From the Guidelines
Amlodipine can modestly lower pulmonary pressures in some patients with pulmonary hypertension, though it is not a first-line treatment for this condition. As a calcium channel blocker, amlodipine works by relaxing blood vessels throughout the body, including those in the lungs, which can reduce resistance and pressure in the pulmonary circulation 1. The effect is typically more pronounced in patients with pulmonary arterial hypertension who demonstrate vasoreactivity during acute vasodilator testing. For these patients, doses typically start at 2.5 mg daily and may be titrated up to 10-20 mg daily based on response and tolerability. However, the pulmonary pressure-lowering effects of amlodipine are generally less significant than those of medications specifically approved for pulmonary hypertension, such as phosphodiesterase-5 inhibitors, endothelin receptor antagonists, or prostacyclins.
Some key points to consider when using amlodipine for pulmonary hypertension include:
- The medication should be used under the guidance of a specialist who can determine the appropriate treatment strategy based on the specific type and severity of the condition 1.
- Side effects may include peripheral edema, headache, and dizziness.
- Amlodipine may be safe in patients with severe heart failure, as demonstrated in the PRAISE trial (Prospective Randomized Amlodipine Survival Evaluation) 1.
- Other calcium channel blockers, such as diltiazem and verapamil, should be avoided in patients with heart failure due to their negative inotropic properties 1.
Overall, while amlodipine can be used to lower pulmonary pressures in some patients with pulmonary hypertension, its use should be carefully considered and monitored by a specialist, and it should not be used as a first-line treatment for this condition 1.
From the Research
Amlodipine's Effect on Pulmonary Pressures
- Amlodipine has been shown to produce acute pulmonary vasodilatation in patients with pulmonary hypertension 2.
- In a study of six patients with pulmonary hypertension, amlodipine decreased mean pulmonary artery pressure and pulmonary vascular resistance by greater than 20% in two patients, and partially responded in one patient 2.
- The whole group mean pulmonary artery pressure decreased from 47.7 to 41.7 mm Hg and mean pulmonary vascular resistance from 8.6 to 7.1 Wood units 2.
- Amlodipine has also been compared to other calcium channel blockers, such as felodipine, in patients with pulmonary hypertension secondary to COPD, and has been shown to be effective in reducing pulmonary artery pressure and pulmonary vascular resistance 3.
- In patients with COPD and pulmonary hypertension, amlodipine has been shown to decrease pulmonary vascular resistance and pulmonary arterial pressure, and improve right heart function during exercise 4.
Mechanisms and Treatment Targets
- Pulmonary hypertension is a complex disease with multiple underlying mechanisms, including fibrosis, oxidative stress, and metabolic syndrome 5.
- Understanding these mechanisms could potentially provide novel therapeutic targets for the treatment of pulmonary hypertension 5.
- Amlodipine's mechanism of action as a calcium channel blocker may contribute to its effectiveness in reducing pulmonary pressures and improving right heart function 2, 3, 4.
Clinical Implications
- Amlodipine may be a useful treatment option for patients with pulmonary hypertension, particularly those with COPD or primary pulmonary hypertension 2, 3, 4.
- Further studies are needed to fully understand the effects of amlodipine on pulmonary pressures and to determine its potential as a treatment for pulmonary hypertension 2, 5.