page113
Oral
administration of
a cardiac glycoside (such as
digoxin,
section 2.1.1)
slows the ventricular
response
in cases of atrial
fibrillation and atrial
flutter.
However,
intravenous infusion of
digoxin is rarely effective for
rapid control of ventricular rate. Cardiac glycosides are
contra-indicated in supraventricular arrhythmias asso-
ciated with accessory conducting pathways (e.g.
Wolff-
Parkinson-White syndrome).
Verapamil (section 2.6.2) is usually effective for supra-
ventricular
tachycardias.
An initial
intravenous
dose
(important:
serious
beta-blocker
interaction hazard,
see p.
133)
may be followed by oral
treatment;
hypo-
tension may occur with large doses.
It
should not
be
used for tachyarrhythmias where the QRS complex is
wide (i.e.
broad complex)
unless
a supraventricular
origin has been established beyond reasonable doubt.
It
is also contra-indicated in atrial
fibrillation or atrial
flutter associated with accessory conducting pathways
(e.g. Wolff-Parkinson-White syndrome). It should not be
used in children with arrhythmias without
specialist
advice; some supraventricular arrhythmias in childhood
can be accelerated by verapamil
with dangerous con-
sequences.
Intravenous administration of
a beta-blocker (section
2.4) such as esmolol
or propranolol,
can achieve rapid
control of the ventricular rate.
Drugs for both supraventricular and ventricular arrhy-
thmias include amiodarone,
beta-blockers (see p.
98),
disopyramide,
flecainide,
procainamide
(available
from ‘special-order’ manufacturers or specialist import-
ing companies, see p.
988), and propafenone, see below
under Supraventricular and Ventricular Arrhythmias.
ADENOSINE
Indications
rapid reversion to sinus rhythm of parox-
ysmal supraventricular tachycardias,
including those
associated with accessory conducting pathways (e.g.
Wolff-Parkinson-White syndrome); aid to diagnosis of
broad or narrow complex supraventricular tachy-
cardias
Cautions
monitor ECG and have resuscitation facil-
ities available;
atrial fibrillation or flutter with acces-
sory pathway (conduction down anomalous pathway
may increase); first-degree AV block;
bundle branch
block; left main coronary artery stenosis; uncorrected
hypovolaemia;
stenotic valvular heart disease;
left to
right shunt;
pericarditis; pericardial effusion; auto-
nomic dysfunction;
stenotic carotid artery disease
with cerebrovascular insufficiency; recent myocardial
infarction;
heart failure;
heart transplant (see below);
interactions: Appendix 1 (adenosine)
Contra-indications
second- or third-degree AV block
and sick sinus syndrome (unless pacemaker fitted);
long QT syndrome;
severe hypotension;
decompen-
sated heart failure;
chronic obstructive lung disease
(including asthma)
Pregnancy
large doses may produce foetal toxicity;
manufacturer advises use only if essential
Breast-feeding
no information available—unlikely to
be present in milk owing to short half-life
Side-effects
nausea;
arrhythmia (discontinue if asys-
tole or severe bradycardia occur),
sinus pause,
AV
block,
flushing,
angina (discontinue), dizziness;
dys-
pnoea;
headache;
less commonly
metallic taste;
pal-
pitation,
hyperventilation, weakness,
blurred vision,
sweating;
very rarely
transient worsening of intracra-
nial hypertension,
bronchospasm,
injection-site reac-
tions;
also reported
vomiting,
syncope,
hypotension
(discontinue if severe),
cardiac arrest,
respiratory
failure (discontinue),
and convulsions
Dose
. By rapid intravenous injection into central or large
peripheral vein,
6 mg over 2 seconds with cardiac
monitoring;
if necessary followed by 12 mg after 1–2
minutes,
and then by 12 mg after a further 1–2 min-
utes;
increments should not be given if high level AV
block develops at any particular dose
Important
Patients with a heart transplant are very sensi-
tive to effects of adenosine and should receive initial dose of
3 mg over 2 seconds, followed if necessary by 6 mg after 1–2
minutes,
and then by 12 mg after a further 1–2 minutes.
Also, if essential to give with dipyridamole reduce adenosine
dose to a quarter of the usual dose
Note
Adenosine doses in the BNF may differ from those in
product literature
Adenocor
c
(Sanofi-Aventis) A
Injection
, adenosine 3 mg/mL in physiological saline,
net price 2-mL vial = £4.45 (hosp.
only)
Note
Intravenous infusion of
adenosine (
Adenoscan
c
,
Sanofi-
Aventis) may be used in conjunction with radionuclide myocardial
perfusion imaging in patients who cannot exercise adequately or
for whom exercise is inappropriate—consult product literature
DRONEDARONE
Indications
see notes above
Cautions
heart failure (avoid in patients with a recent
history of moderate heart failure,
or with a signifi-
cantly reduced left ventricular function);
correct
hypokalaemia and hypomagnesaemia before starting
and during treatment;
measure serum creatinine 7
days after initiation;
interactions: Appendix 1 (dro-
nedarone)
Contra-indications
second- or third-degree AV block
and sick sinus syndrome (unless pacemaker fitted);
bradycardia;
prolonged QT interval; haemodynami-
cally unstable patients (including those with moderate
or severe heart failure)
Hepatic impairment
avoid in severe impairment
Renal impairment
avoid if eGFR less than 30 mL/
minute/1.73 m
2
Pregnancy
manufacturer advises avoid—toxicity in
animal
studies
Breast-feeding
manufacturer advises avoid—present
in milk in
animal
studies
Side-effects
gastro-intestinal disturbances;
QT-inter-
val prolongation,
bradycardia;
fatigue,
asthenia;
rash,
pruritus; raised serum creatinine;
less commonly
taste
disturbance;
erythema,
eczema, dermatitis,
photo-
sensitivity
Dose
. By mouth,
400 mg twice daily
Multaq
c
(Sanofi-Aventis) T A
Tablets
,
f/c,
dronedarone (as hydrochloride) 400 mg,
net price 20-tab pack = £22.50, 60-tab pack = £67.50.
Label:
21
Supraventricular and ventricular
arrhythmias
Amiodarone is used in the treatment
of
arrhythmias,
particularly when other drugs are ineffective or contra-
indicated. It can be used for paroxysmal supraventricu-
BNF 61
2.3.2 Drugs for arrhythmias
93
2
Cardiovascular system