The Effect of Doxorubicin and Allopurinol in Chemomyectomy

ABSTRACT

This study was designed to identify doxorubicin as a permanent chemomyectomy agent that overcomes reversible effect of botulinum toxin A. Doxorubicin was assessed for its ability to bring about a permanent chemomyectomy and the effects of pretreatment were observed to assess its ability to prevent any complications brought about by doxorubicin. A total of thirteen rabbits were assigned to the control group(n=3) and two experimental groups(n=5 for each group). To investigate the myopathic changes following the injections of the agent, both orbicularis oculi muscles of the lower eyelids of each rabbit in the control group were directly injected with single dose of 0.2ml normal saline. Group I were injected with 0.5mg/0.2ml of doxorubicin into the right eyelid and 1.0 mg/0.2 ml of doxorubicin into the left. Group II were given an intravenous injection of 35mg/kg of allopurinol as the pretreatment, then 30minutes later injected with 0.5mg/0.2ml of doxorubicin into the right and 1.0mg/ 0.2ml of doxorubicin into the left. The rabbits were examined daily to monitor the onset, duration and size of skin necrosis and histologically examined two and four months after initial injections. The myopathic change after doxorubicin injection was persistent and irreversible. The dose related effects of doxorubicin chemomyectomy were confirmed by the histologic finding. Skin necrosis occurred in all cases of doxorubicin injection(both 0.5mg and 1.0mg), however the allopurinol pretreatment decreased the size of the skin necrosis in case of the high dose(1.0mg) of doxorubicin. The combined use of allopurinol and doxorubicin reduced the myopathic change more effectively than doxorubicin use alone. Further study is needed to determine optimal dose and administration method, which we feel will contribute to safer and permanent chemomyectomy.