Therapy of pulmonary hypertension: targeting pathogenic mechanisms with selective treatment delivery

The response to inhaled nitric oxide in patients with pulmonary artery hypertension is not masked by baseline vasodilator use

BACKGROUND

Assessment of pulmonary vasodilator responsiveness is important in determining the prognosis and management of patients with pulmonary hypertension. Many patients, however, are already on vasodilators at the time of testing. It is unclear if these agents should be temporarily discontinued to improve the sensitivity of testing.

METHODS

We examined the hemodynamic effects of nitric oxide (NO) inhalation in 60 patients with pulmonary arterial hypertension. Thirty-one of these patients were receiving medications with vasodilating properties. Vasodilator testing was performed with invasive measurement of pressure of the right side of the heart at baseline and during inhalation of 40 ppm NO.

RESULTS

No significant demographic differences were seen between patients receiving and not receiving vasodilators. Similar reductions in mean pulmonary artery pressure (19 +/- 12% vs 20 +/- 12%, P = .734) and pulmonary vascular resistance (31 +/- 18 vs 32 +/- 16, P = .967) were seen in patients receiving and not receiving vasodilators. Using the definition of positive vasodilator response (> or = 20% drop in mean pulmonary artery pressure), 55% (17/31) of patients in the baseline vasodilator group had a positive response compared with 62% (18/29) of the patients not on vasodilators (P = .570).

CONCLUSIONS

Concurrent use of oral vasodilators does not appear to mask a significant response to inhaled NO on the pulmonary vasculature. Therefore, routine discontinuation of pulmonary vasodilators is likely unnecessary before vasodilator testing in patients with pulmonary arterial hypertension.

Tadalafil: Pulmonary Hypertension (Adults)

Off-Label Drug Uses

This Hospital Pharmacy feature is extracted from Off-Label DrugFacts, a quarterly publication available from Facts and Comparisons. Off-Label DrugFacts is a practitioner-oriented resource for information about specific FDA-unapproved drug uses. This new guide to the literature will enable the health care professional/clinician to quickly identify published studies on off-label uses and to determine if a specific use is rational in a patient care scenario. The most relevant data are provided in tabular form so that the reader can easily identify the scope of information available. A summary of the data—including background, study design, patient population, dosage information, therapy duration, results, safety, and therapeutic considerations—precedes each table of published studies. References direct the reader to the full literature for more comprehensive information prior to patient care decisions. Direct questions or comments on “Off-Label Drug Uses” to hospitalpharmacy@drugfacts.com .

Infant pertussis deaths and the management of cardiovascular compromise

Infants infected with Bordetella pertussis in the first few weeks of life are at risk of death from 'overwhelming cardiovascular compromise despite intensive care support'. The mechanisms of this severe disease are not completely understood. Three case histories, including that of one infant who survived, are presented. Two of the patients died despite intensive therapy with pressors and, in one child, milrinone. The third child survived following treatment with nitric oxide and sildenafil. Hence, sildenafil in combination with nitric oxide shows promise as a therapy for the haemodynamic consequences of pertussis toxaemia and this should prompt clinical trials for their efficacy for this condition.

Sildenafil: Pulmonary Hypertension (Pediatric, Neonatal)

Off-Label Drug Uses- This Hospital Pharmacy feature is extracted from Off-Label DrugFacts, a quarterly publication available from Facts and Comparisons. Off-Label DrugFacts is a practitioner-oriented resource for information about specific FDA-unapproved drug uses. This new guide to the literature will enable the health care professional/clinician to quickly identify published studies on off-label uses and to determine if a specific use is rational in a patient care scenario. The most relevant data are provided in tabular form so that the reader can easily identify the scope of information available. A summary of the data—including, background, study design, patient population, dosage information, therapy duration, results, safety, and therapeutic considerations—precedes each table of published studies. References direct the reader to the full literature for more comprehensive information prior to patient care decisions. Direct questions or comments on “Off-Label Drug Uses” to hospitalpharmacy@drugfacts.com .

[Sildenafil in the treatment of pulmonary hypertension]

Pulmonary hypertension (PHT) is a rare entity that is difficult to treat. Prognosis is poor. Sildenafil, a selective inhibitor of type 5 phosphodiesterase, has been proposed among the many treatments available for primary and secondary pulmonary hypertension. We report our experience with an infant with pulmonary hypertension due to congenital mitral stenosis and persistent ductus arteriosus, who developed congestive cardiac failure with persistent PHT despite surgical correction. Conventional treatment was unsuccessful and the patient was treated with sildenafil. The clinical course was satisfactory, allowing extubation and withdrawal of vasoactive drugs; pulmonary and left atrial pressure decreased and the patient was discharged. She is currently being treated on an outpatient basis with oral sildenafil and shows satisfactory hemodynamic status. We review alternatives to conventional treatments for pulmonary hypertension with special reference to pediatrics.