Terbutaline adverse effects

Terbutaline has been shown to prolong pregnancy but has not been associated with decreased neonatal morbidity.36 It is contraindicated for use in women with preexisting cardiac arrhythmia. Potentially serious adverse effects include pulmonary edema, cardiac arrhythmia, or myocardial ischemia in the mother. Reported fetal and neonatal adverse effects include tachycardia, hyperglycemia, and hyperinsulinemia.41... 

The calcium channel blockers have been associated with both prolonged pregnancy and decreased neonatal morbidity.36,42 when compared with P-mimetics (e.g., terbutaline) and magnesium, they show better neonatal outcome and a lower incidence of serious maternal side effects.42 Potential minor maternal adverse effects include headache, flushing, dizziness, and transient hypotension.41... 

One of the most important uses of sympathomimetic drugs is in the therapy of bronchial asthma. This use is discussed in Chapter 20. Nonselective drugs (epinephrine), -selective agents (isoproterenol), and B2-selective agents (albuterol, metaproterenol, terbutaline) all are available for this indication. Sympathomimetics other than the 32-selective drugs are now rarely used because they are likely to have more adverse effects than the selective drugs. 

Albuterol and terbutaline are also available in tablet form. One tablet two or three times daily is the usual regimen the principal adverse effects of skeletal muscle tremor, nervousness, and occasional weakness may be reduced by starting the patient on halfstrength tablets for the first 2 weeks of therapy. This route of administration presents no advantage over inhaled treatment and is thus rarely prescribed. 

INHALATIONAL- HALOTHANE TERBUTALINE, THEOPHYLLINE Cases of arrhythmias when these bronchodilators are co-administered with halothane Possibly due to sensitization of the myocardium to circulating catecholamines by the volatile anaesthetics to varying degrees Risk of cardiac events is higher with halothane. Desflurane is irritant to the upper respiratory tract, and t secretions can occur and are best avoided in patients with bronchial asthma. Sevoflurane is non-irritant and unlikely to cause serious adverse effects... 

Except for suppression of plasma butjrylchoUnester-ase, the adverse effects of bambuterol are those of a beta2-adrenoceptor agonist and are related to the plasma concentration of terbutaline. Plasma butjrylchoUnester-ase returns to control values about 2 weeks after stopping treatment (SEDA-22,188). 

Terbutaline is a selective beta2-adrenoceptor agonist, with a similar profile to salbutamol, and its adverse effects profile is similar to that of salbutamol at equivalent doses (SEDA-21,186) (SEDA-22,193). 

Nebulized terbutaline 5 mg has been compared with injected adrenaline (0.01 ml/kg of 1 1000 adrenaline to a maximum of 0.3 ml) in children with acute asthma. Those who received adrenaline had a significantly higher rate of adverse effects, 47 versus 11% (SEDA-21,186). 

Terbutaline is the N-f-butyl analogue of metaproterenol and, as such, would be expected to have a more potent p2-selectivity. When compared to metaproterenol, terbutaline has a threefold greater potency at the p2-receptor. Like metaproterenol, it is resistant to COMT and slowly metabolized by MAO, therefore having good oral bioavailability with similar onset and duration. Terbutaline is available as tablets and solutions for injection and inhalation. Adverse effects are similar to other... 

The use of subcutaneous sympathomimetic bronchodilator is indicated for the severe asthma attack that requires emergency treatment. Epinephrine and terbutaline are available for subcutaneous therapy and, in usual doses, are comparable in efficacy. By this route, terbutaline appears to be no more 3z selective than epinephrine and is reported to have more adverse effects (22). Aqueous suspension of epinephrine provides a longer duration of action. In status asthmaticus sympathomimetics are often not helpful. Intravenous aminophylline is the basic therapy in this setting. The acute therapy should be instituted with a loading dose, but this should be proportionally reduced if the patient has been on regular theophylline therapy. 

In 7 healthy subjects pretreatment with oral theophylline for at least 4 days significantly increased the fall in serum potassium levels and rises in blood glucose, pulse rate, and systolic blood pressure caused by an infusion of terbutaline. A study in children given slow-release formulations of both theophylline and terbutaline found no increases in reported adverse effects and simple additive effects on the control of their asthma. ... 

When used concomitantly with other sympathomimet-ics, terbutaline may potentiate the adverse cardiovascular effects of the other drugs however, as an aerosol bronchodilator (adrenergic-stimulator type), concomitant use may relieve acute bronchospasm in patients on long-term oral terbutaline therapy. 

Halothane is known to cause arrhythmias and it has been suggested that it may increase susceptibility to the adverse cardiac effect of beta-agonist bronchodilators, which can cause arrhythmias. Note that beta agonists such as terbutaline are sympathomimetics (see Table 24.1 , (p.879)), like adrenaline (epinephrine), which has also been shown to cause arrhythmias in the presence of halothane (see Anaesthetics, general + Inotropes and Vasopressors , p.99). 

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