title: Addition of sildenafil to bosentan monotherapy in pulmonary arterial hypertension.
abstract: Combination therapy has been recommended for the treatment of pulmonary arterial hypertension (PAH). However, there is scant information on combination therapy after failure of monotherapy, particularly in patients with scleroderma-associated PAH (PAH-SSD). From a group of 82 consecutive patients with PAH who received initial bosentan monotherapy, a total of 13 idiopathic PAH (IPAH) and 12 PAH-SSD patients requiring additional therapy with sildenafil were studied. Sildenafil was added for clinical deterioration based upon symptoms, New York Heart Association (NYHA) classification or 6-min walk distance (6MWD). Clinical data and haemodynamics were collected at baseline. Assessments were made at 1-3-month intervals. At baseline, there were no differences in demographics, NYHA classification, haemodynamics or 6MWD between the two groups. After initiation of bosentan, both groups experienced clinical improvement but ultimately deteriorated (median time to monotherapy failure 792 versus 458 days for IPAH and PAH-SSD patients, respectively). After addition of sildenafil, more IPAH patients tended to improve in NYHA class (five out of 13 versus two out of 12) and walked further (mean difference in 6MWD 47+/-77 m versus -7+/-40 m) compared with PAH-SSD patients. In conclusion, addition of sildenafil after bosentan monotherapy failure improved New York Heart Association class and 6-min walk distance in idiopathic pulmonary arterial hypertension patients but failed to improve either parameter in scleroderma-associated pulmonary arterial hypertension patients. Additional studies are needed to assess the tolerability and efficacy of this combination in patients with scleroderma-associated pulmonary arterial hypertension.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, 1830 East Monument Street, 5th Floor, Baltimore, MD 21205, USA.
authors.forename: S C
authors.initials: SC
authors.lastname: Mathai
authors.forename: R E
authors.initials: RE
authors.lastname: Girgis
authors.forename: M R
authors.initials: MR
authors.lastname: Fisher
authors.forename: H C
authors.initials: HC
authors.lastname: Champion
authors.forename: T
authors.initials: T
authors.lastname: Housten-Harris
authors.forename: A
authors.initials: A
authors.lastname: Zaiman
authors.forename: P M
authors.initials: PM
authors.lastname: Hassoun
mesh_terms: D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000009:adverse effects / Q000627:therapeutic use*; D000077300:Bosentan; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D005080:Exercise Test / Q000187:drug effects; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy*; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000009:adverse effects / Q000627:therapeutic use*; D011669:Pulmonary Wedge Pressure / Q000187:drug effects; D011687:Purines / Q000009:adverse effects / Q000627:therapeutic use; D012595:Scleroderma, Systemic / Q000150:complications / Q000188:drug therapy; D000068677:Sildenafil Citrate; D013449:Sulfonamides / Q000009:adverse effects / Q000627:therapeutic use*; D013450:Sulfones / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D014665:Vasodilator Agents / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D000959:Antihypertensive Agents; D010879:Piperazines; D011687:Purines; D013449:Sulfonamides; D013450:Sulfones; D014665:Vasodilator Agents; D000068677:Sildenafil Citrate; D000077300:Bosentan