Perioral numbness associated with intravenous pentamidine administration

To report a case of perioral numbness associated with intravenous pentamidine.

A 56-year-old female with acute myelogenous leukemia in remission developed Pneumocystis carinii infection. Treatment was initiated with trimethoprim/sulfamethoxazole (TMP/SMX), but the patient subsequently developed a rash on day 10 of treatment. TMP/SMX was discontinued and intravenous pentamidine was started in order to complete a 21 day treatment course for P. carinii pneumonia (PCP). However, on day 3 of pentamidine treatment, the patient reported perioral numbness during the infusion. The numbness disappeared soon after completion of the infusion but recurred with all subsequent pentamidine infusions.

Paresthesias in general and facial area numbness in particular have been reported with pentamidine administration. While it is possible such adverse events may be a result of pentamidine's effect on serum electrolytes and glucose, especially hypocalcemia and hypoglycemia, these laboratory values were not grossly affected by pentamidine in our patient. The Naranjo probability scale revealed a probable adverse reaction of perioral numbness associated with intravenous pentamidine.

Pentamidine is considered an alternative agent to TMP/SMX in the treatment of PCP. Although they do not commonly occur, paresthesias have been reported with pentamidine therapy. Healthcare practitioners should be aware of this type of event in association with pentamidine administration, especially as it may not be associated with overt serum glucose or electrolyte disturbances.