Drug Interactions and Pharmacokinetics

Question 1

Which drugs interact with acid reducing agents such as omeprazole or ranitidine

Answer 1

Atazanavir bioavailability is decreased by 62% when administered with these agents
Rilpiverine plasma concentrations are reduced when coadministered

Question 2

Which ARVs cannot be used with polyvalent cations such as iron, magnesium, calcium and aluminium and antacids

Answer 2

Integrase inhibitors

Question 3

When do you use TAF 10mg

Answer 3

In combinations with cobi or ritonavir as they inhibit intestinal P-gp

Question 4

CYP inducers

Answer 4

CRAP GPS
Carbamazepine
Rifampicin
Alcohol
Phenytoin
Griseofulvin
Phenobarbitone
Sulphonylureas

Question 5

CYP inhibitors

Answer 5

ODEVICES
Omeprazole
Disulfuram
Erythromycin
Valproate
Isoniazid
Ciprofloxacin
Cimetidine
Ethanol
Sulphonamides

Question 6

Which booster both can inhibit and induce

Answer 6

Ritonavir

Question 7

Maximal induction affect and resolution

Answer 7

10 days
Resolution depends on half life of inducer
Example Rifampicin and Midazolam

Question 8

Inhibitors onset and resolution

Answer 8

Rapid for both after starting and. Stopping drug example is midazolam and ritonavir

Question 9

What affect does administering DTG and metformin have

Answer 9

Increased systemic concentrations of metformin

Question 10

Which contraception can be used with efavirenz

Answer 10

Levonorgestrel IUD and Depo

All the rest significantly reduce EFV exposure

Question 11

Which ARVs need to be taken with food

Answer 11

Atazanavir/r/c
Darunavir/r/c
High dose lopinavir/r 800/100
Etravirine
Rilpivirine
Elvitegravir fixed dose combination
TDF-ideally

Question 12

Which ARV should be taken on an empty stomach

Answer 12

Efavirenz

Question 13

ARVs and drugs for gender affirmation

Answer 13

Ethinylestradiol only one not recommended due to thrombosis risk rest can be dose adjusted or monitored

Question 14

Flucloxacillin ARV interactions

Answer 14

At high doses it is a liver enzyme induced
Use with caution with
Boosted ARVs
Bictegravir
Doravirine
Maraviroc
Rilpiverine

Avoid with
Cabotegravir/rilpiverine
Lenacapavir

Question 15

Do not coadminister boosted PIs with the following drugs

Answer 15

Amiodarone
Rifampicin
Rifapentine
Apixaban
Clopidogrel
Rivaroxaban
Ticagrelor
Terfenidine
Oral midazolam
Domperidone
Eplerenone
Ivabradine
Lercanidipine
Sildenafil
St John’s wort
Red yeast rice
Budesonide
Fluticasone

Question 16

Do not coadminister NNRTIs with the following

Answer 16

Rifampicin/rifapentin (except dapivirine)
Carbamazepine
Phenytoin
St John’s wort

Question 17

Do not coadminister efavirenz with the following drugs

Answer 17

Isavuconazole
Ketoconazole
Midazolam
All contraceptives and HRT except levoIUD

Question 18

Do not administer Rilpiverine with the following drugs

Answer 18

Rifampicin/ Rifapentine
Carbamazepine
Phenytoin
Omeprazole
Pantoprazole
Dexamethasone >16mg

Question 19

Do not administer TAF with the following

Answer 19

Carbamazapine
Phenytoin
St John’s wort

Question 20

Do not use elvitegravir/C with the following medications

Answer 20

Amiodarone
Dronedarone
Rifampicin
Rifapentin
Apixaban
Clopidogrel
Rivaroxaban
Ticagrelor
Carbamazepine
Phenytoin
Isavuconazole
Midazolam
Simvastatin
Budesonide
Fluticasone
Sildenafil
Ivabradine
Eplerenone
Domperidone

Question 21

Do not administer Bictegravir with

Answer 21

Rifampicin
Rifapentin
Rifabutin
Carbamazapine
Phenytoin

Question 22

ARVs associated with dyslipidaemia

Answer 22

Boosted PIs
Elvitagravir boosted
Efavirenz