Respiratory Pharmacology

Question 1

what is the MOA of prostanoids?

Answer 1

Mimic prostacyclin -> vasodilation, suppress smooth Ms growth, inhibit platlet aggregation

Question 2

what is the MOA of bosentan?

Answer 2

nonspecific block ETa & ETb endothelin receptors on smooth Ms.

Question 3

what is the MOA of Ambrisentan?

Answer 3

block ETa

Question 4

what is the role of ETa receptor?

Answer 4

vasoconstriction & cell proliferation

Question 5

what is the MOA of macitentan?

Answer 5

ET1 antagonist on both ETa & ETb

Question 6

what is the MOA of sildenafil & tadalafil?

Answer 6

PDE-5 inhibitor

Question 7

what is the MOA of riociguat?

Answer 7

soluble guanylate cyclase stimulator

Question 8

what medications would be used to improve exercise intolerance in patients with PAH?

Answer 8

Epoprostenol, Treprosinil, Iloprost, Bosentan, Ambrisentan, Sildenafil, Riociguat

Question 9

A patient was recently started on a new prescription to treat their pulmonary arterial hypertension. They have started feeling dizzy and malaised. Vitals shows a BP of 100/75 and patient says they have had pain around their jaw for the last week. What medications & class was this patient most likely put on?

Answer 9

Epoprostenol, Treprostinil, Selexipag - Prostanoids

Question 10

A patient has been on a drug to treat their PAH for the last several months but has noticed confusion, loss of appetite, nausea, vomiting, and vision distortions. Looking at her drug list she is on a drug to treat her chronic AFIB. What is the most likely drug she is on for PAH causing these effects?

Answer 10

Epoprostenol, she is showing signs of digoxin toxicity used to treat her chronic AFIB.

Question 11

What drug interactions should be avoided when prescribing a patient prostanoids?

Answer 11

antihypertensives, diuretics, vasodilators, anti-platlets, & anticoagulants

Question 12

Patient tells you they recently began taking a prostanoid for their PAH but feel like it is working “too well”. You see they are also on TMP-SMZ (a CYP2C8 inhibitor). What PAH drugs would most likely have been used?

Answer 12

Selexipag or Treprostinil

Both will have enhanced effects in the presence of a CYP2C8 inhibitor.

Question 13

What is a risk when giving Treprostinil via a central venous catheter?

Answer 13

blood infection or sepsis

Question 14

What are important risks to beware of when administering Iloprost?

Answer 14

Syncope from hypotension, Pulmonary venous hypertension (edema), bronchospasm (hypersensitivity)

Question 15

A patient comes in with pulmonary-veno-occlusive disease, what are they at risk of getting if given treatment with ANY PAH drug?

Answer 15

pulmonary edema

Question 16

when would using bosentan be contraindicated?

Answer 16

liver disease (hepatotoxic), pregnancy (feto-toxic), Cyclosporine A, Glyburide, allergy

Question 17

giving a patient bosentan has risk of what side-effects?

Answer 17

respiratory infection & anemia (coated)

URI & fever (uncoated)

Question 18

what drug interactions are likely with bosentan?

Answer 18

CYP2C9 & CYP3A4 or OCP

Question 19

What combination therapy would be indicated for prevention of progression & hospitalization in PAH?

Answer 19

Tadalafil + Ambrisentan

Question 20

What is the most significant risk associated with endothelin anatagonists in treatment of PAH?

Answer 20

Embryo-fetal toxicity, hepatotoxicity, low Hgb, pulmonary edema, fluid retention

Question 21

What are CYP3A4 inhibitors?

Answer 21

Ketoconazole & Ritonavir

Question 22

What are CYP3A4 inducers?

Answer 22

Rifampin

Question 23

What drugs should be avoided when prescriping Macitentan?

Answer 23

CYP3A4 inhibitors & inducers

Question 24

What are likely side-effects in Ambrisentan alone? with Taldalafil?

Answer 24

alone: nasal congestion, sinusitis, flushing
combo: peripheral edema, congestion, bronchitis, anemia

Question 25

what are likely side-effects in macitentan?

Answer 25

nasopharyngitis, flu, UTI, bronchitis

Question 26

What drug should avoided when administering PDE-5 inhibitors?

Answer 26

alpha blockers, amlodipine, ritonavir, other PDE-5 inhibitors

Question 27

what side-effects are likely with PDE-5 inhibitors?

Answer 27

nose bleeds, rhinitis, dyspnea, insomnia, dyspepsia

Question 28

A patient comes in with chronic thromboembolic pulmonary hypertension, what would be the most appropriate therapy to improve exercise capacity?

Answer 28

Riociguat

Question 29

avoid co-administering riociguat with what other drugs?

Answer 29

CYP & P-gp/BCRP inhibitors, or antacids

if antacid, delay 1h after stopping

Question 30

contraindications for using riociguat are

Answer 30

pregnancy, nitrates or NO, PDE inhibitors, hypertension from interstitial pneumonia