contraceptive interactions

Question 1

what drugs reduce the efficacy of hormonal contraceptives

Answer 1

carbemazepine
nevirapine
oxecarbazepine
phenytoin
phenobarbital 
primidone
ritoniver 
topiramate
rifabutin
rifampicin
griseofulvin 

by inducing hepatic enzyme activity

Question 2

patches, vaginal rings , oral tablets should switch to what if taking enzyme inducers

Answer 2

IUD or parenteral progesterone only contraceptives for the duration of treatment and four weeks after stopping

Question 3

short course of enzyme inducer (2 months) with a COC

Answer 3

continue CHC method and with condoms for duration of treatment and four weeks after

Question 4

long term course(over 2 months) of enzyme inducer or a course of griseofulvin with a COC

Answer 4

use a monophasic COC and use either an extended or tricycling regimen for the duration of treatment and for four weeks after

use of contraceptive patches or vaginal rings not recommended

Question 5

long term courseover 2 months of rifampicin or rifabutin with a COC

Answer 5

alternative method of contraception such as an IUD continued four weeks after course completion

Question 6

short course of enzyme inducer (2 months) with a POP

Answer 6

continue method with use of condoms for duration of treatment and four weeks after

Question 7

IM norithersterone
IM/SC medroxyprogesterone
eteonogestrel implant

Answer 7

not affected :
IM norithersterone
IM/SC medroxyprogesterone

effected:
eteonogestrel implant
alternative method recommended
short course used in combination with condoms for duration and four weeks after

Question 8

Emergency contraception

Answer 8

levonorgestrel and ulipristal effected by inducers and griseofulvin for at least 4 weeks after stopping

Copper IUD offered instead

or
levonorgestrel dose increased

Question 9

progesterone and ulipristal interaction

Answer 9

progesterone is given 7 days before or 5 days after administration

Question 10

initiating hormonal contraception after taking ulipristal

Answer 10

do not newly initiate until 5 days after administration fo ulipristal

condoms should be used for this period

Question 11

restarting regular COC after administration of ulipristal.

Answer 11

can restart immediately

Question 12

restarting regular POP after administration of ulipristal.

Answer 12

wait until 6 days after to start