Progesterone Only Pill (POP, Minipill, Micronur)

Last updated 18.03.13

 

Index

 

Definition

- Oral contraceptive pill containing only progestegen (no oestrogen)

 

Features

- Progestogen (synthetic progesterone)

- 0.5-4% failure rate

- Preferred method post partum

- Must be taken at same/similar time each day

-  Maximal effect 2-3hrs post ingestion

-  Reduced effect by 21hrs

 

Mechanism

- Increased viscosity of cervical mucus to impede sperm penetration

- Effect on endometrium to unsuitable for implantation

 

Indications

- Contraception

-  Post partum esp if breast feeding

-  Contraindications for COC

 

Side Effects

- Irregular periods

- No effect on

-  Blood pressure (HTN)

-  Risk of DVT, PE

 

Contraindications

- Breast Ca

- Undiagnosed vaginal bleeding

- Thromboembolic disease: AMI..

- Relative contraindications

-  Active viral hepatitis

-  Severe chronic liver disease

-  Anticonvulsants reduce contraceptive effectiveness

-  Advised to take double daily dose

 

Types

- Levonorgestrel 30mcg PO Daily

- Norethisterone (Micronur) 350mcg PO Daily

 

Mx

- Commenced on first day of menstrual cycle & taken continuously

- If missed pill or diarrhoea/vomiting within 2hrs of ingestion

-  Take as soon as known

-  Additional contraceptive method for 48hrs

-  Consider emergency contraception

 

 

 

References

 

Australian Prescriber: Progestogen only methods of contraception, www.australianprescriber.com/magazine/22/1/6/8