Disease relevance of Bitolterol

• This study indicates that bitolterol is more effective than isoproterenol in degree and duration of bronchodilatation in patients with advanced chronic obstructive pulmonary disease [1].
• The results of this retrospective study suggest that bitolterol is an effective and safe treatment in patients with conditions associated with reversible bronchospasm [2].

High impact information on Bitolterol

• The mean FEV1 response remained greater than 15% over zero time (baseline) for greater than or equal to 8 hours after medication with bitolterol on each of four monthly pulmonary function test days and 2 1/2 to 5 hours for isoproterenol [3].
• Mean percent increase in forced expiratory volume in 1 sec (FEV1) over baseline was higher for bitolterol than for albuterol at all test times up to 8 hr after a dose at which time 20% mean percent increase of FEV1 over baseline was still present in the bitolterol-treated patients [4].
• Animal studies indicate that bitolterol has significant beta 2-selectivity [5].
• The bronchodilator/heart rate ratio for bitolterol was 22 times that of isoproterenol and 6 times that of N-t-B or salbutamol suggesting greater selectivity for beta2 adrenoreceptors for bitolterol [6].
• The prolonged bronchodilator effect of bitolterol was attributed to high concentration of the ester in lung tissues and to its slow hydrolysis, gradually releasing the active catecholamine, N-t-B [6].

Biological context of Bitolterol

• In the cardiovascular studies in anesthetized dogs, chronotropic, inotropic and blood pressure effects of bitolterol were markedly reduced relative to its bronchodilator effect [6].
• The sc LD50 values for isoproterenol in 4- to 5-month-old, 500-600 g (heavy) and 1.5- to 2-month-old, 150-200 g (small) male Sprague-Dawley rats were 0.6 mg/kg and 1300 mg/kg, respectively, and values for bitolterol were 4 mg/kg and greater than 1800 mg/kg, respectively [7].

Anatomical context of Bitolterol

• The major radioactive components of the feces were bitolterol and tBA [8].
• Bitolterol was hydrolyzed in vitro to tBA by esterases found in various tissues including small intestine, liver, and plasma [9].
• 4. A part of bitolterol was hydrolysed to colterol in rat stomach, and bitolterol was more rapidly hydrolysed to colteral with homogenates of intestinal mucosa than with stomach homogenates in vitro [10].

Associations of Bitolterol with other chemical compounds

• The metabolism and disposition of bitolterol, the di-p-toluate ester of N-t-butylarterenol (tBA) was studied in man after a single oral dose and in dog after intraduodenal, iv, or oral administration [8].
• Salmeterol (Serevent) is an inhaled beta 2-receptor agonist with more than twelve hours' effect duration compared with 4-6 hours for the more short-acting substances bitolterol, fenoterol, salbutamol, and terbutaline [11].

Gene context of Bitolterol

• The prolonged bronchodilator activity of bitolterol is due to the slow release of the ester from lung and hydrolysis to tBA, an active beta2-adrenoceptor agonist [8].

Analytical, diagnostic and therapeutic context of Bitolterol

• The optimal dose of bitolterol administered by CPIF was determined to be 1.0 mg which is similar to the dose of bitolterol recommended for use by metered-dose inhaler (MDI) which is 0.7 mg to 1.1 mg [12].
• Microencapsulation of bitolterol for controlled release and its effect on bronchodilator and heart rate activities in dogs [13].
• THEO was compared with 3 puffs every 8 h (6 A.M., 2 P.M., and 10 P.M.) of bitolterol (BITOL), a long-acting beta 2-agonist, in a randomized, double-blind, placebo-controlled cross-over study [14].
• Bitolterol has a much longer duration of action and should be considered as a suitable bronchodilator for regular nebulizer treatment of chronic asthma [15].

References