Combined Oral Contraceptive Pill (COC)

Last updated 20.09.12

 

Definition

- Oral contraceptive pill containing both oestrogen & progesterone

 

Features

- Hormal oral contraceptive

- Prevents ovulation

- 99.5% effective if taken correctly

-  0.2-3% failure rate in practice

- If taken >12hrs late should cover w alternative contraception for next 7 pills

- Tricycling

-  Omitting the sugar pills for 3 cycles

-  Break through bleed every 3 months

-  For convenience or dysmenorrhoea

- Some patients omit sugar pills altogether & therefore no bleeding

-  No evidence of harm

- Benefits

-  Reduced menstrual flow & dysmenorrhoea

-  Lower incidence of endomentrail Ca (50% after 3yrs) & ovarian Ca (80% after 10yrs)

-  Less S/S of ovarian cysts, acne & premenstrual S/S

-  Reduced bacterial STIs after 12months use

 

Complications

- Liver adenoma w increased dosing (rare)

- No increase in breast Ca

- Trend for development of invasive cervical Ca w increased use

 

Contraindications

- Hx or at high risk of DVT, PE, AMI, Stroke

- Thrombophillia

- Pregnancy

- Oestrogen dependant Ca, breast Ca, BRCA mutation

- Migraine with aura (risk of stroke)

- Age >35yrs & smoking

- Acute liver disease: active hepatitis..

- Relative Contraindications

-  HTN, hyperlipidaemia, DM

-  Cholelithiasis

-  Sickle cell anaemia

-  Impending surgery with expected several day bed rest (cease 4 days+ prior)

-  Obesity

-  BMI 30-34: benefit vs risk (MEC 2)

-  BMI >35: avoid use (MEC 3)

- Drug Interactions

-  Anticonvulsants (except Sodium valproate, Clonazepam, Vigabatrin, Gabepentin)

-  Induce hepatic enzymes, contraception less effective

-  For effective contraception need 50mcg+ of oestrodiol

-  Not recommended if on Lamotrogine (seizure control may be difficult)

-  Broad spectrum antibiotics

-  Antacids & laxatives (absorption)

-  High dose Vitamin C if ceased abruptly

 

Types

- Microgynon (monophasic)

-  150mcg levonogestrel &..

-  20 ED = 20mcg etinylestradiol

-  Low dose pill for side effects

-  30 ED = 30mcg etinylestradiol

-  50 ED = 50mcg etinylestradiol

-  High dose pill for breakthrough bleeding or on hepatotoxic medications (Anticonvulsants..)

- Diane 35 ED

-  Cyproterone or Norethisterone as progesterone

-  Anti-androgenic activity: Mx acne, hirsuitism, pimples

-  Not specifically indicated for contraception

- Yasmin

-  Drosperidone as progesterone

-  Anti-androgenic action: pimples

 

Mx

- Commencement

-  Dont need to wait for start of menstruation

-  Exclude pregnancy if possible

-  Effective after 7 days of hormone tablets

- Missed pills

-  Take pill straight away

-  Take next pill when due (may mean x2 pills in one day)

-  If >48hrs since last pill (missed dose >24hrs)

-  Use condoms for 7days

-  If <7 pills taken since last placebo consider emergency contraception if unprotected sex in last 5days

-  If <7 pills left before next placebo skip placebo pills, continue active pills

-  If <48hrs since last pill (missed dose <24hrs)

-  Nil further action required

-  Pill will continue to be effective

 

 

 

References

 

Southern Health: Contraception Guidelines, March 2007

Family Planning Victoria, Kathy McNamee, August 2012

UK MEC Criteria for Contraception