page115
pulmonary toxicity (including pneumonitis and fibro-
sis);
tremor,
sleep disorders;
hypothyroidism, hyper-
thyroidism;
reversible corneal microdeposits (some-
times with night glare); phototoxicity, persistent slate-
grey skin discoloration (see also notes above), injec-
tion-site reactions;
less commonly
onset or worsening
of arrhythmia,
conduction disturbances (see Cau-
tions),
peripheral neuropathy and myopathy (usually
reversible on withdrawal);
very rarely
chronic liver
disease including cirrhosis,
sinus arrest,
broncho-
spasm (in patients with severe respiratory failure),
ataxia,
benign intracranial hypertension,
headache,
vertigo, epididymo-orchitis, impotence, haemolytic or
aplastic anaemia,
thrombocytopenia,
rash (including
exfoliative dermatitis),
hypersensitivity including
vasculitis,
alopecia,
impaired vision due to optic
neuritis or optic neuropathy (including blindness),
anaphylaxis on rapid injection,
also hypotension,
respiratory distress syndrome,
sweating,
and hot
flushes
Dose
. By mouth, 200 mg 3 times daily for 1 week reduced to
200 mg twice daily for a further week; maintenance,
usually 200 mg daily or the minimum required to
control the arrhythmia
.
By intravenous infusion (see Cautions above), initially
5 mg/kg over 20–120 minutes with ECG monitoring;
subsequent infusion given if necessary according to
response up to max.
1.2 g in 24 hours
. Ventricular fibrillation or pulseless ventricular tachy-
cardia refractory to defibrillation,
section 2.7.3
Amiodarone
(Non-proprietary) A
Tablets
,
amiodarone hydrochloride 100 mg,
net price
28-tab pack = £1.75;
200 mg,
28-tab pack = £2.22.
Label:
11
Injection
,
amiodarone hydrochloride 30 mg/mL,
net
price 10-mL prefilled syringe = £19.60
Excipients
may include benzyl alcohol (avoid in neonates unless no
safer alternative available,
see Excipients,
p.
2)
Sterile concentrate
,
amiodarone hydrochloride
50 mg/mL, net price 3-mL amp = £1.33, 6-mL amp =
£2.86.
For dilution and use as an infusion
Excipients
may include benzyl alcohol (avoid in neonates unless no
safer alternative available,
see Excipients,
p.
2)
Cordarone X
c
(Sanofi-Aventis) A
Tablets
,
scored,
amiodarone hydrochloride 100 mg,
net price 28-tab pack = £4.28; 200 mg, 28-tab pack =
£6.99.
Label:
11
Sterile concentrate
,
amiodarone hydrochloride
50 mg/mL,
net price 3-mL amp = £1.33.
For dilution
and use as an infusion
Excipients
include benzyl alcohol (avoid in neonates unless no safer
alternative available,
see Excipients, p.
2)
DISOPYRAMIDE
Indications
ventricular arrhythmias,
especially after
myocardial infarction;
supraventricular arrhythmias
Cautions
monitor for hypotension,
hypoglycaemia,
ventricular tachycardia, ventricular fibrillation or tor-
sade de pointes (discontinue if occur); atrial flutter or
atrial tachycardia with partial block,
bundle branch
block,
heart failure (avoid if severe);
prostatic enlar-
gement;
susceptibility to angle-closure glaucoma;
avoid in acute porphyria (section 9.8.2); interactions:
Appendix 1 (disopyramide)
Contra-indications
second- and third-degree heart
block and sinus node dysfunction (unless pacemaker
fitted);
cardiogenic shock;
severe uncompensated
heart failure
Hepatic impairment
half-life prolonged—may need
dose reduction
Renal impairment
reduce dose by increasing dose
interval; adjust according to response;
avoid sus-
tained-release preparation
Pregnancy
may induce labour if used in third trimester
Breast-feeding
present in milk—use only if essential
and monitor infant for antimuscarinic effects
Side-effects
ventricular tachycardia, ventricular
fibrillation or torsade de pointes (usually associated
with prolongation of QRS complex or QT interval—
see Cautions above), myocardial depression,
hypo-
tension,
AV block;
antimuscarinic effects include dry
mouth,
blurred vision,
urinary retention,
and very
rarely angle-closure glaucoma;
gastro-intestinal irri-
tation; psychosis, cholestatic jaundice, hypoglycaemia
also reported (see Cautions above)
Dose
. By mouth,
300–800 mg daily in divided doses
. By slow intravenous injection, 2 mg/kg over at least 5
minutes to a max.
of 150 mg,
with ECG monitoring,
followed immediately
either
by 200 mg by mouth,
then 200 mg every 8 hours for 24 hours
or
400 micrograms/kg/hour by intravenous infusion;
max.
300 mg in first hour and 800 mg daily
Disopyramide
(Non-proprietary) A
Capsules
,
disopyramide (as phosphate) 100 mg,
net
price 84 = £24.38;
150 mg,
84 = £32.57
Rythmodan
c
(Sanofi-Aventis) A
Capsules
,
disopyramide 100 mg (green/beige),
net
price 84-cap pack = £14.14;
150 mg,
84-cap pack =
£18.76
Injection
,
disopyramide (as phosphate) 10 mg/mL,
net price 5-mL amp = £2.61
Modified release
Rythmodan Retard
c
(Sanofi-Aventis) A
Tablets
,
m/r,
scored,
f/c,
disopyramide (as phos-
phate) 250 mg,
net price 60-tab pack = £27.72.
Label:
25
Dose
250–375 mg every 12 hours
FLECAINIDE ACETATE
Indications
capsules, tablets, and injection:
AV nodal
reciprocating tachycardia,
arrhythmias associated
with accessory conducting pathways (e.g.
Wolff-Par-
kinson-White syndrome), disabling symptoms of par-
oxysmal atrial fibrillation in patients without left
ventricular dysfunction (arrhythmias of recent onset
will respond more readily)
Immediate-release tablets only:
symptomatic sus-
tained ventricular tachycardia, disabling symptoms of
premature ventricular contractions or non-sustained
ventricular tachycardia in patients resistant to or
intolerant of other therapy
Injection only:
ventricular tachyarrhythmias resistant
to other treatment
Cautions
patients with pacemakers (especially those
who may be pacemaker dependent because stimula-
tion threshold may rise appreciably); atrial fibrillation
following heart surgery;
elderly (accumulation may
occur);
ECG monitoring and resuscitation facilities
BNF 61
2.3.2 Drugs for arrhythmias
95
2
Cardiovascular system