Management of Asthma

The asthma means bronchospasm and for its effective management we need bronchospasm relaxants. There are a variety of preparations containing sympathomimetics in the form of aerosols, inhalations, tablets and syrups capable of producing bronchodilations by stimulating b₂-adrenergic receptors in the bronchial smooth muscle. The choice and mode of treatment depends on the age of patient and severity of asthmatic conditions. Inhalations and aerosols may not be convenient mode of treatment in infants and children. Salbutamol and terbutaline are relatively selective drugs for b₂-adrenergic receptors. These produce optimal bronchodilations at lower concentration than those required to stimulate b₁-adrenergic cardiostimulatory receptors. Respiratory stimulants like doxapram and nikethamide are of no value and may be harmful in cases of asthma. As per the experience of a close friend of mine, sympathomimetics like salbutamol and terbutaline produce immediate relief in reversible bronchospasm associated with asthma and allergic bronchitis. Excessive and long term use of these drugs may cause cardiac arrhythmias.

Xanthine derivative drugs such as aminophylline, theophylline and etophylline are known to produce smooth muscle relaxation and bronchodilation by inhibiting the enzyme phosphodiesterase which leads to an increase in the intracellular levels of cAMP. Xanthine derivatives also produce diuresis (increase in the urinary output) and cardiopulmonary stimulation. Corticosteroids as aerosol inhalation help to reduce the mucosal edema, hypersecretion of mucous and bronchial hypersensitivity. Corticosteroids act by preventing the release of phospholipids from cell membranes in the lungs and their anti-inflammatory action helps to underplay the mediators of inflammation. Oral corticosteroid therapy should be reserved for acute exacerbations and chronic cases but after the radiological evaluation of lungs and investigations of sputum for Mycobacterium tuberculosis (tubercle bacilli or TB) and other bacterial or fungal infections. Asthmatic patients should avoid total dependence on aerosols or inhalations and should ask their physicians to prescribe them oral drugs also for emergency use. A combination of salbutamol and aminophylline or theophylline as tablets or syrup is a reliable form of treatment for asthma advisable under the guidance of a medical practitioner only.