Optimizing hepatitis C virus treatment through pharmacist interventions: Identification and management of drug-drug interactions.
OBJECTIVE
To quantify drug-drug-interactions (DDIs) encountered in patients prescribed hepatitis C virus (HCV) treatment, the interventions made, and the time spent in this process.


METHODS
As standard of care, a clinical pharmacist screened for DDIs in patients prescribed direct acting antiviral (DAA) HCV treatment between November 2013 and July 2015 at the University of Colorado Hepatology Clinic. HCV regimens prescribed included ledipasvir/sofosbuvir (LDV/SOF), paritaprevir/ritonavir/ombitasvir/dasabuvir (OBV/PTV/r + DSV), simeprevir/sofosbuvir (SIM/SOF), and sofosbuvir/ribavirin (SOF/RBV). This retrospective analysis reviewed the work completed by the clinical pharmacist in order to measure the aims identified for the study. The number and type of DDIs identified were summarized with descriptive statistics.


RESULTS
Six hundred and sixty four patients (83.4% Caucasian, 57% male, average 56.7 years old) were identified; 369 for LDV/SOF, 48 for OBV/PTV/r + DSV, 114 for SIM/SOF, and 133 for SOF/RBV. Fifty-one point five per cent of patients were cirrhotic. Overall, 5217 medications were reviewed (7.86 medications per patient) and 781 interactions identified (1.18 interactions per patient). The number of interactions were fewest for SOF/RBV (0.17 interactions per patient) and highest for OBV/PTV/r + DSV (2.48 interactions per patient). LDV/SOF and SIM/SOF had similar number of interactions (1.28 and 1.48 interactions per patient, respectively). Gastric acid modifiers and vitamin/herbal supplements commonly caused interactions with LDV/SOF. Hypertensive agents, analgesics, and psychiatric medications frequently caused interactions with OBV/PTV/r + DSV and SIM/SOF. To manage these interactions, the pharmacists most often recommended discontinuing the medication (28.9%), increasing monitoring for toxicities (24.1%), or separating administration times (18.2%). The pharmacist chart review for each patient usually took approximately 30 min, with additional time for more complex patients.


CONCLUSIONS
DDIs are common with HCV medications and management can require medication adjustments and increased monitoring. An interdisciplinary team including a clinical pharmacist can optimize patient care.
Jacob A Langness, Matthew Nguyen, Amanda Wieland, Gregory T Everson, Jennifer J Kiser, Hepatology and Transplant Clinic, University of Colorado Hospital, Aurora, CO 80045, United States.
Jacob A
JA
Langness
Jacob A Langness, Matthew Nguyen, Amanda Wieland, Gregory T Everson, Jennifer J Kiser, Hepatology and Transplant Clinic, University of Colorado Hospital, Aurora, CO 80045, United States.
Matthew
M
Nguyen
Jacob A Langness, Matthew Nguyen, Amanda Wieland, Gregory T Everson, Jennifer J Kiser, Hepatology and Transplant Clinic, University of Colorado Hospital, Aurora, CO 80045, United States.
Amanda
A
Wieland
Jacob A Langness, Matthew Nguyen, Amanda Wieland, Gregory T Everson, Jennifer J Kiser, Hepatology and Transplant Clinic, University of Colorado Hospital, Aurora, CO 80045, United States.
Gregory T
GT
Everson
Jacob A Langness, Matthew Nguyen, Amanda Wieland, Gregory T Everson, Jennifer J Kiser, Hepatology and Transplant Clinic, University of Colorado Hospital, Aurora, CO 80045, United States.
Jennifer J
JJ
Kiser
D000700:Analgesics; D000998:Antiviral Agents / Q000627:therapeutic use*; D004347:Drug Interactions; D004359:Drug Therapy, Combination; D005260:Female; D016174:Hepacivirus / Q000187:drug effects; D019698:Hepatitis C, Chronic / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010595:Pharmacists; D010604:Pharmacy / Q000379:methods; D012189:Retrospective Studies; D012254:Ribavirin / Q000008:administration & dosage; D000069616:Simeprevir / Q000008:administration & dosage; D000069474:Sofosbuvir / Q000008:administration & dosage; D016896:Treatment Outcome
D000700:Analgesics; D000998:Antiviral Agents; D012254:Ribavirin; D000069616:Simeprevir; D000069474:Sofosbuvir
Clinical pharmacist; Drug-drug interaction; Hepatitis C virus treatment