st and even death may be associated with abuse of VENTOLIN HFA. Treatment consists of discontinuation of VENTOLIN HFA together with appropriate symptomatic therapy. The judicious use of a cardioselective beta-receptor blocker may be considered, bearing in mind that such medication can produce bronchospasm. There is insufficient evidence to determine if dialysis is beneficial for overdosage of VENTOLIN HFA.
The oral median lethal dose of albuterol sulfate in mice is greater than 2,000 mg/kg (approximately 6,800 times the maximum recommended daily inhalation dose for adults on a mg/m2 basis and approximately 3,200 times the maximum recommended daily inhalation dose for children on a mg/m2 basis). In mature rats, the subcutaneous median lethal dose of albuterol sulfate is approximately 450 mg/kg (approximately 3,000 times the maximum recommended daily inhalation dose for adults on a mg/m2 basis and approximately 1,400 times the maximum recommended daily inhalation dose for children on a mg/m2 basis). In young rats, the subcutaneous median lethal dose is approximately 2,000 mg/kg (approximately 14,000 times the maximum recommended daily inhalation dose for adults on a mg/m2 basis and approximately 6,400 times the maximum recommended daily inhalation dose for children on a mg/m2 basis). The inhalation median lethal dose has not been determined in animals.
11 DESCRIPTION
The active component of VENTOLIN HFA is albuterol sulfate, USP, the racemic form of albuterol and a relatively selective beta2-adrenergic bronchodilator. Albuterol sulfate has the chemical name α1-[(tert-butylamino)methyl]-4-hydroxy-m-xylene-α, α′-diol sulfate (2:1)(salt) and the following chemical structure:
Image from Drug Label Content
Albuterol sulfate is a white crystalline powder with a molecular weight of 576.7, and the empirical formula is (C13H21NO3)2•H2SO4. It is soluble in water and slightly soluble in ethanol.
The World Health Organization recommended name for albuterol base is salbutamol.
VENTOLIN HFA is a pressurized metered-dose aerosol unit fitted with a counter. VENTOLIN HFA is intended for oral inhalation only. Each unit contains a microcrystalline suspension of albuterol sulfate in propellant HFA-134a (1,1,1,2-tetrafluoroethane). It contains no other excipients.
Priming VENTOLIN HFA is essential to ensure appropriate albuterol content in each actuation. To prime the inhaler, release 4 sprays into the air away from the face, shaking well before each spray. The inhaler should be primed before using it for the first time, when it has not been used for more than 2 weeks, or when it has been dropped.
After priming, each actuation of the inhaler delivers 120 mcg of albuterol sulfate, USP in 75 mg of suspension from the valve and 108 mcg of albuterol sulfate, USP from the mouthpiece (equivalent to 90 mcg of albuterol base from the mouthpiece).
Each 18-g canister provides 200 inhalations.
This product does not contain chlorofluorocarbons (CFCs) as the propellant.
12 CLINICAL PHARMACOLOGY
12.1 Mechanism of Action
In vitro studies and in vivo pharmacologic studies have demonstrated that albuterol has a preferential effect on beta2-adrenergic receptors compared with isoproterenol. While it is recognized that beta2-adrenergic receptors are the predominant receptors in bronchial smooth muscle, data indicate that there is a population of beta2-receptors in the human heart existing in a concentration between |
