Action And Clinical Pharmacology: In vitro and in vivo animal studies have shown that cromolyn sodium inhibits sensitized mast cell degranulation which occurs after exposure to specific antigens. It acts by inhibiting the release of mediators from mast cells. Studies show that cromolyn sodium indirectly blocks calcium ions from entering the mast cell, thereby preventing mediator release.
Cromolyn sodium inhibits both the immediate and nonimmediate bronchoconstrictive reactions to inhaled allergens. Cromolyn sodium also attenuates bronchospasm caused by exercise, toluene diisocyanate, ASA, cold air, sulfur dioxide and environmental pollutants in some patients.
Cromolyn sodium has no intrinsic bronchodilator, antihistaminic, or anti-inflammatory activity.
Indications And Clinical Uses: As an adjunct in the management of intrinsic and extrinsic asthma. It is used on a continuous basis to prevent symptoms associated with asthma.
Also indicated for use in the prevention of bronchospasm induced by known precipitating factors such as exercise, cold air, allergens and environmental pollutants.
Contra-Indications: Hypersensitivity to components of this product.
Manufacturers’ Warnings In Clinical States: Cromolyn sodium has no role in the treatment of an acute attack of asthma, especially status asthmaticus.
Severe anaphylactic reactions can occur after cromolyn sodium administration. The recommended dosage should be decreased in patients with decreased renal or hepatic function. Cromolyn sodium should be discontinued if the patient develops eosinophilic pneumonia (or pulmonary infiltrates with eosinophilia).
The number of cromolyn sodium sterules to be inhaled per day should be specified to the patient. Regular dosage is important and treatment must not be discontinued abruptly, especially when benefit has been obtained. If troublesome symptoms occur, particularly breathlessness at rest, no benefit is likely to be obtained by increasing the dosage above 8 sterules a day and the patient should be advised to consult a physician immediately, so that additional measures can be instituted if necessary.
Precautions: Mild throat irritation, coughing and transient bronchospasm may occur. Very rarely, severe bronchospasm associated with a marked fall in pulmonary function has been reported. In such cases, treatment should be stopped and should not be reintroduced.
Possible immunologic changes resulting in reactions such as polymyositis, pneumonitis and heart failure, urticaria and anaphylaxis have been reported.
Pregnancy : There are no adequate and well controlled studies in pregnant women. However, during clinical use there have been, to date, no reports of adverse effects on the fetus which could be ascribed to the use of cromolyn sodium. Nevertheless as with all medications, caution must be exercised during pregnancy.
Lactation : It is not known whether this drug is excreted in human milk; therefore, caution should be exercised when cromolyn sodium is administered to a nursing woman, and the attending physician must make a benefit/risk assessment in regard to its use in this situation.
Adverse Reactions: In controlled clinical studies, the most frequently reported adverse reactions attributed to cromolyn sodium treatment were: throat irritation or dryness, bad taste, cough, wheeze and nausea.
Bronchospasm [sometimes severe, associated with precipitous fall in pulmonary function (FEV1)], laryngeal edema (rare), nasal congestion (sometimes severe) and pharyngeal irritation have been reported.
Adverse reactions which occur infrequently and are associated with administration of the drug are: anaphylaxis, angioedema, dizziness, dysuria and urinary frequency, joint swelling and pain, lacrimation, headache, rash, swollen parotid gland, urticaria, pulmonary infiltrates with eosinophilia, substernal burning and myopathy.
The following adverse reactions have been reported as rare events and it is unclear whether they are attributable to the drug: anemia, exfoliative dermatitis, hemoptysis, hoarseness, myalgia, nephrosis, periarteritic vasculitis, pericarditis, peripheral neuritis, photodermatitis, sneezing, drowsiness, nasal itching, nasal bleeding, nasal burning, serum sickness, stomach ache, polymyositis, vertigo and liver disease.
Symptoms And Treatment Of Overdose: Symptoms and Treatment: There have been no reported cases in humans of overdosage of the drug. Symptomatic treatment is suggested should overdosage occur.
Dosage And Administration: Cromolyn sodium in a plastic sterule contains 2 mL of a sterile 1% cromolyn sodium USP solution in water (20 mg cromolyn sodium in 2 mL water). It is recommended for use in a power operated nebulizer operated at an air flow rate of 6 to 8 L per minute and equipped with a suitable face mask.
The sterules are an alternative presentation of cromolyn sodium for those patients (including young children) who are unable to inhale the drug in powder form.
Adults and Children: The sterules are used on a continuous basis to prevent the symptoms of asthma and have no role in the treatment of acute attacks.
Initial Treatment: 1 sterule 4 times daily at 4 to 6 hourly intervals. In more severe cases, or during periods of high antigen challenge, the interval between doses may be reduced to 3 hours (i.e., up to 8 sterules daily may be taken).
For protection against bronchospasm induced by exercise, cromolyn sodium should be used 15 to 30 minutes before-hand.
Maintenance Therapy: When adequate response has been obtained, the frequency of inhalations may be reduced to 1 sterule every 8 to 12 hours (i.e., 2 or 3 sterules per day). If chest symptoms are troublesome at night, it is important that the final dose be taken, if awakened during the night.
Patients should be warned against suddenly discontinuing therapy when symptoms have been partially or completely controlled by the sterules.
Concomitant Therapy: Other asthma therapy should be continued until clinical improvement permits a progressive reduction in dosage. However, cromolyn sodium therapy alone may prevent symptoms of mild to moderate asthma, especially in children and young adults.
In severe asthma, particularly in older patients, cromolyn sodium therapy alone is insufficient to prevent symptoms. In a proportion of such cases, significant improvement can be obtained by combining cromolyn sodium with corticosteroid therapy even when inadequate relief is obtained from either drug alone.
In steroid-dependent patients, the addition of cromolyn sodium to the regimen may permit a slow, progressive and significant reduction in the maintenance dose of steroids.
Reduction or Withdrawal of Corticosteroids: The dangers of sudden withdrawal of corticosteroids are well recognized, particularly in steroid treated patients who have received long-term administration of oral steroids or injections of adrenocorticotrophic hormone (ACTH).
When the physician attempts to reduce the corticosteroid dosage, it is important that the reduction should be gradual and that close surveillance and frequent examination of the patient is maintained. It should be remembered that the adrenal cortex is suppressed by the administration of oral steroids, and that in both oral steroid and ACTH therapy, the ability of the patient to react to stress is usually impaired. In such patients, acute renal insufficiency and severe asthma can be precipitated by an increase in stress and/or reduction or withdrawal of either steroid or ACTH therapy. In order to identify such a risk in patients who have received long-term steroid therapy and where substantial reduction or complete withdrawal of corticosteroids is contemplated, it is advisable to assess adrenal and pituitary function.
Method of Reducing Steroid Dosage: The reduction in the daily maintenance dose of steroids should be stepwise at a suggested rate equivalent to about 1% per day (e.g., a maintenance dose of 10 mg prednisolone per day is reduced to 9 mg/day after 1 week). The gradual reduction should be continued until either the patient cannot tolerate a further reduction or it is found possible to withdraw corticosteroids completely.
Note: If troublesome symptoms recur during the period of reduction, the daily dose should be raised immediately. A larger increase in the steroid dose may be essential at times as a temporary measure, to control a severe relapse induced by antigen challenge, infections or stress. The increased physical or mental activity resulting from subjective improvement can also constitute a stress. When symptoms are brought under control, a progressive reduction may be attempted as before.
Method of Withdrawing ACTH: The same principles apply as discussed above. In practice, either the number of units of ACTH per injection can be reduced, or the interval between injections can be extended (e.g., from 1 per day, to 1 on alternate days, to 1 biweekly).
Withdrawal of Therapy: As the action of cromolyn sodium is essentially preventive, continuity of therapy is important in patients who have gained benefit. If for any reason cromolyn sodium is withdrawn, a suggested regimen for withdrawal is to reduce the cromolyn sodium dosage gradually over a period of 1 week. It should be borne in mind that symptoms of asthma may recur when the drug is discontinued.
Caution: In such cases where cromolyn sodium has permitted a reduction in the maintenance dose of steroids, it is recommended that the steroid dose first be restored to at least the pre-cromolyn sodium level at the commencement of withdrawal of cromolyn sodium, followed by a slow reduction of the steroid dose to tolerance. This is to avoid risk of acute relapse. It is also recommended that adrenal function be assessed before restoring the pre-cromolyn sodium steroid dose.
Administration of Sterules: Administration by inhalation of the contents of an sterule is only possible with the use of the nebulizer unit.
Availability And Storage: Each mL of sterile solution contains: cromolyn sodium 1%. Nonmedicinal ingredients: purified sterile water. Sterules of 2 mL, cartons of 50. Store at room temperature (15 to 25°C) and protect from direct sunlight. Discard any unused sterules in opened foil packs after 3 months.
APO®-CROMOLYN STERULES Apotex Cromolyn Sodium Asthma Prophylaxis