The Food and Drug Administration (FDA) has approved tafamidis meglumine (Vyndaqel) and tafamidis (Vyndamax) capsules for the treatment of cardiomyopathy caused by transthyretin-mediated amyloidosis in adults. These are the first FDA-approved drug treatments for this rare genetic disorder. The goal of therapy is to reduce cardiovascular-related hospitalization and cardiovascular deaths.

Transthyretin amyloidosis results from the slow buildup of abnormal deposits of the protein amyloid. Patients with the cardiac form of transthyretin amyloidosis develop cardiomyopathy with arrythmias, cardiomegaly, and orthostatic hypotension, leading to progressive heart failure and death.

Although Vyndamax and Vyndaqel have an identical active component, Vyndaqel has a longer, more complex chemical composition and the molecular weights of these drugs are also different. They are also not identical in their recommended dosage and cannot be substituted for each other on a milligram per milligram basis. They do, however, share a common medication label. (In this item, tafamidis refers to both products.)

The efficacy of tafamidis was evaluated in a randomized, double-blind, placebo-controlled study of 441 patients with two variants of cardiomyopathy caused by transthyretin-mediated amyloidosis (wild type and hereditary). The patients received one of the two forms of tafamidis or placebo. Those receiving a tafamidis preparation lived longer and were hospitalized less often than those receiving placebo. Because the number of withdrawals for suspected adverse effects was similar in both the study and placebo groups, no adverse effects specific to tafamidis were identified. It is possible that adverse effects may become apparent with wider use. Nurses should encourage patients prescribed tafamidis to report any adverse effects to the FDA at (800) FDA-1088.

For complete prescribing information for Vyndaqel and Vyndamax, see http://www.accessdata.fda.gov/drugsatfda_docs/label/2019/211996s000,212161s000lbl.pdf.