Conference: 2018 PHA International PH Conference & Scientific Sessions
Release Date: 06.28.2018
Presentation Type: Abstracts
File Download: Conference 2018_1073
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Abstract presented at the 2018 International PH Conference and Scientific Sessions in Orlando, Fla., June 28-July 1, 2018.
Describe the experience of one patient transitioned from subcutaneous (SC) treprostinil to oral treprostinil at home.
Pulmonary arterial hypertension (PAH) is a rare disease that is characterized by elevated pressures in the pulmonary arteries that result in vascular remodeling and right heart failure. Treatment strategies are geared towards physiologic pathways that are up or down regulated. Oral agents such as phosphodiesterase type 5 inhibitors, endothelin receptor antagonists and soluble guanylate cyclase stimulator are often used in combination as first line agents. Parenteral prostacyclin is usually reserved for patients with advanced disease. Parenteral prostacyclin medications though they have clear benefit are often burdensome with risk related to route of administration such as infection with intravenous (IV) route or site pain with SC route of administration. Side effects from this class of drug can be intolerable and thus may slow up-titration or limit optimal dosing. Orenitram® (treprostinil), an oral prostacyclin was FDA approved in 2002 for the treatment of WHO Group 1 PAH to improve exercise capacity. There are no data from randomized clinical trials on transitioning patients from parenteral to oral prostacyclin therapy. Information is obtained through multicenter open label study, retrospective analyses, case series and case report. Review of these data revealed variable results with typical transition occurring over 4 - 5 days in a hospital setting.
56-year-old man with WHO group 1 PAH on SC treprostinil at 40 ng/kg/min requested to be transitioned as an outpatient to oral treprostinil due to SC site pain and ease of an oral drug administration. He was clinically stable with New York Heart Association Functional Class II symptoms with an average 6-minute walk distance (6MWD) of 385 meters. Right heart catheterization obtained prior to the transition showed pulmonary artery mean pressure of 28 mmHg, normal cardiac index and pulmonary artery saturation. Based on his body weight of 98.5 kg the comparable dose of oral treprostinil was calculated to be 28 mg daily or approximately 9 mg three times daily. Oral treprostinil was initiated at 1 mg three times daily (TID) and at the same time SC treprostinil was decreased by 6 ng/kg/min. Weekly dosing titration schedule included decreasing SC treprostinil by 6 ng/kg/min as oral treprostinil was increased by 1 mg TID to an initial goal of 7 mg TID over a seven-week period. Patient was monitored closely with coordinated visits between Pulmonary Hypertension Nurse Practitioner and Specialty Pharmacy RN visits.
Subcutaneous treprostinil was discontinued when patient was on oral treprostinil 7 mg TID. At this time, patient complained of exertional dyspnea in extreme cold weather and had evidence of fluid retention. His diuretic dose requirement was increased and oral treprostinil was further up-titrated over another 3 weeks to a goal dose of 10 mg TID. At this dose, patient was back to his baseline breathing and exercise tolerance and his 6MWD remained stable. Patient did not experience any increased prostacyclin side effects and was otherwise clinically stable during the entire transition process.
The initial goal dose of oral treprostinil 7 mg TID was underestimated due to the patient near normal pulmonary pressures prior to the transition. This was a successful and seamless transition from SC treprostinil to oral treprostinil. The current data available occurs in the hospital setting. Based on this one patient encounter, it may be safe to do a slow transition at home on a case by case basis.