GP - Contraception: Implantable, Injectable and Intrauterine Contraceptives

Question 1

What are the two intrauterine contraceptives available?

• MOA?
• Effectiveness

Answer 1

• IUD: prevention of fertilisation by causing decreased sperm motility and survival
• IUS (Mirena): levonorgestrel prevents endometrial proliferation and causes cervical mucous thickening
• Both IUD and IUS are more than 99% effective

Question 2

What counselling should you provide for IUS and IUD?

Answer 2

• IUD: effective immediately following insertion

- IUS: can be relied upon after 7/7

Question 3

What problems can occur with IUD/IUS?

Answer 3

IUD
-Makes periods heavier, longer and more painful

IUS
-Associated with initial frequent uterine bleeding/spotting, later women have intermittent light menses with less dysmenorrhea or become amenorrhoiec

Common

• uterine perforation: 2/1000 insertions
• Proportion of ectopic pregnancy is increased but absolute number is reduced compared to women not using contraception
• Infection: small PID risk
• Expulsion: 1/20 and will occur within first 3 months

Question 4

Implantable contraceptive:

-Name and MOA

Answer 4

• Nexplanon: non-biodegradable subdermal contraceptive implant
• MOA: slowly releases progestogen hormone etonogestrel. Inserted in non-dominant arm overlying the tricep. Main MOA is prevent ovulation and also thickening the cervical mucus

Question 5

Nexplanon: key points

Answer 5

• Highly effective: 0.07/100 failure rate
• lasts 3 years
• Doesn’t contain oestrogen so can be used if PMH of thromboembolism/migraine
• Can be inserted immediately following termination of pregnancy

Question 6

Nexplanon: main complaints, drug interactions and CI

Answer 6

• Irregular/heavy bleeding: main problem
• Progestogen effects: headache, nausea, breast pain
• Interactions: enzyme-inducing drugs (anti-epileptics/rifampicin) may reduce efficacy
• C/I: UKMEC 3 (IHD/stroke) and UKMEC 4 (current breast cancer)

Question 7

What is the main injectable contraceptive in the UK?

• Method of delivery
• MOA

Answer 7

• Depo Provera - 150mg medroxyprogesterone acetate
• Method of delivery: IM injection every 12/52
• Can be given up to 14 weeks after last dose without need for extra precaution
• MOA: inhibition of ovulation (primary) and cervical mucus thickening + endometrial thinning (secondary)

Question 8

Depo provera: disadvantages and adverse effects

Answer 8

Disadvantages

• injection cannot be reversed once given
• potential delayed return to fertility (can be up to 12/12)

Adverse effects

• Irregular bleeding
• Wt gain
• May potentially increase risk of osteoporosis (only be used in adolescents if not other method is suitable)
• Not quickly reversible

Question 9

What options, other than pills and methods in this deck, are also available?

Answer 9

• Combined vaginal ring (there are a lot of rules about whether it gets expulsed, delayed insertion/removal or broken - no need to memorise)
• Combined contraceptive patch: Evra patch - needs to be work every day and changed each week - not worn in 4th week where there is a withdrawal bleed.