gms | German Medical Science

Objective: A 47-year-old man presented with a history of chronic neuropathic pain treated with intrathecal application of morphine for many years. In spite of a remarkable dose escalation no noteworthy pain relief had been achieved. Ziconotide had been tested without pain relief but with severe side effects in this patient.

Methods: A combination of morphine and clonidine was delivered by a programmable pump, slowly increasing the clonidine rate over several weeks. For ease of transition and minimization of hospitalization, which was a special concern of this patient, combining clonidine and morphine was chosen over monotherapy with hydromorphone, with both possibilities being described as equal alternatives in literature.

Results: Considerable pain relief was achieved, decreasing the VAS score from 10 to 4. However, after developing erectile dysfunction and hypotension, the patient decided not to continue with the combined application of morphine and clonidine, switching back to the former monotherapy with morphine. Thereafter, erectile dysfunction disappeared, and blood pressure returned to normal levels.

Conclusions: The occurrence of erectile dysfunction and hypotension in connection with intrathecal application of clonidine has not yet been described in literature. In this patient, these rare side effects decisively impaired life quality, subjectively outweighing the considerable pain relief which could be achieved after formerly inefficacious treatment. Further investigation might be needed to estimate the connection of erectile dysfunction and hypotension to intrathecal application of clonidine.