encainide (Enkaid)

Pharmacokinetics

• metabolized by liver to 2 major metabolites
  • O-demethylencaide (ODE)
    • therapeutic level: 100-300 ng/mL
  • 3-methoxy-O-demethylencaide (MODE)
    • therapeutic level: 60-280 ng/mL
• t1/2 1.2-3.4 hours
• 7-9% of population are poor metabolizers
  • t1/2 increases to 9 hours

elimination via liver

1/2life = 1.2-3.4 hours

protein binding = 70-78 %

Adverse effects

• hypotension
• bradycardia
• seizures
• chest pain
• ventricular arrhythmias

• drug adverse effects of antiarrhythmic agent, Group IC

Drug interactions

• cimetidine may increase encainide levels

• drug interaction(s) of antiarrhythmic agents in combination with diuretics

Laboratory

• specimen: serum, plasma (EDTA, heparin)
• methods: RIA, HPLC
• interferences: up to 18% cross-reactivity with N-demethyl metabolite with RIA

Mechanism of action

Class Ic antiarrhythmic agent

More general terms

• antiarrhythmic agent, Group IC

Database

• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=48033
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=48041
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=4630918
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=48040