Pulmonary Hypertension Flashcards
Definition of Pulmonary Hypertension (PH)
A hemodynamic and pahtophysiological condition defined as: An increase in mean pulmonary arterial pressure >25 mmHg at rest as assessed by heart cath
Definition of Pulmonary Arterial Hypertension (PAH)
A clinical condition characterized by precapillary PH in the absence of other causes (lung disease, chronic thrombo-embolic PH)
Changes in these 2 things affect pulmonary blood flow
Cardiac Output and pleural/alveolar pressure
Drugs that definitely cause PAH
Aminorex, fenfluramine, dextenfluramine, toxic rapeseed oil, benfluorex
Drugs that are likely to cause PAH
Amphetamines, L-tryptophan, mephamphetamines
Drugs that are UNLIKELY to cause PAH
OC, estrogen, cigarettes
Drugs that possibly cause PAH
cocaine, phenylpropnolamine, St. John’s wort, chemotherapic agentis, SSRI, pergolide
WHO Class I
No symptoms with normal daily activities
WHO Class II
Symptoms with strenuous normal daily activities. Slightly limit functional status and activity level
WHO Class III
Symptoms of dyspnea, fatigue, syncope and chest pain with normal daily activities that severely limit functional status and activity level
WHO Class IV
Symptoms at rest, cannot conduct normal daily activities w/o symptoms
Risk factors for PAH
history of smoking/ ETOH/ recreational drug use, systemic htn, cyanosis/ murmur as a child, Joint/ musculoskeletal pain, Raynaud’s syndrome, previous DVT, use of appetite suppressant drugs
Clinical Presentation of PAH
Dyspnea on exertion (DOE), Fatigue, weakness, chest pain, syncope, LE or abdominal swelling
Evaluation of PH
ECG, Chest x-ray, PFT, exercise oximetry, echo, right heart cath w/ vasodilator testing, labs (CBC, CMP, INR, ANA, HIV, TFTs)
Reassessment of PAH
functional class determination and 6 minute walk test every 3-6 months
Treatment of PAH (5 basics)
- Supportive care
- Oxygen
- Oral anticoagulation
- Immunizations
- Birth control
Supportive care for PAH
Treat hypoxemia, avoid dehydration, pain fatigue, high altitude, smoking, pregnancy and iron deficiency
Oxygen for PAH
Maintain O2 sat above 90% use a diuretic if peripheral edema or ascites
Oral Anticoag for PAH
Warfarin (INR 1.5-2.5) +/- digoxin, +/- diuretics (anticoag to prevent catheter thrombosis and VTE)
Immunizations for PAH
Flu and pneumococcus
CCB use in PAH
Class II PAH (should not be used empirically without positive response to acute vasodilatory response testing)
Selecting a CCB
If tachycardic (>90) use diltiazem; if bradycardic choose amlodipine or nifedipine
Endothelin’s role in PH
exerts vasoconstrictor mitogenic effects by binding to 2 distinct receptor isoforms in the pulmonary vascular smooth muscle cells Endothelin A and B receptors
Bosentan (Trade name, class, Indication, dose)
Tracleer, Nonselective ETa and ETb receptor blocker, Class III and IV PAH, 62.5-125 mg PO BID
Bosentan Considerations
Severe interaction with glyburide and cyclosporine, potential teratogen (use 2 forms of birth control)
Monitering paramaters with Bosentan
Monitor LFTs monthly, Monitor hemoglobin/ hematocrit every 3 months, pregnancy test monthly
Ambrisentan (Trade, Class, Indication, Dose)
Letairis, ETa blocker, Class II or III PAH, 5-10 PO QD
Considerations with Ambrisentan
Caution with cyclosporine, Monitor LFTs monthly, potential teratogen
Macitentan (Trade, Class, Indication, Dose)
Opsumit, Nonselective ETa and ETb blocker, PAH (maybe class III?), 10 mg PO QD
Macitentan Considerations
Pregnancy precautions (REMS program), may cause severe anemia, Hepatotoxicity may occur, PVOD may occur
PDE-5 Inhibitors
Enhance NO-cGMP pathway, slowing cGMP degradation
sGC Stimulators
Enhance cGMP production and are potentially effective also in conditions in which endogenous NO is depleted
Riociguat (Trade, Class, Indication, Dose)
Adempas, sGC stimulator, CTEPH (WHO group 4), 1mg PO QD)
Riociguat Considerations
Pregnancy precautions, Renal impairment, Hepatic impairment
Sildenafil (Trade, Class, Indication, Dose)
Revatio, PDE-5i, Class II-IV PAH, 20 mg PO TID
CI of Sildenafil and Tadalafil
CI in patients using nitrates
Tadalafil (Trade, Class, Indication, Dose)
(Adcirca, PDE-5i, Class II-IV PAH, 40mg PO QD)
Prostacyclin Pathway
Produced by endothelial cells, induces vasodilation, inhibits platelet aggregation, dysregulation of prostacyclin shown in pts with PAH
Eprostenol (trade, class, indication, dose)
Flolan + Veletri, prostanoid, Class III-IV, 2-40 mg/kg/min IV
Eprostenol Considerations
Considered a medical emergency if infusion interrupted (spare drug cassette and infusion pump should be kept available)
Treprostinil (Trade, class, Indication, dose)
Remodulin + Tyvaso, Prostanoid, Class II-IV PAH, 1.25-40 ng/kg/min IV
Treprostinil ADE
Severe erythema (83%) and injection site pain (85%) (have hot/cold packs and topical analgesics available) (move infusion site every 3 days)
Inhaled iloprost (Trade, Class, Indication, dose)
Ventavis, Prostanoid, Class III-IV, 5 mcg by nebulizer 6-9 times a day
