Table 4.
Drugs for Treatment of Isoimmune AV block a
| Drug 84 , 93 , 94 , 95 , 96 , 97 | Indication/Duration Route | F:M Drug Ratio | Efficacy Acute and Chronic | Elimination | Side Effects |
|---|---|---|---|---|---|
| Dexamethasone Fluorinated glucocorticoid |
PR on echo >170 ms or AV block onset PO |
0.5 F:M, ↓ Mab levels | 20%‐40% reversal of 2:1 block, may ↓ postnatal cardiomyopathy | Hepatic and renal | Maternal HTN, ↑ glucose, Cushing syndrome, CNS, osteoporosis, etc; transfer to breast milk |
|
IVIG Anti‐inflammatory, blocks F2/FAB receptors in placenta |
Hydrops IV |
0.5‐1.0:1 |
In HF, ↓ mortality from 80%‐25% $$$, preapproval needed |
Depends on target, mostly renal | Allergic Rxn, vaccines |
|
Hydroxychloroquine TLR blocker, ↓ endosomal pH |
Prior infant with NLE PO |
1.04:1 | ↓ heart block risk from 16% to 7% in subsequent pregnancy | Half‐life, 40‐50 days; mostly renal, some retained long‐term | ↑QTc |
|
Terbutaline Beta agonist (isoimmune and nonisoimmune AV block) |
FHR <50/min, if CHD <55/min or with hydrops PO |
1‐1.5:1 | ↑ FHR by 5‐10 beats/min, not proven to ↑ survival | Renal | ↑ maternal HR, arrhythmias, CNS |
AV, atrioventricular; CHD, congenital heart disease; CNS, central nervous system; FAB, fragment antigen‐binding; FHR, fetal heart rate; F:M, fetal:maternal; HF, hydrops fetalis; HR, heart rate; HTN, hypertension; MAb, monoclonal antibody; NLE, neonatal lupus erythematosus; Rxn, reactions; TLR, toll‐like receptor.