Terbutaline
Mechanism :
Terbutaline is a beta-adrenergic receptor agonist. Terbutaline exerts a preferential effect on beta 2-adrenergic receptors which are the predominant receptors in bronchial smooth muscle.
Indication :
Contraindications :
Contraindicated in patients known to be hypersensitive to sympathomimetic amines or any component of this drug product.
Dosing :
Oral:
<12 years: 0.05 mg/kg 3 times a day. Increase as needed. Max: 5 mg/day.
12-15 years: 2.5 mg 3 times a day. Max: 7.5 mg/day.
>15 years: 5 mg/dose 3 times a day initially, then reduce to 2.5 mg every 6 hours. Max: 15 mg/day.
SC:
<12 years: 0.005-0.01 mg/kg (Max: 0.4 mg) every 15-20 mins, for 3 doses. Then every 2-6 hours as needed.
>12 years: 0.25 mg every 15-30 mins for 3 doses as and when needed. Max: 0.5 mg/hour.
Adverse Effect :
Side effects include tremor, headache, nervousness, restlessness, transient hypoglycaemia, dizziness, drowsiness, insomnia, dry mouth, nausea/vomiting, muscle cramps, bad taste, diaphoresis, cardiac arrhythmias, pulmonary edema, myocardial ischemia, tonic cramp, palpitations and hypokalemia.
Interaction :
Monoamine Oxidase Inhibitors or Tricyclic Antidepressants: Terbutaline should be administered with extreme caution to patients being treated with monoamine oxidase inhibitors or tricyclic antidepressants, or within 2 weeks of discontinuation of such agents, since the action of terbutaline on the vascular system may be potentiated.
Beta-Blockers: Beta-adrenergic receptor blocking agents not only block the pulmonary effect of beta-agonists, but may produce severe bronchospasm in asthmatic patients.
Diuretics: The ECG changes and/or hypokalemia that may result from the administration of nonpotassium-sparing diuretics, such as loop or thiazide diuretics, can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | 50% of normal parenteral dose. Other routes Dose as in normal renal function |
| 10-20 | 50% of normal parenteral dose. Other routes. Dose as in normal renal function |
| <10 | Avoid parenteral dose. Other routes Dose as in normal renal function |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Likely dialysability. Dose as in GFR<10 mL/min |
| HD | Likely dialysability. Dose as in GFR<10 mL/min |
| HDF/High flux | Likely dialysability. Dose as in GFR<10 mL/min |
| CAV/VVHD | Likely dialysability. Dose as in GFR=10–20 mL/min |
Hepatic Dose :
No dose adjustment recommended.