Jr. Fischer et Rk. Baer, ACUTE MYOPATHY ASSOCIATED WITH COMBINED USE OF CORTICOSTEROIDS AND NEUROMUSCULAR BLOCKING-AGENTS, The Annals of pharmacotherapy, 30(12), 1996, pp. 1437-1445
OBJECTIVE: TO review the occurrence and pathophysiology of myopathy as
sociated with combined use of neuromuscular blocking agents (NMBAs) an
d systemic corticosteroids. DATA SOURCES: A MEDLINE search (1985 to Ju
ly 1995, English language) yielded case reports and clinical studies i
nvolving myopathy or weakness associated with the use of NMBAs and/or
corticosteroids. References cited in those articles were reviewed. DAT
A SYNTHESIS: Prolonged muscle weakness has been reported in intubated
patients in the intensive care unit (ICU) who were receiving NMBAs and
/or corticosteroids. Many cases involved the use of both agents in ind
ividuals with no underlying risk factors. The term ''blocking agent-co
rticosteroid myopathy'' (BACM) has been used to describe this myopathy
when it develops following combined use of these agents. Features com
mon to BACM include prolonged weakness, elevated creatine kinase conce
ntrations, myopathic features on electromyography, normal nerve conduc
tion and sensation, and reduced deep tendon reflexes. Muscle biopsy re
sults vary, but tend to show type 1 and/or 2 fiber atrophy without inf
lammation. Some recently reported cases revealed thick myosin myofilam
ent loss, which is consistent with findings in denervated rat muscle a
fter exposure to corticosteroids. Two small prospective studies report
ed that 36-50% of mechanically ventilated patients receiving either on
e or both drugs developed prolonged weakness. CONCLUSIONS: NMBAS and c
orticosteroids alone have both been reported to cause myopathy in pati
ents in the ICU. When coadministered, these agents appear to confer an
even greater risk of myopathy; the exact pathology is not understood.
Concomitant use of NMBAs and corticosteroids should be avoided if pos
sible. Guidelines for cautious use and careful monitoring are suggeste
d when combined use is deemed necessary.