FLECAINIDE ACETATE TABLETS 50mg

Each tablet contains 50mg Flecainide Acetate

For excipients, see 6.1

Tablet.

White uncoated tablets.

• Treatment of AV nodal reciprocating tachycardia; arrhythmias associated with Wolff-Parkinson-White Syndrome and similar conditions with accessory pathways, when other treatment has been ineffective.

• Treatment of severe symptomatic and life-threatening paroxysmal ventricular arrhythmia which has failed to respond to other forms of therapy or where other treatments have not been tolerated.

• Treatment of paroxysmal atrial arrhythmias (atrial fibrillation, atrial flutter and atrial tachycardia) in patients with disabling symptoms after conversion provided that there is definite need for treatment on the basis of severity of clinical symptoms, when other treatment has been ineffective. Structural heart disease and/or impaired left ventricular function should be excluded because of the increased risk for pro-arrhythmic effects.

Posology

Initiation of flecainide therapy and dose changes should be made in hospital under ECG and plasma level monitoring. The clinical decision to initiate flecainide treatment should be made in consultation with a specialist. In patients with an underlying organic cardiopathy and especially those with a history of myocardial infarction, flecainide treatment should only be started when other arrhythmic agents, other than class 1C (especially amiodarone), are ineffective or not tolerated and when non-pharmacological treatment (surgery, ablation, implanted defibrillator) is not indicated. Strict medical monitoring of ECG and plasma levels during treatment is required.

Adults and adolescents (13-17 years of age):

Supraventricular arrhythmias: The recommended starting dose is 50mg twice daily and most patients will be controlled at this dose. If required the dose may be increased to a maximum of 300mg daily.

Ventricular arrhythmias: The recommended starting dose is 100mg twice daily. The maximum daily dose is 400mg and this is normally reserved for patients of large build or where rapid control of the arrhythmia is required. After 3-5 days it is recommended that the dosage be progressively adjusted to the lowest level which maintains control of the arrhythmia. It may be possible to reduce dosage during long term treatment.

Elderly patients:

In elderly patients the maximum initial daily dosage should be 100mg daily (or 50mg twice daily) as the rate of flecainide elimination from plasma may be reduced in elderly people. This should be taken into consideration when making dose adjustments.

Children:

Not recommended for children under 12 years of age.

Plasma levels:

Based on PVC suppression, it appears that plasma levels of 200-1000ng/ml may be needed to obtain the maximum therapeutic effect. Plasma levels above 700-1000ng/ml are associated with increased likelihood of adverse experiences.

Impaired renal function:

In patients with significant renal impairment (creatinine clearance of 35ml/min/1.73sq.m.or less) the maximum initial dosage should be 100mg daily (or 50mg twice daily). When used in such patients, frequent plasma level monitoring is strongly recommended. Depending on the effect and tolerability the dose may then be cautiously increased. After 6-7 days the dose may be adjusted, depending on the effect and the tolerability. Some patients with severe renal failure can have a very slow clearance of flecainide and thus a prolonged half-life (60-70 hours).

Impaired liver function:

In patients with impaired liver function, the patient should be closely monitored and the dose should not exceed 100mg daily (or 50mg twice daily).

Patients with a permanent pacemaker in situ should be treated with caution and the dose should not exceed 100mg twice daily.

In patients concurrently receiving cimetidine or amiodarone close monitoring is required. In some patients the dose may have to be reduced and should not exceed 100mg twice daily. Patients should be monitored during initial and maintenance therapy.

Plasma level monitoring and ECG control are recommended at regular intervals (ECG control once a month and long term ECG every 3 months) during therapy. During initiation therapy and when the dose is increased, an ECG should be performed every 2-4 days.

When flecainide is used in patients with dosage restrictions, frequent ECG control (additional to the regular flecainide plasma monitoring) should be made. Dose adjustment should be made at intervals of 6-8 days. In such patients an ECG should be performed in weeks 2 and 3 to control the individual dosage.

Method of Administration

For oral use. In order to avoid the possibility of food affecting the absorption of the drug, flecainide should be taken on an empty stomach or one hour before food.

Hypersensitivity to flecainide or to any of the excipients.

Flecainide is contraindicated in cardiac failure and in patients with a history of myocardial infarction who have either asymptomatic ventricular ectopics or asymptomatic non-sustained ventricular tachycardia.

It is also contraindicated in patients with long standing atrial fibrillation in whom there has been no attempt to convert to sinus rhythm; in patients with reduced or impaired ventricular function, cardiogenic shock, severe bradycardia (less than 50 bpm), severe hypotension; use in combination with disopyramide, and in patients with haemodynamically significant valvular heart disease.

Unless pacing rescue is available, flecainide should not be given to patients with sinus node dysfunction, atrial condition defects, second degree or greater atrio-ventricular block, bundle branch block or distal block.

Patients with asymptomatic or mildly symptomatic ventricular arrhythmias should not be given flecainide.

Initiation of flecainide therapy and dose changes should be made in hospital under ECG and plasma level monitoring.

Electrolyte disturbances should be corrected before using flecainide. Hypokalaemia or hyperkalaemia may influence the effects of class 1 antiarrhythmic agents. Hypokalaemia may occur in patients who use diuretics, corticosteroids or laxatives.

Since flecainide elimination from the plasma can be markedly slower in patients with significant hepatic impairment, flecainide should not be used in such patients unless the potential benefits clearly outweigh the risks. Flecainide should be used with caution in patients with impaired renal function (creatinine clearance 35ml/min/1.73sq m) and frequent therapeutic drug monitoring should be undertaken. Plasma level monitoring is strongly recommended in these circumstances.

Flecainide is known to increase endocardial pacing thresholds, ie to decrease endocardial pacing sensitivity. This effect is reversible and is more marked on the acute pacing threshold than on the chronic. Flecainide should thus be used with caution in all patients with permanent pacemakers or temporary pacing electrodes and should not be administered to patients with existing poor thresholds or non-programmable pacemakers unless suitable pacing rescue is available.

Generally, a doubling of either pulse width or voltage is sufficient to regain capture, but it may be difficult to obtain ventricular thresholds less than 1 Volt at initial implantation in the presence of flecainide.

The minor negative inotropic effect of flecainide may assume importance in patients predisposed to cardiac failure. Difficulty has been experienced in defibrillating some patients. Usually these patients were reported to have pre-existing heart disease with cardiac enlargement, a history of myocardial infarction, arterio sclerotic heart disease and cardiac failure.

Flecainide should be used with caution in patients with acute onset of atrial fibrillation following cardiac surgery.

Flecainide has been shown to increase mortality risk of post-myocardial infarction patients with asymptomatic ventricular arrhythmia.

An acceleration of the ventricular rate of atrial fibrillation in case of therapy failure has been reported.

Flecainide has a selective effect that increases the refractory period of the anterograde, and especially, the retrograde pathways. These effects are reflected in the ECG by prolongation of the QTc interval in most patients; consequently there is little effect on the JT interval. Nevertheless, there have been reports of prolongation of the JT interval of up to 4%. This action is less marked than that observed with the class 1a antiarrhythmic drugs however.

Flecainide should be used with caution in patients with sick sinus syndrome.

Flecainide is metabolized in the liver through Cytochrome P450 CYD2D6. Concomitant use of other drugs that inhibit this enzyme can lead to a reduction of flecainide elimination and consequently to a higher plasma level of flecainide. Drugs that induce Cytochrome P450 can reduce the plasma level of flecainide.

Use of flecainide with other sodium channel blockers is not recommended. Flecainide can cause the plasma digoxin level to rise by about 15%, which is unlikely to be of clinical significance for patients with plasma levels in the therapeutic range.

It is recommended that the digoxin plasma level in digitalised patients should be measured not less than 6 hours after any digoxin dose, before or after administration of flecainide.

The possibility of additive negative inotropic effects of beta-blockers and other cardiac depressants with flecainide should be recognised.

Limited data in patients receiving known enzyme inducers (phenytoin, phenobarbital, carbamazepine) indicate only a 30% increase in the rate of flecainide elimination.

Raised plasma levels and an increase in half-life of flecainide have been observed in healthy subjects receiving cimetidine (1g daily) for one week.

Use of flecainide with other class 1 anti-arrhythmics is not recommended.

When flecainide is given in the presence of amiodarone the usual dosage should be reduced and the patient monitored closely for adverse effects. Plasma level monitoring is strongly recommended in these circumstances.

Other possible drug interactions with flecainide: antidepressants (fluoxetine and tricyclics), antihistamines (astemizole and terfenadine), antimalarials (quinine and halofantrine), verapamil, quinidine and diuretics.

There are no adequate data from the use of flecainide in pregnant women.

Studies in animals have shown reproductive toxicity in one particular strain of rabbits (see section 5.3). The relevance of these findings to humans has not been established. Data have shown that flecainide crosses the placenta to the foetus in patients taking flecainide during pregnancy. Flecainide should only be used during pregnancy if clearly necessary. If flecainide is used maternal flecainide plasma levels should be monitored throughout the pregnancy.

Flecainide acetate is excreted in human breast milk and appears in concentrations which reflect those in maternal blood. Nursing mothers should not breast feed whilst taking flecainide acetate.

Driving ability and operation of machinery may be affected by side effects such as dizziness and visual disturbances.

Very common: 1/10

Common: 1/100, <1/10

Uncommon: 1/1,000, 1/100

Rare: 1/10,000, 1/1000

Very rare: 1/10,000

Not known: Cannot be estimated from the available data

• Blood and lymphatic system disorders:

Uncommon: reductions in red and white blood cells and platelets, these changes are usually mild.

• Immune system disorders:

Rare: cases of increases in anti-nuclear antibodies, with and without systemic inflammatory involvement.

• Psychiatric disorders:

Common: depression, anxiety, insomnia

Uncommon: hallucinations, confusion, amnesia,

Rare: nervousness.

• Nervous system disorders:

Very common: dizziness, and light headedness which are usually transient. Giddiness, headache.

Common: paraesthesia, ataxia, dyskinesia, hypaesthesia, syncope, tremor, vertigo, flushing, somnolence, tinnitus, increased sweating.

Uncommon: peripheral neuropathy, convulsions

• Eye disorders:

Very common: visual disturbances, such as double vision and blurring of vision these are usually transient and disappear upon continuing or reducing the dosage.

Very rare: corneal deposits.

• Cardiac disorders:

Common: pro-arrhythmic effects are most likely in patients with structural heart disease and/or significant left ventricular impairment. These pro-arrhythmic effects include the increase of the frequency of premature ventricular contractions to more severe forms of ventricular tachycardia.

Not known: specific ECG changes (prolongation of PQ, QT or QRS interval, increase in number or severity of arrhythmia), incidences of bradycardia, sinus arrest or inducement or worsening of heart failure. In patients with atrial flutter the use of flecainide has been associated with 1:1 AV conduction following initial atrial slowing with resultant ventricular acceleration.

AV block (II and III grades), bundle branch block or SA block has been reported. In these cases the therapy with flecainide should be discontinued.

• Respiratory, thoracic and mediastinal disorders:

Common: dyspnoea

Uncommon: interstitial pneumonitis

• Gastrointestinal disorders:

Common: nausea, vomiting, diarrhoea, constipation, abdominal pain

Uncommon: dysgeusia, dry mouth

• Hepatobiliary disorders:

Rare: elevated liver enzymes and jaundice.

• Skin and subcutaneous tissue disorders:

Rare: serious urticaria

Not known: photosensitivity, flushing, allergic skin reactions

• Musculoskeletal and connective tissue disorders:

Very rare: arthralgia and myalgia

• Reproductive system and breast disorders:

Very rare: impotence.

Overdose with flecainide is a potentially life threatening medical emergency. No specific antidote is known.

There is no known way of rapidly removing flecainide from the system but forced acid diuresis may theoretically be helpful. Neither dialysis nor haemoperfusion are helpful and injections of anticholinergics are not recommended. Treatment may include therapy with an inotropic agent, intravenous calcium, giving circulatory assistance (ie balloon pumping) mechanically assisting respiration or temporarily inserting a transvenous pacemaker if there are severe conduction disturbances or the patients left ventricular function is otherwise compromised.

In one case report amiodarone was administered to a patient after a flecainide overdose for therapy resistant ventricular fibrillation. However, the efficacy and safety are not proven and amiodarone is not regarded as an antidote to the flecainide overdose.

Pharmacotherapeutic group: Antiarrhythmics, class 1c, Flecainide

ATC code: CO1 BC 04

Flecainide acetate is a Class IC antiarrhythmic agent used for the treatment of severe symptomatic life-threatening ventricular arrhythmias and supraventricular arrhythmias.

Electrophysiologically, flecainide is a local anaesthetic-type (Class IC) of antiarrhythmic compound. It is an amide type of local anaesthetic, being structurally related to procainamide and encainide in so far as these agents are also benzamide derivatives.

The characterisation of flecainide as a Class IC compound is based on a triad of features: marked depression of the fast sodium channel in the heart; slow onset and offset kinetics of inhibition of the sodium channel (reflecting slow attachment to and dissociation from sodium channels); and the differential effect of the drug on the action potential duration in ventricular muscle versus Purkinje fibres, having no effect in the former and markedly shortening it in the latter. This composite of properties leads to a marked depression in conduction velocity in fibres dependant on the fast-channel fibres for depolarisation but with a modest increase in the effective refractory period when tested in isolated cardiac tissues. These electrophysiological properties of flecainide may lead to prolongation of the PR-interval and QRS duration on the ECG. At very high concentrations flecainide exerts a weak depressant effect on the slow channel in the myocardium. This is accompanied by a negative inotropic effect.

Flecainide is almost completely absorbed after oral administration and does not undergo extensive first-pass metabolism. The bioavailability from flecainide acetate tablets has been reported to be about 90%. Flecainide is extensively metabolised (subject to genetic polymorphism), the 2 major metabolites being m-O-dealkylated flecainide and m-O-dealkylated lactam of flecainide, both of which may have some activity. It is excreted mainly in the urine, approximately 30% as unchanged drug and the remainder as metabolites. About 5% is excreted in the faeces. Excretion of flecainide is decreased in renal failure, liver diseases, heart failure, and in alkaline urine. Haemodialysis removes only about 1% of unchanged flecainide.

The therapeutic plasma concentration range is generally accepted as 200 to 1000ng per ml. The elimination half-life of flecainide is about 20 hours and it is about 40% bound to plasma proteins.

Flecainide passes the placenta and is excreted in breast milk.

The only preclinical data of relevance to the prescriber which are additional to that already included in other sections of the SPC are the following effects found on reproduction. In one breed of rabbits flecainide caused teratogenicity and embryotoxicity. There were insufficient data to establish a safety margin for this effect. However, these effects were not seen in another breed of rabbits, rats and mice.

Croscarmellose sodium,

magnesium stearate,

maize starch,

pregelatinised maize starch

microcrystalline cellulose (E460).

Not applicable.

3 years.

Polypropylene containers

Do not store above 25°C.

Store in the original container.

Blister packs

Do not store above 25°C. Keep container in the outer carton.

The blister packs are manufactured from 250μm white rigid PVC/PVDC coated with 60gm^-2 PVDC and 20μm hard temper aluminium foil with 5-7g/m² PVC/PVDC compatible heat seal lacquer. The polypropylene containers are manufactured from rigid injection moulded polypropylene with snap-on polyethylene lids.

Pack sizes:

Blister: 20s, 28s, 30s, 50s, 56s, 60s, 84s, 90s, 100s, 112s, 120s, 168s, 180s.

Tablet container: 100s, 250s, 500s, 1000s.

Not all pack sizes may be marketed.

No special requirements.

Actavis UK Limited (Trading style: Actavis)

Whiddon Valley

BARNSTAPLE

N Devon EX32 8NS

PL 0142/0430

03/08/2009

03/08/2009