Terbutaline

From Anvita Health Wiki

Contents 1 Introduction 2 Indications 3 Contraindications 4 Dosage 5 Pharmacokinetics 6 Adverse-effects 7 Drug-interactions 8 Mechanism-of-action 9 More General Terms 10 Internet Database 11 References

Introduction

• Tradenames: Brethine, Bricanyl, Brethaine.

Indications

• chronic obstructive pulmonary disease ( COPD)
• asthma
• bronchospasm

Contraindications

• management of preterm labor (potential for maternal heart problems & death) [4]
  

• pregnancy category = b
• safety in lactation = -

Dosage

• 0.25 mg SC; may repeat in 15 minutes; hourly max: 0.5 mg
• inhaler: 2 puffs every 4-6 hours
• oral: 2.5-5 mg PO TID-QID; max 15 mg/day
• children 12-15 yo: 2.5 mg PO TID. <12 yo: DO NOT USE

• Tabs: 2.5 & 5 mg.
• Aerosol: 0.2 mg/actuation (10.5 g)
• Injection: 1 mg/mL (1 mL). Dose adjustment in renal failure:

*  creatinine clearance          dosage 
*    10-50 mL/min                 50% 
*     < 10 mL/min                avoid usage

Pharmacokinetics

• subcutaneous

• well absorbed
• onset of action 15 minutes
• duration of action: 60-240 minutes

• oral

• 50% absorbed
• largely metabolized by 1st pass hepatic metabolism
• onset of action: 30 minutes
• duration of action: 4-8 hours

• metabolized by the liver
• eliminated in the urine
• complete elimination is seen 2-3 days after a single dose
  

• elimination via liver

Adverse-effects

• common (> 10%)

• nervousness, restlessness, trembling

• less common (1-10%)

• dizziness, drowsiness, dry mouth, tachycardia, headache, diaphoresis, hypertension, muscle cramps, nausea/vomiting, insomnia, weakness, bad taste in mouth

• uncommon (< 1%)

• chest pain, cardiac arrhythmias, paradoxical bronchospasm

• other

• palpitations
• tremor
• hypokalemia
  
• drug adverse effects of adrenergic receptor agonists
• drug adverse effects of beta-adrenergic receptor agonists

Drug-interactions

• beta blockers: antagonize effects of terbutaline
• MAO inhibitors, tricyclic antidepressants: increase cardiovascular toxicity
  
• drug interaction(s) of beta-2 adrenergic receptor agonists with beta adrenergic receptor antagonists
• drug interaction(s) of beta-2 adrenergic receptor agonists with loop diuretics
• drug interaction(s) of beta-2 adrenergic receptor agonists with thiazide diuretics

Mechanism-of-action

• beta-2 adrenergic receptor agonist
• relaxation of bronchial tree
• peripheral vasodilation
• relaxes GI & uterine smooth muscle
• high doses can cause tachycardia & CNS stimulation

More General Terms

• beta-2 adrenergic receptor agonist
• antiasthmatic agent

Internet Database

PubChem: 5403
PubChem: 31620
PubChem: 441334
PubChem: 657301

References

1. The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996
2. Drug Information & Medication Formulary, Veterans Affairs, Central California Health Care System, 1st ed., Ravnan et al eds, 1998
3. Kaiser Permanente Northern California Regional Drug Formulary, 1998
4. FDA MedWatch, Feb 17, 2011 Terbutaline: Label Change - Warnings Against Use for Treatment of Preterm Labor [1]

terbutaline (Brethine, Bricanyl, Brethaine)