Adempas, as a targeted therapy for pulmonary arterial hypertension, has clear indications and strict adherence to medication precautions. The following provides a detailed explanation from two aspects: the scope of indications and medication precautions, in order to provide guidance for rational clinical drug use.

1. Scope of indications

(1) Chronic thromboembolic pulmonary hypertension (CTEPH): Suitable for WHO functional class II-III patients who cannot undergo surgery or have persistent/recurrent CTEPH after surgery, it can improve 6-minute walking distance and hemodynamic parameters.

(2) Pulmonary arterial hypertension (PAH): Used for WHO functional class II-III patients with idiopathic/hereditary PAH, connective tissue disease-related PAH, or congenital heart disease-related PAH, to delay clinical progression.

2. Medication precautions

(1) Contraindications

Prohibited during pregnancy (teratogenic risk); Combined use with nitrate esters or PDE5 inhibitors can cause life-threatening hypotension; Avoid use for severe liver dysfunction.

(2) Dose adjustment

The initial dose is 0.5mg, increasing by 0.5mg every 2 weeks until the maintenance dose is 1.5-2.5mg; When hemoglobin is less than 8g/dL or systolic blood pressure is less than 95mmHg, administration should be suspended.

(3) Monitoring requirements

Before treatment, it is necessary to confirm the pregnancy status; Monthly monitoring of hemoglobin (anemia risk); Regularly assess liver function; Smokers need to monitor efficacy more frequently.

(4) Special populations

Starting from the lowest dose for elderly patients; The maximum dose for patients with moderate to severe liver damage should not exceed 1.5 mg/tid; Breastfeeding should be stopped during lactation.

3. Restrictive conditions

(1) Blood pressure restriction: Patients with systolic blood pressure<95mmHg or symptomatic hypotension are prohibited from using it. Regular monitoring of blood pressure changes is required during treatment.

(2) Hemoglobin restriction: If the baseline value is less than 8g/dL or falls below this threshold during treatment, medication should be suspended until it returns to ≥ 8g/dL.

(3) Smoking restrictions: Nicotine can reduce drug exposure by 25%, dosage adjustments should be considered or smoking cessation is strongly recommended.