antibioticsbooks

274 PART 6 Antiparasitic Drugs
QT prolongation with ventricular arrhythmia
have also been reported.
Metabolic: Pentamidine is toxic to the pancreas,
leading to dysglycemias in up to 25% of patients.
The course of this toxicity may initially manifest
as hypoglycemia because pentamidineinduced
pancreatic injury causes release of
insulin from islet cells. Later, continuing injury
can cause a decrease in pancreatic function,
with hypoinsulinemia and hyperglycemia.
Continued use may lead to irreversible damage,
leaving patients with diabetes mellitus.
Other manifestations of pancreatitis may also
occur.
Renal: Nephrotoxicity is common with pentamidine,
although it is generally reversible upon
drug discontinuation. Electrolyte disturbances,
including hypokalemia and hypocalcemia, may
also occur.
Respiratory: Administration of pentamidine as
an inhalation may induce bronchoconstriction,
especially in patients with asthma.
Pretreatment with an inhaled bronchodilator
may attenuate these effects.
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Important Facts
• In clinical trials of pentamidine as treatment
for Pneumocystis pneumonia, pentamidine
appears to be equal in efficacy to TMP/SMX;
however, only about half of patients could
tolerate a full course of IV pentamidine without
discontinuing the drug or decreasing the
dose. Careful monitoring (ECG, metabolic
panel) and supportive care interventions
(electrolyte replacement, glucose, or insulin