Pulm: Drugs to Treat Pulmonary HTN Flashcards
WHO Class I-IV of Pulmonary HTN:
I: pHTN w/o limitations
II: pHTN w slight limitation
III: pHTN w marked limitation
IV: pHTN w inability to carry out any physical activity
When would you use dihydropyridine CCBs for pHTN?
If they have a positive vasopressor test
-if negative, they may have adverse effects
What three treatments are used in pHTN that have very little impact on the hypertension itself?
Anticoagulants-to prevent thrombi
Diuretics-for R HF
Oxygen
MOA of prostanoids (contain PROST)?
Mimics the actions of prostacyclin, binds Gs=increase cAMP
- vascular relaxation
- suppresses growth of smooth muscle
- inhibits platelet aggregation
Effects of prostinoids on pHTN?
Lowers pulmonary artery resistance and pressure, increases exercise tolerance, and improves short term survival
Adverse effects of Prostinoids?
If given IV (epoprostenol and treprostinil):
Sepsis through catheter, life treatening if pump is clogged
Others: nausea, headache, flushing
Which prostanoid is given subQ?
Treprostinil
-painful!
What is special about treprostinil’s ROA?
Longer half life and no refrigeration
Lots of Routes!
-SubQ, QID Inhalation, and extended release oral form available
Which drugs are the prostinoids?
EpoPROSTenol, TrePROSTinil, iloPROST, Selexipag
Which prostinoid is only inhaled?
Iloprost
Which prostinoid is administered orally, BID?
Selexipag
-very expensive
What are the two endothelin antagonists?
Bosentan and Ambrisentan
-sentan!
Which endothelin antagonist is nonspecific at the ETa and ETb receptors? Which one is specific?
Bosentan is nonspecific, while ambrisentan is specific
Effects of the endothelin antagonists?
Reduce the amount of vasoconstriction and improves exercise intolerance in pHTN
Which of the endothelin antagonists interacts with warfarin and oral contraceptives?
Bosentan
-accelerates metabolism of both warfarin and oral contraceptives
Which of the endothelin antagnists is teratogenic? What about hepatotoxic?
Teratogenic=Bosentan and Ambrisentan
Hepatotoxic=Bosentan only
which drugs are PDE-5 antagonists?
Sildenafil and tadalafil
What are the effects of the PDE-5 antagonists?
Prevent breakdown of cGMP, so relax smooth muscle
-Improve exercise intolerance and slow symptoms in pHTN
Which PDE-5 antagonists has a longer half life, Sildenafil or tadalafil?
Tadalafil
MOA of Riociguat? (3)
Sensitizes soluble guanylate cyclase (sGC) to NO
-stabilizes the binding
Directly stimulates sGC
Increases generation of cGMP=vasodilation
Adverse effects of Riociguat?
Hypotension, headache, dizziness, and dyspepsia
-possible severe bleeds and fetal harm
Should you take riociguat while pregnant?
Nope
Tx for pt with class II or III pHTN and no disease progression, who is willing to take combined therapy?
Ambrisentan and tadalafil
Tx for pt with class II and III pHTN, with NO disease progression and wants monotherapy?
Endothelin Antag: Macitentan, ambisentan
Guanylate Cyclase sensitizer: riociguat
PDE-5 blockers: sildenafil, tadalafil
If pt has class III pHTN w disease progression or class IV pHTN, what should you use to treat?
A Prostinoid
- IV Epoprostenol
- IV or SubQ Treoprostinil
If pt has class IV pHTN and is not willing to take do IV prostanoids, what should you give?
Inhaled prostanoid+oral PDE-5 (-fil) and oral ET-antagonist
If a pt with class IV pHTN is treated with a a prostinoid and is still unresponsive, what should you do?
Add a second or even third class!
-after that, list for lung transplant
most common combo of drugs used to treat pHTN?
Tadalafil + ambrisentan
