache, local irritation, nausea, menstrual cramps
Combination Contraceptives with Novel Delivery Systems: nuvaring
Vaginal contraceptive ring [NuvaRing]
One ring is inserted once each month, left in place for 3 weeks, and then removed; a new ring is inserted 1 week later. During the ring-free week, withdrawal bleeding occurs
Most common adverse effects: Vaginitis, headaches, upper respiratory infection, leukorrhea, sinusitis, weight gain, and nausea
Long acting contraceptives: nexplanon
Subdermal etonogestrel implants [Nexplanon]
Among the most effective contraceptives available
Adverse effect: Irregular bleeding
Effective for 3 years
4 cm rod that contains 68mg of edoestrogenol which is a synthetic progestin
Inserted between bicep and tricep in nondominant arm
Long-acting contraceptives: depot
Depot medroxyprogesterone acetate (MPA)
Injected intramuscularly (IM) or subcutaneously (subQ), protects against pregnancy for 3 months or longer
Adverse effects: Menstrual irregularities, bone loss, weight gain
Long0acting contraceptives: IUD
Intrauterine devices (IUDs):
Among the most reliable forms of reversible birth control
Examples: Copper T 380A [ParaGard], Levonorgestrel-releasing intrauterine system [Mirena]
Placed within 7 days of onset of menses
Replacement can be inserted during any phase of the menstrual cycle
ParaGard can remain in place for 10 years
Mirena can remain in place for 5 years
Women need to check their strings
Long-acting contraceptives: spermicides
Chemical surfactants that kill sperm by destroying their cell membrane
Gel, jelly, suppository, vaginal film, and contraceptive sponge
All formulations can be purchased without a prescription
When used alone, only moderately effective
Use with a diaphragm or condom increases efficacy
Drugs for medical abortion
Mifepristone (RU 486) with misoprostol
Blocks uterine progesterone receptors
Adverse effects:
Bleeding
Cramping
Nausea
Vomiting
Diarrhea
Headache
Prostaglandins
Misoprostol, carboprost, dinoprostone
In obstetrics, prostaglandins are indicated for:
Induction of abortion
Cervical ripening before induction of labor
Control of postpartum hemorrhage
