Terbutaline in children with asthma

Focal Seizures in a Child Receiving Terbutaline Sulfate: A Case Report

Terbutaline sulfate is a beta-adrenergic receptor agonist. More specific for B2 receptors, it is used as a bronchodilator in asthma. Its known side effects can include dizziness, tremors, and tachycardia. However, seizures are not among the commonly reported side effects. This is the case of a five-month-old girl who presented with focal seizures after the intake of terbutaline sulfate syrup. Other causes of the seizures were excluded through history and investigations, including an EEG and electrolyte panel. The seizures stopped on cessation of the terbutaline sulfate with no recurrence, leading us to believe that the focal seizures were an adverse effect of the terbutaline sulfate. A high index of suspicion for drug-related adverse effects should therefore be kept for a child with new onset focal seizures.

Plasma terbutaline levels in asthma

Plasma terbutaline levels and peak expiratory flow rates were measured in 5 asthmatic children using doses of 0.25 and 0.075 mg/kg. The higher dose resulted in safe, non-toxic plasma levels and returned the peak expiratory flow rate to normal. This dose (maximum 5 mg) is safe in children.

Terbutaline in the treatment of acute asthma in childhood

Forty-eight children with known asthma (ranging in age from 2 to 16 years) were studied during an acute attack. Each received either terbutaline or epinephrine subcutaneously in a random double-blind fashion. Measurement of heart rate, respiratory rate, and systemic arterial systolic and diastolic blood pressures and careful clinical assessment of obstruction of the airway were made before and at 15, 30, and 60 minutes after the administration of the drugs. Appreciable and significant clinical improvement was noted in 19 of the 24 patients in both groups and was of comparable magnitude. A small, but significant, increase in heart rate was noted in those patients requiring only one injection of terbutaline, suggesting that the drug's selectivity for the lung is relative not absolute. The present study demonstrates that terbutaline is an effective bronchodilator drug in acute childhood asthma.

Terbutaline in the treatment of status asthmaticus

The effect of administration of terbutaline on the pulmonary and cardiovascular systems was studied in ten children with status asthmaticus. Terbutaline (0.01 to 0.04 mg/kg of body weight) was given subcutaneously in multiple doses. A significant decrease in respiratory rate and in arterial blood pressure, with no significant change in cardiac rate, was seen only after the first dose of terbutaline. There was a decrease in mean arterial carbon dioxide tension and an increase in mean arterial oxygen pressure. There was gross clinical improvement following administration of terbutaline in nine of the ten patients. One patient who failed to respond to administration of terbutaline also failed to respond to intravenously administered isoproterenol. We conclude that terbutaline is effective in the treatment of status asthmaticus, with only modest effects on the cardiovascular system.

Cardiopulmonary effects of long-term bronchodilator administration

Because of reports of drug tolerance occurring with chronic use of adrenergic agents in asthma, we investigated cardiopulmonary responsiveness to ephedrine and to the beta-2 agent, tebutaline, following chronic drug administration for periods up to one year. With chronic drug administration baseline (prior to daily medication) FEV increased 19% in the terbutaline group and 3.5% in the ephedrine group. An additional increase of FEV above baseline of 23% for terbutaline and 12% for ephedrine was noted after daily medication. Terbutaline also had a longer duration of effect; peak response after ephedrine occurred at 2 hr while terbutaline effect was maximal at 3 to 4 hr. There was no evidence for reduced responsiveness to the bronchodilator actions of either drug at any time. Despite prolonged use, both drugs continue to increase heart rate and pulse pressure moderately following ingestion, with a peak effect occurring at 3 hr; however, pulse pressure widened after terbutaline because of a diastolic fall, while the major effect of ephedrine was to increase systolic pressure. Baseline blood pressure, particularly diastolic, declined progressively with continued drug use. No evidence of cardiac, ehpatic, renal, or ophthalmologic toxicity or change in need for other bronchodilator agents was noted during the study with either drug.

A long-term study of low-dose aerosolized terbutaline sulfate

The purpose of this study was to evaluate the safety and efficacy of a new lowdose terbutaline sulfate aerosol (375 micrograms) over a six-week period. The question of drug tolerance was also evaluated. Twenty-four ambulant patients with chronic obstructive pulmonary disease with a component of reversible airway disease was evaluated. The patients were tested at two-week intervals during a six-week period. The patients abstained from all bronchodilatory medications for at least 10 hours prior to the time of evaluation. The evaluation consisted of baseline FEV1 and MMEFR determinations, ECG, CBC, urinalysis, and renal and liver function tests. After the terbutaline was administered, a rhythm strip and pulmonary function tests were repeated at 5, 15, 30, 60, 120, and 180 minutes. Throughout the six-week study there was a statistically significant increase in FEV1 and MMEFR, (P less than 0.001). No change was noted in the systolic blood pressures; however, heart rate and diastolic blood pressure decreased significantly. No drug tolerance, paradoxical bronchospasm, subjective side effects, no abnormal laboratory results were noted during the study period.