Isoprenaline

Source: Wikipedia, the free encyclopedia.
Isoprenaline
INN: Isoprenaline
Clinical data
Trade namesMany[1]
Other namesIsoproterenol (USAN US)
MedlinePlusa601236
Pregnancy
category
  • AU: A
Routes of
administration		Inhalation (80–120 μg), intravenous injection (IV)
ATC code
Legal status
Legal status
  • AU: S4 (Prescription only)
  • In general: ℞ (Prescription only)
Pharmacokinetic data
Elimination half-life~2 minutes
Identifiers
  • (RS)-4-[1-hydroxy-2-(isopropylamino)ethyl]benzene-1,2-diol
JSmol)
  • CC(C)NCC(O)c1cc(O)c(O)cc1
  • InChI=1S/C11H17NO3/c1-7(2)12-6-11(15)8-3-4-9(13)10(14)5-8/h3-5,7,11-15H,6H2,1-2H3 checkY
  • Key:JWZZKOKVBUJMES-UHFFFAOYSA-N checkY
  (verify)

Isoprenaline, or isoproterenol, is a

epinephrine (adrenaline).[2]

Medical uses

It is used to treat

long QT refractory to magnesium and to treat patients with intermittent Torsades de Pointes refractory to treatment with magnesium.[3]

Historically, it was used to treat asthma via metered aerosol or nebulizing devices; it was also available in sublingual, oral, intravenous, and intramuscular formulations.[4] The U.S. National Asthma Education and Prevention Program Expert Panel recommends against its use as a nebulizer for acute bronchoconstriction.[5]

Isoprenaline can also ameliorate the impairment of intestinal stem cells mediated by β2-adrenoreceptors after chemotherapy.[6]

Contraindications

It should not be used in people with tachyarrhythmias (except in special circumstances),[7] tachycardia or heart block caused by digitalis poisoning, ventricular arrhythmias which require inotropic therapy, or with angina.[2]

Adverse effects

Adverse effects of isoprenaline include nervousness, headache, dizziness, nausea, visual blurring, tachycardia, palpitations, angina, Adams-Stokes attacks, pulmonary edema, hypertension, hypotension, ventricular arrhythmias, tachyarrhythmias, difficulty breathing, sweating, mild tremors, weakness, flushing, and pallor.[2] Isoproterenol has been reported to cause insulin resistance leading to diabetic ketoacidosis.[8]

Pharmacology

The adverse effects of isoprenaline are also related to the drug's cardiovascular effects. Isoprenaline can produce

cardiac arrhythmias.[4]

Pharmacodynamics

Isoprenaline is a

alpha adrenergic receptors at low levels.[4] However, at higher concentrations, isoprenaline can evoke α-AR-mediated responses.[9][10] Its agonist effects at TAAR1 provide it with pharmacodynamic effects that resemble those of the endogenous trace amines, like tyramine.[11]

Isoprenaline's effects on the

cardiovascular system (non-selective) relate to its actions on cardiac β1 receptors and β2 receptors on smooth muscle within the tunica media of arterioles. Isoprenaline has positive inotropic and chronotropic effects on the heart. β2 adrenoceptor stimulation in arteriolar smooth muscle induces vasodilation. Its inotropic and chronotropic effects elevate systolic blood pressure, while its vasodilatory effects tend to lower diastolic blood pressure. The overall effect is to decrease mean arterial pressure due to the β2 receptors' vasodilation.[12]

The

hydroxyl groups keep it susceptible to enzymatic metabolism.[13]

Pharmacokinetics

The plasma half-life for isoproterenol is approximately two to five minutes. It is degraded enzymatically via catechol O-methyltransferase (COMT) primarily in the liver and excreted in the urine as sulfated conjugates.[14][15]

Chemistry

It is structurally related to

epinephrine.[2]

History

It was first approved in the US in 1947.[4] Between 1963 and 1968 in England, Wales, Scotland, Ireland, Australia, and New Zealand there was an increase in deaths among people using isoprenaline to treat asthma. This was attributed to overdose: the inhalers produced in that area were dispensing five times the dosage dispensed by inhalers produced in the US and Canada, where the deaths were not observed.[16][17]

Society and culture

Brands

Isoprenaline is marketed under many brand names worldwide, including Aleudrina, Asthpul, Iludrin, Isomenyl, Isuprel, Neo-Epinine, Neodrenal, Proternol, and Saventrine.[1] It is also marketed as a combination drug with cromoglicic acid as Frenal Compositum, in combination with pronase as Isopal P, and in combination with atropine as Stmerin D.[1]

References

  1. ^ a b c "Isoprenaline international brands". Drugs.com. Archived from the original on June 26, 2019. Retrieved June 21, 2017.
  2. ^ a b c d e "Label: Isoproterenol hydrochloride injection, solution". NIH DailyMed. September 10, 2013. Retrieved June 21, 2017.
  3. PMID 29083738. NBK459388
    .
  4. ^
    ISBN 978-1-59259-654-6
    .
  5. ^ National Asthma Education and Prevention Program Expert Panel (August 28, 2007). "Expert Panel Report 3: Guidelines for the Diagnosis and Management of Asthma" (PDF). NIH National Heart, Lung, and Blood Institute.
  6. PMID 31648381
    .
  7. PMID 17612676
    .
  8. PMID 30647979
    .
  9. PMID 13062084
    .
  10. PMID 25606852
    .
  11. PMID 22073124
    . Table 1. EC50 values of different agonists at hTAAR1, hADRB1 and hADRB2
  12. ISBN 978-83-200-5368-5
    .
  13. ^ Mehta A (January 27, 2011). "Notes - Medicinal Chemistry of the Peripheral Nervous System - Adrenergics and Cholinergic". Pharmaxchange. Archived from the original on 4 November 2010. Retrieved June 21, 2017.
  14. S2CID 81053428
    .
  15. PMID 30252298. NBK526042
    .
  16. PMID 9919437
    .
  17. S2CID 31732029
    .
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