terbutaline sulfate: clinical use

Prescribing considerations

• Check inhaler technique and investigate increasing reliever use or reduced response.
• For persistent asthma, ensure appropriate anti-inflammatory therapy is prescribed and continued; do not use terbutaline as inhaled reliever monotherapy.
• Use caution with thyrotoxicosis, diabetes and significant cardiovascular disease.
• Specialist oversight is required for home nebulised rescue treatment in children and adolescents.
• Obstetric use requires experienced clinicians, continuous maternal and fetal assessment, and appropriate facilities.

Contraindications and cautions

• Hypersensitivity to terbutaline or a formulation excipient.
• Do not use the injection for tocolysis outside the licensed gestational window or where prolonging pregnancy would endanger the mother or fetus.
• Tocolysis is contraindicated with pre-existing ischaemic heart disease, significant ischaemic risk, threatened early-pregnancy loss and specified serious maternal, fetal or placental conditions.
• Avoid where beta-mimetic effects would be harmful, including hypertrophic obstructive cardiomyopathy or left ventricular outflow obstruction.

Monitoring

• Clinical response, reliever use and inhaler technique.
• Serum potassium in acute severe asthma or with potassium-depleting treatments.
• Blood glucose in people with diabetes or during intensive treatment.
• During obstetric infusion: maternal cardiovascular status, ECG, fluid balance, electrolytes, glucose and lactate, with fetal monitoring where appropriate.
• Consider lactate measurement if respiratory distress persists despite apparently adequate intensive nebulised or parenteral bronchodilation.

Clinical pharmacology

A relatively selective beta2-adrenoceptor agonist producing bronchial and uterine smooth-muscle relaxation. Systemic effects can include tremor, tachycardia, hyperglycaemia and intracellular potassium shift; exposure and adverse effects vary by route.

Formulation and product differences

• Turbohaler is a breath-actuated dry-powder inhaler requiring a strong, deep inhalation. It contains lactose that may include traces of milk protein.
• Respules are a sterile nebuliser solution for severe bronchospasm; high-intensity nebulised treatment has been associated with hypokalaemia and lactic acidosis.
• Tablets provide systemic oral treatment, contain lactose and the selected product is discontinued.
• Injection is for professional administration and is the only selected formulation with the restricted premature-labour indication.

Inhaled preparation

Route: Inhaled

Strengths: 0.5 mg/dose, 2.5 mg/mL

Tablet

Route: Oral

Strengths: 5 mg

Injection

Route: Parenteral

Strengths: 0.5 mg/mL