[Digitalis intoxication secondary to treatment with clarithromycin].
OBJECTIVE
The goal of this study was to investigate the percentage of patients concurrently receiving digoxin and clarithromycin who exhibited serum digoxin concentrations above the therapeutic range because of a likely interaction between both drugs, and whether digitalis intoxication ensued.


METHODS
A descriptive, retrospective study carried out from January 2002 to December 2003 in all inpatients concurrently receiving digoxin and clarithromycin whose serum digoxin concentrations were monitored by the Pharmacy Department s Pharmacokinetics Section.


RESULTS
Twenty-six patients having received digoxin and clarithromycin concurrently during their hospital stay were included in the study. Of these, 12 patients (46.2%) had serum digoxin concentrations above the therapeutic range: 7 received digoxin in doses unsuited for their age and/or renal function, and 2 fell short of the mean period of time considered adequate for an interaction to occur. Therefore, only 3 patients had serum digoxin concentrations above the therapeutic range, probably because of an interaction with clarithromycin, and all three had digitalis intoxication symptoms.


CONCLUSIONS
According to the results of our study, 11.5% of patients concurrently receiving digoxin and clarithromycin had serum digoxin concentrations above the therapeutic range because of a likely interaction between these two drugs, with digitalis intoxication ensuing. Thus, we deem it necessary to monitor serum digoxin concentrations in patients receiving clarithtomycin.
Bonilla Porras
M
M
Servicio de Farmacia, Hospital Severo Ochoa, Leganés, Madrid, Spain. macabonilla@hotmail.com
Lucena Campillo
M A
MA
Delgado Silveira
E
E
Ramallal Jiménez Del Llano
M C
MC
García Díaz
B
B
D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000009:adverse effects*; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000506:poisoning*; D017291:Clarithromycin / Q000008:administration & dosage / Q000009:adverse effects*; D004071:Digitalis Glycosides / Q000008:administration & dosage / Q000506:poisoning*; D004347:Drug Interactions; D005260:Female; D006801:Humans; D008297:Male; D012189:Retrospective Studies
D000900:Anti-Bacterial Agents; D002316:Cardiotonic Agents; D004071:Digitalis Glycosides; D017291:Clarithromycin