Veterinary Neuropharmacology

CLASSIFICATION OF SYMPATHOMIMETIC DRUGS

Sympathomimetic drugs are classified as follows

• Direct acting (Adrenergic agonists)
• These are agents that act directly either on alpha (alpha1 and alpha 2) or beta (beta1 and 2 ) adrenoceptors.
• Drugs having equal potency at α and β receptors. Eg. Epinephrine, Ephedrine, Dopamine
• Drugs having higher potency at α receptors. Eg. Norepinephrine
• Selective α receptor agonists. Eg. Phenylephrine and Methoxamine (alpha 1), Clonidine (alpha 2)
• Nonselective β receptor agonist. Eg. Isoproterenol
• Selective β1 agonist. Eg. Dobutamine
• Selective β2 agonists. Eg. Metaproterenol, Terbutaline, Salbutamol
• Indirect acting
  • Drugs inducing release of neurotransmitter. Eg. Amphetamine, Tramine, Ephedrine
  • Drugs inhibiting reuptake of neurotransmitter. Eg. Cocaine, Imipramine
  • Drugs inhibiting monoamine oxidases. Eg. Pargyline, Clorgyline
  • Drugs inhibiting catechol-o-methyl transferase. Eg. Pyragallol