Pulmonary arterial hypertension

Where it participates (unsigned role)

1. In ten patients with pulmonary hypertension either primary or related to previous left-to-right shunts, thromboembolism or interstitial lung disease and poorly controlled on conventional therapy, sildenafil 25 milligrams eight hourly for two weeks was associated compared with placebo with improved exercise tolerance on the six-minute walk test at 266.67 against 170 metres, a decrease in modified Borg dyspnea score from 5.11 to 3.56, a decrease in Doppler-estimated pulmonary artery systolic pressure from 75.33 to 55.33 millimetres of mercury, and improvement in New York Heart Association class in two patients, with no significant changes in heart rate or blood pressure.

   Sildenafil → Six-minute walk distance source_derived_draftungraded
   Experimental context and source evidence

   evidence_span

   {"source_cache": "artifacts/sildenafil-research/12760589.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "bca7bee4050068cd35e6f9f10a8de3c3a4505b4682eef9b8f91126ac1dbf38e5", "start_char": 0, "end_char": 2507, "text_sha256": "bca7bee4050068cd35e6f9f10a8de3c3a4505b4682eef9b8f91126ac1dbf38e5"}

   experimental_model

   Randomised double-blind placebo-controlled crossover trial in ten consecutive patients poorly controlled on conventional therapy

   exposure

   Sildenafil 25 milligrams every eight hours or matching placebo for two weeks each with a two-week run-in between

   limitations

   Ten patients of mixed aetiology, with pulmonary artery pressure estimated by echo Doppler rather than catheter, and a two-week exposure.

   nutrient_topic

   Sildenafil research collection; topical membership is not evidence of a direct clinical effect, and the drug is recorded separately from its N-desmethyl metabolite and its target enzyme from the homologous retinal PDE6. · Sildenafil

   organism

   Human

   plain_language

   Two weeks of tablets let these patients walk nearly a hundred metres further and dropped the pressure in the lung.

   primary_references

   [sil-p12760589] The efficacy and tolerability of sildenafil in patients with moderate-to-severe pulmonary hypertension. (2003). https://pubmed.ncbi.nlm.nih.gov/12760589/

   tissue_or_cell_type

   Pulmonary circulation

   Sildenafil: the enzyme it occupies instead of the substrate, why it cannot start a signal it can only preserve, the organic nitrate interaction that follows from that, the homologous retinal enzyme ten-fold away, and the pulmonary circulation where the same mechanism became a second indication (2026-09-22) · lines 574–585

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Randomised double-blind placebo-controlled crossover trial in ten consecutive patients poorly controlled on conventional therapy · source_derived_draft · unverified_draft

   ### sil-improves-walking-and-pressure In ten patients with pulmonary hypertension either primary or related to previous left-to-right shunts, thromboembolism or interstitial lung disease and poorly controlled on conventional therapy, sildenafil 25 milligrams eight hourly for two weeks was associated compared with placebo with improved exercise tolerance on the six-minute walk test at 266.67 against 170 metres, a decrease in modified Borg dyspnea score from 5.11 to 3.56, a decrease in Doppler-estimated pulmonary artery systolic pressure from 75.33 to 55.33 millimetres of mercury, and improvement in New York Heart Association class in two patients, with no significant changes in heart rate or blood pressure. Condition category: normal nutrient_topic: Sildenafil research collection; topical membership is not evidence of a direct clinical effect, and the drug is recorded separately from its N-desmethyl metabolite and its target enzyme from the homologous retinal PDE6. plain_language: Two weeks of tablets let these patients walk nearly a hundred metres further and dropped the pressure in the lung. organism: Human tissue_or_cell_type: Pulmonary circulation experimental_model: Randomised double-blind placebo-controlled crossover trial in ten consecutive patients poorly controlled on conventional therapy limitations: Ten patients of mixed aetiology, with pulmonary artery pressure estimated by echo Doppler rather than catheter, and a two-week exposure. exposure: Sildenafil 25 milligrams every eight hours or matching placebo for two weeks each with a two-week run-in between evidence_span: {"source_cache": "artifacts/sildenafil-research/12760589.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "bca7bee4050068cd35e6f9f10a8de3c3a4505b4682eef9b8f91126ac1dbf38e5", "start_char": 0, "end_char": 2507, "text_sha256": "bca7bee4050068cd35e6f9f10a8de3c3a4505b4682eef9b8f91126ac1dbf38e5"} [sil-p12760589] The efficacy and tolerability of sildenafil in patients with moderate-to-severe pulmonary hypertension. (2003). https://pubmed.ncbi.nlm.nih.gov/12760589/

   Complete structured claim and evidence