According to the results of a systematic literature review and metanalysis, patients with β-thalassemia who received the calcium channel blocker amlodipine in conjunction with chelation therapy did not show improvements in measures of iron overload relative to patients in the control groups. These findings were reported in a study published in Hemoglobin.
Following standardized literature review guidelines, the investigators identified 5 randomized clinical trials that included a total of 210 patients with follow-up durations of 3 to 12 months. Overall, female patients comprised 53% of the sample, and the mean age ranged from 10 to 31 years.
Pooled analysis revealed no significant difference between patients who received amlodipine and control groups in heart T2* magnetic resonance imaging (mean difference [MD], –1.9; 95% CI, -4.4 to 0.5, P = .119) or liver iron concentration (MD, -0.046; 95% CI, -0.325 to 0.2); P = .746).
No serious adverse events were reported in the trials, and 2 studies reported no adverse events. In studies that reported adverse events, they included abdominal upset (drug and control group, 13.5% and 23.5%), ankle swelling (6.7% and 4.7%), and dizziness (4.8% and 0.0%, respectively); cutaneous allergy was documented in 1 patient receiving amlodipine.
Limitations of the research included the small number of studies included and a lack of consistent patient characteristics and criteria among the studies, such as patient age, type of iron-chelating agents, follow-up duration, and control groups.
“Some recently published randomized trials have shown that [calcium channel blockers] may reduce the myocardial iron overload in patients with thalassemia. However, pooling these studies in a metanalysis revealed no significant difference between [calcium channel blockers] and standard iron-chelating agents in reducing myocardial iron overload, LIC, and serum ferritin,” concluded the authors.
The investigators highlighted the need for additional studies with larger sample sizes and consistent criteria to examine the potential efficacy of these calcium channel blockers in β-thalassemia.
Alali MA, Alanazi KMA, Alsayil SN, Omari Z, Shaaban A. Calcium channel blockers in conjunction with standard iron-chelating agents for β-thalassemia major: systematic literature search. Hemoglobin. 2020;44(6):446-450. doi:10.1080/03630269.2020.1853561