P. Sjogren et al., DISAPPEARANCE OF MORPHINE-INDUCED HYPERALGESIA AFTER DISCONTINUING ORSUBSTITUTING MORPHINE WITH OTHER OPIOID AGONISTS, Pain, 59(2), 1994, pp. 313-316
Hyperalgesia and allodynia in 4 cancer patients treated with morphine
disappeared after discontinuing or substituting morphine with other op
ioid agonists. The first case describes a young female who developed h
yperalgesia and myoclonus during intravenous morphine infusion. The hy
peralgesia and myoclonus disappeared when the morphine administration
was discontinued and she felt comfortable on small and sporadic oral d
oses of methadone. The second case describes hyperalgesia occurring af
ter a small dose of sustained-release morphine which disappeared after
alternative use of oral ketobemidone. The third case describes hypera
lgesia following high doses of intramuscular morphine which disappeare
d after alternative use of continuous subcutaneous infusion of sufenta
nil. The fourth case describes a boy developing hyperalgesia after hig
h doses of oral and intramuscular morphine. The hyperalgesia disappear
ed after discontinuing morphine administration but withdrawal symptoms
developed due to too small doses of methadone. Possible mechanisms of
morphine-induced hyperalgesia are discussed.