95
Elimination
Half-Life
Mechanism of
Action
Major Adverse
Effects
Important Pharmacokinetic
Drug Interactions
14–59 d Inhibits I
Kr
, I
Ks
,
I
Na
, I
Kur
, I
to
, I
Ca-L
,
I
KAch
Noncompetitive
betablocker
AV block
Bradycardia
Corneal
microdeposits
Elevation in
transaminases
Hepatotoxicity
Hyperthyroidism
Hypothyroidism
Nausea
QT prolongation
Peripheral
neuropathy
Photosensitivity
Pulmonary
fibrosis
Skin pigmentation
(blue-grey)
TdP
Moderate* inhibitor of CYP
2C9, weak
†
inhibitor of CYP
2D6
Some inhibition of CYP3A
Increases plasma
concentrations of warfarin,
lovastatin,
‡
simvastatin,
§
cyclosporine
Inhibits p-gp
Increases plasma
concentrations of digoxin
10 h Inhibits I
Kr
and
augments late I
Na
QT prolongation
TdP
Dofetilide is renally excreted
via the renal cation transport
system. e following drugs
inhibit renal cation transport,
increase plasma dofetilide
concentrations, and are
contraindicated in patients
taking dofetilide:
Cimetidine
Dolutegravir
Ketoconazole
Megestrol
Prochlorperazine
Trimethoprim (alone
or in combination with
sulfamethoxazole)
Verapamil
In addition,
hydrochlorothiazide (alone
or in combination with
triamterene) increases plasma
dofetilide concentrations and
should not be coadministered
with dofetilide
