A nebuliser makes an aerosol by blowing air or oxygen through a solution of a drug. Many inhaled drugs such as salbutamol, ipratropium and corticosteroids such as beclomethasone can be given in this way. It has the advantage over a metered dose inhaler (MDI) that no special effort is required to coordinate breathing, and a nebuliser allows a much greater volume of the drug to be delivered to where it is needed (the airways) compared with that of MDIs. The safety profile of anti-asthmatic drugs such as salbutamol is extremely high and the high doses necessarily given by nebulization are generally well-tolerated.