Rifampicin in Nontuberculous Mycobacterial Infections: Acute Kidney Injury with Hemoglobin Casts.

Rifampicin is a key component of multidrug regimens not only for tuberculosis, but also nontuberculous mycobacterial infections (NTM) which are on the rise worldwide. Knowledge of the toxicity profile is important. Hepatotoxicity is a well-known side effect of Rifampicin necessitating regular liver function monitoring during therapy. Acute kidney injury (AKI) is a relatively rare complication, usually resulting from allergic interstitial nephritis (AIN). Rifampicin-induced intravascular hemolysis resulting in hemoglobinuria and AKI is even more uncommon, especially in Western countries with low prevalence of mycobacterial infections. Rifampicin-induced antibodies are implicated and this complication preferentially occurs during intermittent drug treatment protocols or when Rifampicin is restarted after a long drug-free interval. Awareness of this drug complication and its unique timing is important especially among emergency room physicians where patients with AKI may first present. It is equally important for nephrologists and pathologists. We describe one such case with detailed clinical course of the patient and interesting biopsy findings of ATN with intratubular hemoglobin casts.

Lower frequency of antidepressant use in patients on renin-angiotensin-aldosterone system modifying medications.

Both hypertension and depression are common disorders which may both involve components of the hypothalamic-pituitary-adrenal axis system and the Renin-Angiotensin-Aldosterone System (RAAS). These observations, coupled with growing evidence that RAAS-active drugs may have anti-depressant properties prompted us to study the frequency of anti-depressant medication usage in the patients receiving RAAS-active agents. A chart review was performed on 378 patients who were seen during a 3-month period in a primary care clinic and who were diagnosed with hypertension. Demographic information and data on the rates of co-administration of antihypertensive and anti-depressant medications was collected. Overall, 23.7% of the sample was on an antidepressant. 20% of the patients taking a RAAS-modifying medication were on an antidepressant, compared to 34% of those not taking a RAAS-modifying medication (Χ(2) = 8.88, P = 0.003). The patients taking a beta-blocker alone had the highest rate of antidepressant usage (40%). The use of RAAS-modifying medications was associated with an even lower rate of anti-depressant usage in males compared with females. It was also observed that the patients taking an additional diuretic had a significantly lower rate of antidepressant use (17.6%, Χ(2) = 5.81, P = 0.016) compared with the patients not taking a diuretic. The patients being treated with an ACE inhibitor or ARB showed significantly lower rates of antidepressant usage. The data is supportive of the hypothesis that these agents may possess anti-depressant effects.