RESUMEN
Topiramate (TMP) is a broad-spectrum anticonvulsant drug used to treat a wide variety of seizure disorders, for migraine prophylaxis, and for many other indications. An important side effect of TMP is metabolic acidosis, which is mediated by renal tubular defects. TMP inhibits carbonic anhydrase, an enzyme that is necessary for acid handling in the proximal renal tubule. Patients can present with asymptomatic serum electrolyte derangements, acute change in mental status, hyperventilation, cardiac arrhythmias, or other sequelae of metabolic acidosis and associated respiratory compensation. If taken chronically, TMP can cause renal stone formation, bone mineralization defects, and several other effects secondary to changes in serum and urine pH and electrolytes. There is no well-studied way to prevent metabolic acidosis in patients taking TMP, but physicians should be vigilant when prescribing this drug to patients with the history of renal diseases and other comorbidities, and aware of this potential etiology of metabolic acidosis. We present a literature review of the underlying mechanisms involved in the development of renal tubular acidosis secondary to TMP and its clinical consequences.
RESUMEN
Tuberculosis (TB) is an important cause of morbidity and mortality in the United States. Due to the unpredictable or nonspecific nature of its clinical presentations, TB can be a diagnostic challenge for physicians. In 2013, 23% of reported TB cases were culture-negative in the United States; in New York City, this was approximately 27%. The increasing number of sputum smear- and culture-negative TB patients is a serious concern because misdiagnosis and delayed treatment can lead to increased morbidity and mortality and increased infectious transmission. We report a case of a 26-year-old-female recent immigrant, who was initially managed for community-acquired pneumonia but was later found to have TB with complicated pleural effusion, despite having multiple smear- and culture-negative sputum specimens, Xpert Mycobacterium tuberculosis (MTB)/resistance to rifampin (RIF) assay (real-time polymerase chain reaction (PCR)) and pleural fluid analysis. She improved clinically on anti-tuberculosis therapy and, later, the diagnosis was confirmed by pleural biopsy.