Improved completion rates and characterization of drug reactions with an intensive Chagas disease treatment program in rural Bolivia.
BACKGROUND
Chagas disease treatment is limited by drug availability, adverse side effect profiles of available medications, and poor adherence.


METHODS
Adult Chagas disease patients initiating 60-days of benznidazole were randomized to weekly or twice-weekly evaluations of medication adherence and screening for adverse drug events (ADEs). Mid-week evaluations employed phone-based evaluations. Adherence was measured by self-report, pill counts with intentional over-distribution, and Medication Event Monitoring Systems (MEMS). Prospective data were compared to historical controls treated with benznidazole at the same hospital.


RESULTS
162 prospective patients were compared to 172 historical patients. Pill counts correlated well with MEMS data (R = 0.498 for 7-day intervals, R = 0.872 for intervals >7 days). Treatment completion rates were higher among prospective than historical patients (82.1% vs. 65.1%), primarily due to lower abandonment rates. Rates of ADEs were lower among prospective than historical patients (56.8% vs. 66.9%). Twice-weekly evaluations increased identification of mild ADEs, prompting higher suspension rates than weekly evaluations. While twice-weekly evaluations identified ADEs earlier, they did not reduce incidence of moderate or severe ADEs. Many dermatologic ADEs were moderately severe upon presentation (35.6%), were not reduced by use of antihistamines, occurred among adult patients of all ages, and occurred throughout treatment, rather than the first few weeks alone.


CONCLUSIONS
Intensive management improved completion and identified more ADEs, but did not reduce moderate or severe ADEs. Risk of dermatologic ADEs cannot be reduced by selecting younger adults or monitoring only during the first few weeks of treatment. Pill counts and phone-based encounters are reliable tools for treatment programming in rural Bolivia.
Combined Internal Medicine/Pediatrics Residency Program, Yale School of Medicine, New Haven, Connecticut, United States of America.
Jeffrey A
JA
Tornheim
Daniel F
DF
Lozano Beltran
Robert H
RH
Gilman
Mario
M
Castellon
Marco A
MA
Solano Mercado
Walter
W
Sullca
Faustino
F
Torrico
Caryn
C
Bern
D000293:Adolescent; D000328:Adult; D000981:Antiprotozoal Agents / Q000009:adverse effects* / Q000627:therapeutic use*; D001838:Bolivia; D014355:Chagas Disease / Q000188:drug therapy*; D015331:Cohort Studies; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D009593:Nitroimidazoles / Q000009:adverse effects* / Q000627:therapeutic use*; D011446:Prospective Studies; D012424:Rural Population; D016896:Treatment Outcome; D055815:Young Adult
D000981:Antiprotozoal Agents; D009593:Nitroimidazoles; C009999:benzonidazole