Contraception and anti-retroviral drug interactions

Question 1

what does NRTI stand for

Answer 1

Nucleoside reverse transcriptase inhibitors

Question 2

what is the MOA of NRTI

Answer 2

NRTI bind to the receptors of reverse transcriptase preventing reverse transcription from being able to take place this therefore prevents viral RNA being transcribed into DNA and thus viral replication

Question 3

Tenofovir disoproxil, Tenofovir alfenamide, emtricitabine, abacavir, lamvuidine, zidovudine are examples of which class of ARTs

A - NNRTI
B- protease inhibitors
C- intergrase inhibitors
D - NRTI

Answer 3

D - NRTI

Question 4

Zidovuidine belongs to which class of ART

A - NNRTI
B- protease inhibitors
C- intergrase inhibitors
D - NRTI

Answer 4

d - nrti

Question 5

abacavir belongs to which class of ART

A - NNRTI
B- protease inhibitors
C- intergrase inhibitors
D - NRTI

Answer 5

d - nrti

Question 6

effavirenz belongs to which class of ART

A - NNRTI
B- protease inhibitors
C- intergrase inhibitors
D - NRTI

Answer 6

A - NNRTI (non nucleoside reverse transcriptase inhibitors)

Question 7

what is the mode of action of NNRTI (non nucleoside reverse transcriptase inhibitors)

Answer 7

NNRTI work by binding to the reverse transcriptase enzyme (but not the receptor like NRTI) this causes the receptor to change shape meaning that HIV RNA can not bind halting viral replication

Question 8

Rilpvirine, nevirapine, Etravirine and Doravarine are examples of which class of ART

A - NNRTI
B- protease inhibitors
C- intergrase inhibitors
D - NRTI

Answer 8

A - NNRTI

Question 9

Name two intergrase inhibitors

Answer 9

Dolutegravir, Bictegravir

Intergrase inhibitors end in ‘gravir’

Question 10

what is the mode of action of intergrase inhibitors

Answer 10

intergrase inhibitors block the action of the enzyme intergrase which works to integrate HIV DNA into host DNA

Question 11

Bictegravir, dolutegravir, elvitegravir, raltegravir and cabotegravir are all examples of which class of ART

A - NNRTI
B- protease inhibitors
C- intergrase inhibitors
D - NRTI

Answer 11

C - intergrase inhibitors

Question 12

which class of ART block the ability of HIV to bind to CD4 T cell receptors

Answer 12

Entry inhibitors

Question 13

can you name an example of an entry inhibitor

Answer 13

Maraviroc

Question 14

what are the two types of entry inhibitor ART

Answer 14

CCR5 inhibitors
fusion inhibiors

Question 15

which receptor does Maraviroc act on

Answer 15

CCR5

Question 16

what is the mode of action of protease inhibitors

Answer 16

block the enzyme protease (HIV uses protease to break up large polyproteins into smaller pieces required for viral particle assembly)

Question 17

Atazanavir, Darunavir, Lopinavir are all examples of which class of ART

A - NNRTI
B- protease inhibitors
C- intergrase inhibitors
D - NRTI

Answer 17

B - protease inhibitors

Question 18

Enfuvitiride is an example of which class of ART

A - fusion inhibitor
B- protease inhibitors
C- intergrase inhibitors
D - NRTI

Answer 18

A - fusion inhibitor

Question 19

what is the mode of action of boosted drugs used in ART

Answer 19

boosted drugs aim to boost the effectiveness of protease inhibitors, it makes the liver break down protease inhibitors slower which means the body is exposed to higher levels of serum ART. Without the booster drug the prescribed drug would not be effective

Question 20

Ritonavir and cobicistat are examples of which class of ART

A - NNRTI
B- protease inhibitors
C- intergrase inhibitors
D - NRTI
E- boosted drugs

Answer 20

E- boosted drugs

Question 21

what type of virus is HIV

• single stranded DNA
  -single stranded RNA
  -double stranded DNA
  -single stranded RNA

Answer 21

single stranded RNA virus

Question 22

what class of viruses does HIV belong to

Answer 22

lentivirus

Question 23

name the ART that interacts with all forms of hormonal contraception excluding IUD (IUS/IUCD) and depo

Answer 23

Efavirenz

Question 24

what is Efavirenz effect on emergency contraception

Answer 24

Efavirenz is an enzyme inducer potential to decrease plasma level of levonorgestrel and ulipristal acetate

Question 25

ART efficacy is effected by contraception drug interactions - true or false

Answer 25

false - no evidence that any contraception effects the efficacy of ART. It is the reverse that ARTs can reduce the efficacy of contraception methods

Question 26

which two classes of ART are considered inducers of the P450 system

Answer 26

ritonavir boosted protease inhibitors and NNRTIs (specifically Efavirenz) (inducers speed up metabolism of contraception and therefore decrease its efficacy)

Question 27

NRTIs are considered safe will all forms of hormonal contraception (excluding oral EC) True or false

Answer 27

true

Question 28

which NNRTI should we avoid using hormonal contraception (oral EC, POP/CHC, implant) with and why

Answer 28

Efavirenz is a enzyme inducer of P450 system and should be avoided with all forms of hormonal contraception including oral EC

Question 29

what methods of contraception are considered safe with Effavirenz

Answer 29

IUS, IUCD, depo provera

Question 30

Are etravirine and nevirapine considered enzyme inducers or inhibitors of P450 system

Answer 30

enzyme inducers, potential weak interaction but not expected to lower HC effectiveness. FSRH advise to consider different option but could be used if patient understands potential risk as not considered to

Question 31

which two NNRTIs are considered safe with all forms of hormonal contraception

Answer 31

Doravirine and rilpivirine

Question 32

intergrase inhibitors are considered safe with all forms of contraception True or false

Answer 32

True e.g. dolutegravir, raltegravir, bictegravir

Question 33

what effect do boosted protease inhibitors have on hormonal contraception

Answer 33

increase in progestogen levels and EE levels remain unchanged or slightly decreased

Question 34

what is the advice regarding patients using enzyme inducing ART with emergency contraception

Answer 34

ideally avoid oral EC and advice EC-IUD as best option no evidence of double dosing ART if IUCD is not an option for the patient suggest double dose levonorgestrel but not to double dose ulipristal acetate (no evidence on how effective this is)

Question 35

what is the risk of of HIV acquisition from one episode of receptive vaginal sex with a partner known to be HIV positive with detectable viral load?

Answer 35

0.1%

Question 36

what type of sex has the highest risk of HIV acquisition

Answer 36

receptive anal sex (1.11%)

Question 37

Sally is a 32 year old female diagnosed with HIV and taking ART. Her HIV viral load is undetectable. She wants advice regarding contraception. She tells you her ART consists of efavirenz with tenofovir disoproxil. Which of the following is the most suitable form of contraception. A- IUS B- Implant C- CHC D- POP

Answer 37

A - IUS (Efavirenz is an enzyme inducer and therefore should be avoided with hormonal contraception except IUS/cu - IUD and depo

Question 38

boosted PI with carbocistat has the following effect on hormonal contraception A - increases estradiol and progestogen levels B- increased estradiol and decreases progestogen levels C- decreases estradiol and progestogen levels D- decreases estradiol and increases progestogen levels

Answer 38

A - increases estradiol and progestogen levels (hence FSRH recommend considering not using CHC due to potential theoretical increase in thrombosis risk) cobocistat is an inhibitor - inhibits metabolism of EE and P

Question 39

what does contraception efficacy rely on progestogen or oestrogen?

Answer 39

Progestogen exposure

Question 40

list the anti-retrovirals that should be avoided with hormonal EC and why

Answer 40

Efavirenz - enzyme inducer Etravarine - enzyme inducer Neviparine - enzyme inducer

Question 41

Can boosted PIs be used with oral EC (e.g. ritonavir and carbocistat boosted (atanzavir, darunavir, lopinavir)

Answer 41

yes fine with oral EC as if anything they lead to increased serum progestogen levels so don't decrease efficacy of oral EC

Question 42

protease inhibitors are enzyme inducers or inhibitors of Cytochrome P450 enzyme

Answer 42

inhibitors therefore lead to increased levels of serum hormones in contraception

Question 43

booster PIs are enzyme inducers or inhibitors of cytochrome P450 enzyme

Answer 43

inducers

Question 44

carbocistat an inducer or inhibitor of P450

Answer 44

inhibits - leads to increased levels of estradiol and progestogen (theoretical increase risk of thrombosis)

Question 45

is ritonavir an inducer or inhibitor of P450

Answer 45

both - it induces metabolism of EE and decreases metabolism of P therefore unlikely to affect hormonal contraceptive effectiveness, just perhaps a few more se due to low oestrogen e.g. irregular bleeding.