8132MED - Contraception-2.pdf
Document Details
Tags
Full Transcript
Contraception Dr Samantha Waugh Understand the mechanism of action and use of hormonal and Understand non-hormonal contraception options available in Australia, including emergency contraception. Learning Understand...
Contraception Dr Samantha Waugh Understand the mechanism of action and use of hormonal and Understand non-hormonal contraception options available in Australia, including emergency contraception. Learning Understand Understand important contraindications, precautions and drug interactions for different contraceptive methods, particularly Objectives the combined oral contraceptive pill. Describe the Australian categorisation system and database for Describe prescribing medicines in pregnancy and outline the principles of safe prescribing for the pregnant patient. Contraceptives can be classified by their mechanism of action (i.e. hormonal vs non-hormonal) or duration of action (i.e. long vs shorter acting). This lecture will cover the following classes: Long-acting reversible contraception (LARCs) Intrauterine contraceptive devices (IUDs) Etonogestrel contraceptive implant Shorter-acting hormonal contraception Depot medroxyprogesterone injection Classification Combined hormonal contraception – combined oral contraceptives and the vaginal ring Progestogen-only pills Barrier methods of contraception – male (external) and female (internal) condoms, diaphragm Sterilisation – vasectomy and tubal ligation Other contraceptive methods – fertility awareness methods, lactational amenorrhoea method, withdrawal method Emergency contraception – oral emergency contraception, copper IUD Contraceptive choice is influenced by multiple factors and may be relevant to all individuals, regardless of gender identity. Conception may be possible for anyone presumed female at birth (includes cis women, trans men, and some nonbinary individuals). Contraception may also be relevant to anyone presumed male at birth (includes cis men, trans women, and some nonbinary individuals). Factors influencing contraceptive choice include: Contraindications and precautions Drug interactions Effectiveness of the contraceptive method and consequences of an unplanned pregnancy So, how to Need for immediate start choose? Reproductive stage of life Reversibility Non-contraceptive benefits (improvement of acne, dysmenorrhea, heavy menstrual bleeding) Barrier protection important especially if high risk of STIs Risk of sexually transmitted infections Cost and accessibility Long-acting reversible contraception is the most cost effective and reliable method of contraception. real life Efficacy of Contraceptive Significantly Methods low risk of failure most effective are the long-acting options The UK Medical Eligibility Criteria (UKMEC) is a globally recognised system used to classify the contraindications and precautions for contraceptives. It provides advice as to which contraceptive can be used for individuals with specific medical conditions. e.g. method best for with HTN For a given medical condition or patient situation considered by the UKMEC, a category of risk from 1-4 is given. These risk categories are defined as: Contraindications and Precautions For example, inserting an IUD into a patient with untreated gonorrhoea poses an unacceptable risk and would receive a category 4. then not use C = continuing the contraceptive I = initiating the UKMEC contraceptive Example lowest risk is progesterone only pill thickens cervical mucus oestrogen increases coagulation factors mechanisms for combined contraception risk of VTE, cardiovascular clotting both in formulation stop ovulating, progesterone - thickens continuous low level cervical mucus and thins endometrium issue - reduced milk progesterone thin, atrophy of myometrium thicken mucus prostaglandins and cramping not as impactful on ovulation a lot have amenorrhoea and stops bleeding e.g. Myrena thick cervical mucus and thin endometrium variable on ovulation condoms, diaphragm aware of menstural cycle know when ovulated, avoid intercourse in period progesterone no hormones toxic to sperm and fertilised ova release progesterone, copper IUD (toxic presence, non-hormonal) Two types: levonorgestrel-releasing devices and copper IUDs Levonorgestrel-releasing IUDs work by: Long-acting Thickening cervical mucus to prevent sperm penetration reversible Inhibiting sperm migration Interfering with ovum survival consider contraindications for combined pill contraception Inducing endometrial atrophy (LARCs) - Preventing ovulation in some users prevents suvival, variable effect on ovulation cervical mucus effect IUDs Copper IUDs work by: Inhibiting sperm migration toxic, prevent implantation Interfering with ovum survival Preventing implantation In Australia, there are two types of levonorgestrel-releasing IUDs: the mirena (52mg levonorgestrel) and the Kyleena (19.5mg levonorgestrel). Both devices need replacing every 5 years; the mirena is additionally effective for heavy menstrual bleeding, preventing endometrial hyperplasia, and endometriosis. prevent shedding LARCs - IUDs no hormone heavy bleeding Contraindications and Precautions Insertion of ALL types of IUD is contraindicated in the following conditions: Current PID infection fallopian tubes, uterus, cervix Symptomatic chlamydia, and symptomatic or asymptomatic gonorrhoea or Mycoplasma genitalium need to treat first Unexplained vaginal bleeding Gestational trophoblastic disease molar pregnancy, mass in uterus Cervical cancer awaiting treatment Endometrial cancer LARCs - IUDs Insertion of ALL types of IUD requires precaution in the following conditions: asymptomatic - you can but treat Asymptomatic chlamydia (treat on the day of insertion) common genetic abnormality - issue Distortion of the uterine cavity Long QT syndrome (insert within a hospital setting) pull IUD - vagal response 48 hours to 4 weeks postpartum (risk of uterine perforation) high risk Individuals with AIDs Any cardiac condition in which a vasovagal response would be of concern mindful of conditions with hormonal changes In addition, levonogestrel IUDs are contraindicated in individuals with breast cancer and require precaution in individuals with a past history of breast cancer, severe decompensated cirrhosis, hepatocellular adenoma, or those who develop heart disease or stroke during use Advantages Disadvantages Extremely effective (copper: 99.5%:; LNG: Harmful to an ongoing pregnancy pregnancy test 99.7 to 99.9%) Minimal user involvement Requires pelvic exam and procedural works in mestrural period insertion Long-acting Altered bleeding patterns High continuation rate Complications: vaginal bleeding, uterine preferred perforation, expulsion, PID within the first 20 post-partum inserted improperly days LARCs - IUDs 52mg LNG IUD improves endometriosis, dysmenorrhoea, and heavy menstrual Additional adverse effects with LNG-IUDs: Benign ovarian cysts; Mood changes and thins endometrium bleeding headaches; Weight gain; Breast tenderness; heavy and longer periods Acne Safe during breastfeeding Copper IUDs tend to cause heavier and longer periods than pre-insertion Few contraindications and precautions No drug interactions Rapid return of fertility after removal Cost-effective Before starting an IUD pregnancy must be excluded. Assess the risk of an STI and determine whether screening for chalmydia or gonorrhoea is required before insertion. LNG-IUDs are immediately effective if: Inserted on day 1-5 of a regular menstrual cycle shedding, bleeding phase Inserted