ACCOLATE™

'Accolate' contains 20 mg zafirlukast in each tablet.

For excipients, see 6.1.

Film-coated tablet.

White to off white, round, biconvex film coated tablet.

'Accolate' is indicated for the treatment of asthma.

'Accolate' should be taken continuously.

Adults and children aged 12 years and over:

The dosage is one 20 mg tablet twice daily. This dosage should not be exceeded. Higher doses may be associated with elevations of one or more liver enzymes consistent with hepatotoxicity.

As food may reduce the bioavailability of zafirlukast, 'Accolate' should not be taken with meals.

Elderly:

The clearance of zafirlukast is significantly reduced in elderly patients (over 65 years old), and C_max and AUC are approximately double those of younger adults. However, accumulation of zafirlukast is no greater than that seen in multiple-dose trials conducted in adult subjects with asthma, and the consequences of the altered kinetics in the elderly are unknown.

Clinical experience with 'Accolate' in the elderly (over 65 years) is limited and caution is recommended until further information is available.

Children:

There is no clinical experience of the use of 'Accolate' in children under 12 years of age.

Until safety information is available, the use of 'Accolate' in children is contraindicated.

Renal impairment:

No dosage adjustment is necessary in patients with mild renal impairment. However, experience is limited in patients with moderate to severe renal impairment (see section 5.2) so clear dose recommendations cannot be given; 'Accolate' should be used with caution in this patient group.

'Accolate' should not be given to patients who have previously experienced hypersensitivity to the product or any of its ingredients.

'Accolate' is contraindicated in patients with hepatic impairment or cirrhosis; it has not been studied in patients with hepatitis or in long term studies of patients with cirrhosis.

'Accolate' is contraindicated in children under 12 years of age until safety information is available.

'Accolate' should be taken regularly to achieve benefit, even during symptom free periods. 'Accolate' therapy should normally be continued during acute exacerbations of asthma.

'Accolate' does not allow a reduction in existing steroid treatment.

As with inhaled steroids and cromones (disodium cromoglycate, nedocromil sodium), 'Accolate' is not indicated for use in the reversal of bronchospasm in acute asthma attacks.

'Accolate' has not been evaluated in the treatment of labile (brittle) or unstable asthma.

Cases of eosinophilic conditions, including Churg-Strauss Syndrome and eosinophilic pneumonia have been reported in association with Accolate usage. Presentations may involve various body systems including vasculitic rash, worsening pulmonary symptoms, cardiac complications or neuropathy. A causal relationship has neither been confirmed nor refuted. If a patient develops an eosinophilic condition, or a Churg-Strauss Syndrome type illness, Accolate should be stopped. A rechallenge test should not be performed and treatment should not be restarted.

Elevations in serum transaminases can occur during treatment with 'Accolate'. These are usually asymptomatic and transient but could represent early evidence of hepatotoxicity, and have very rarely been associated with more severe hepatocellular injury, fulminant hepatitis and liver failure, some of which resulted in a fatal outcome.. Extremely rarely, cases of fulminant hepatitis and liver failure have been reported in patients in whom no previous clinical signs or symptoms suggestive of liver dysfunction were reported.

If clinical symptoms or signs suggestive of liver dysfunction occur (e.g. anorexia, nausea, vomiting, right upper quadrant pain, fatigue, lethargy, flu-like symptoms, enlarged liver, pruritus and jaundice), Accolate should be discontinued. The serum transaminases, in particular serum ALT, should be measured immediately and the patient managed accordingly.

Physicians may consider the value of routine liver function testing. Periodic serum transaminase testing has not proven to prevent serious injury but is generally believed that early detection of drug-induced hepatic injury along with immediate withdrawal of the suspect drug may enhance the likelihood of recovery. If liver function testing shows evidence of hepatotoxicity 'Accolate' should be discontinued immediately and the patient managed accordingly.

Patients in whom 'Accolate' was withdrawn because of hepatotoxicity should not be re-exposed to 'Accolate'.

'Accolate' may be administered with other therapies routinely used in the management of asthma and allergy. Inhaled steroids, inhaled and oral bronchodilator therapy, antibiotics and antihistamines are examples of agents which have been co-administered with 'Accolate' without adverse interaction.

'Accolate' may be administered with oral contraceptives without adverse interaction.

Co-administration with warfarin results in an increase in maximum prothrombin time by approximately 35%. It is therefore recommended that if 'Accolate' is co-administered with warfarin, prothrombin time should be closely monitored. The interaction is probably due to an inhibition by zafirlukast of the cytochrome P450 2C9 isoenzyme system.

In clinical trials co-administration with theophylline resulted in decreased plasma levels of zafirlukast, by approximately 30%, but with no effect on plasma theophylline levels. However, during post-marketing surveillance, there have been rare cases of patients experiencing increased theophylline levels when co-administered 'Accolate'.

Co-administration with terfenadine resulted in a 54% decrease in AUC for zafirlukast, but with no effect on plasma terfenadine levels.

Co-administration with acetylsalicylic acid ("aspirin", 650 mg four times a day) may result in increased plasma levels of zafirlukast, by approximately 45%.

Co-administration with erythromycin will result in decreased plasma levels of zafirlukast, by approximately 40%.

The clearance of zafirlukast in smokers may be increased by approximately 20%.

At concentrations of 10 microgram/ml and above, zafirlukast causes increases in the assay value for bilirubin in animal plasma. However, zafirlukast has not been shown to interfere with the 2,5-dichlorophenyl diazonium salt method of bilirubin analysis of human plasma.

The safety of 'Accolate' in human pregnancy has not been established. In animal studies, zafirlukast did not have any apparent effect on fertility and did not appear to have any teratogenic or selective toxic effect on the foetus. The potential risks should be weighed against the benefits of continuing therapy during pregnancy and 'Accolate' should be used during pregnancy only if clearly needed.

Zafirlukast is excreted in human breast milk. 'Accolate' should not be administered to mothers who are breast-feeding.

There is no evidence that 'Accolate' affects the ability to drive and use machinery.

The following have been reported in association with the administration of 'Accolate':

The above events have usually resolved following cessation of therapy. Headache and gastrointestinal disturbance are usually mild and do not necessitate withdrawal from therapy.

In placebo-controlled clinical trials, an increased incidence of infection has been observed in elderly patients given 'Accolate' (7.8% vs 1.4%). Infections were usually mild, predominantly affecting the respiratory tract.

Limited information exists with regard to the effects of overdosage of 'Accolate' in humans.

Management should be supportive. Removal of excess medication by gastric lavage may be helpful.

ATC Code: R03D C01.

Pharmacotherapeutic Group: Leukotriene receptor antagonists.

The cysteinyl leukotrienes (LTC₄, LTD₄ and LTE₄) are potent inflammatory eicosanoids released from various cells including mast cells and eosinophils. These important pro-asthmatic mediators bind to cysteinyl leukotriene receptors found in the human airway. Leukotriene production and receptor occupation has been implicated in the pathophysiology of asthma. Effects include smooth muscle contraction, airway oedema and altered cell activity associated with the inflammatory process, including eosinophil influx to the lung.

'Accolate' is a competitive highly selective and potent oral peptide leukotriene antagonist of LTC₄, LTD₄ and LTE₄ components of slow reacting substance of anaphylaxis. In vitro studies have shown that 'Accolate' antagonises the contractile activity of all three peptide leukotrienes (leukotriene C₄, D₄, and E₄) in human conducting airway smooth muscle to the same extent. Animal studies have shown 'Accolate' to be effective in preventing peptide leukotriene-induced increases in vascular permeability, which give rise to oedema in the airways, and to inhibit peptide leukotriene-induced influx of eosinophils into airways.

The specificity of 'Accolate' has been shown by its action on leukotriene receptors and not prostaglandin, thromboxane, cholinergic and histamine receptors.

In a placebo-controlled study where segmental bronchoprovocation with allergen was followed by bronchoalveolar lavage 48 hours later, zafirlukast decreased the rise in basophils, lymphocytes and histamine, and reduced the stimulated production of superoxide by alveolar macrophages.

'Accolate' attenuated the increase in bronchial hyperresponsiveness that follows inhaled allergen challenge. Further, methacholine sensitivity was diminished by long-term dosing with 'Accolate' 20 mg twice daily.

Further, in clinical trials evaluating chronic therapy with 'Accolate', the lung function measured when plasma levels were at trough showed sustained improvements over baseline.

'Accolate' shows a dose dependent inhibition of bronchoconstriction induced by inhaled LTD₄. Asthmatic patients are approximately 10-fold more sensitive to the bronchoconstricting activity of inhaled LTD₄. A single oral dose of 'Accolate' can enable an asthmatic patient to inhale 100 times more LTD₄ and shows significant protection at 12 and 24 hours.

'Accolate' inhibits the bronchoconstriction caused by several kinds of challenge, such as the response to sulphur dioxide, exercise and cold air. 'Accolate' attenuates the early and late phase inflammatory reaction caused by various antigens such as grass, cat dander, ragweed and mixed antigens.

In asthmatic patients not adequately controlled by beta-agonist therapy (given as required) 'Accolate' improves symptoms (reducing daytime and nocturnal asthmatic symptoms), improves lung function, reduces the need for concomitant beta-agonist medication and reduces incidence of exacerbations. Similar benefits have been seen in patients with more severe asthma receiving high dose inhaled steroids.

In clinical studies, there was a significant first-dose effect on baseline bronchomotor tone observed within 2 hours of dosing, when peak plasma concentrations had not yet been achieved. Initial improvements in asthma symptoms occurred within the first week, and often the first few days, of treatment with 'Accolate'.

Peak plasma concentrations of zafirlukast are achieved approximately 3 hours after oral administration of 'Accolate'.

Administration of 'Accolate' with food increased the variability in the bioavailability of zafirlukast and reduced bioavailability in most (75%) subjects. The net reduction was approximately 40%.

Following twice-daily administration of 'Accolate' (30 to 80 mg bd), accumulation of zafirlukast in plasma was low (not detectable - 2.9 times first dose values; mean 1.45; median 1.27). The terminal half-life of zafirlukast is approximately 10 hours. Steady-state plasma concentrations of zafirlukast were proportional to the dose and predictable from single-dose pharmacokinetic data.

Zafirlukast is extensively metabolised. Following a radiolabelled dose the urinary excretion accounts for approximately 10% dose and faecal excretion for 89%. Zafirlukast is not detected in urine. The metabolites identified in human plasma were found to be at least 90-fold less potent than zafirlukast in a standard in-vitro test of activity.

Zafirlukast is approximately 99% protein bound to human plasma proteins, predominantly albumin, over the concentration range 0.25 to 4.0 microgram/ml.

Pharmacokinetic studies in special populations have been performed in a relatively small number of subjects, and the clinical significance of the following kinetic data is not established.

Pharmacokinetics of zafirlukast in adolescents and adults with asthma were similar to those of healthy adult males. When adjusted for body weight, the pharmacokinetics of zafirlukast are not significantly different between men and women.

Elderly subjects and subjects with stable alcoholic cirrhosis demonstrated an approximately two-fold increase in C_max and AUC compared to normal subjects given the same doses of 'Accolate'.

There are no significant differences in the pharmacokinetics of zafirlukast in patients with mild renal impairment and in normal subjects. However, there are no conclusive data available in patients with moderate or severe renal impairment, hence the recommendation for caution is used in this patient population.

After multiple doses of greater than 40 mg/kg/day for up to 12 months, liver enlargement associated with degenerative/fatty change or glycogen deposition was seen in rats, mice and dogs. Histiocytic aggregates were seen in a number of tissues of dogs.

Male mice given 300 mg/kg zafirlukast daily had an increased incidence of hepatocellular adenomas compared to control animals. Rats given 2000 mg/kg zafirlukast daily had an increased incidence of urinary bladder papilloma compared to control animals. Zafirlukast was not mutagenic in a range of tests. The clinical significance of these findings during the long term use of 'Accolate' in man is uncertain.

There were no other notable findings from the pre-clinical testing.

Croscarmellose sodium

Hypromellose E464

Lactose Monohydrate

Magnesium Stearate E572

Microcrystalline Cellulose E460

Povidone

Titanium Dioxide E171

None known

3 years

Do not store above 30^oC.

Aluminium laminate/foil blister packs containing 56 or 100 tablets.

No special precautions.

AstraZeneca UK Limited,

600 Capability Green,

Luton, LU1 3LU, UK.

PL 17901/0001

1 June 2000

2^nd May 2008