Sympathomimetics Drugs

The sympathomimetics constitute a very important group of drugs used for cardiovascular, respiratory, and other conditions.

They are readily divided into subgroups on the basis of their spectrum of action (α-, β-, or dopamine-receptor affinity) or mode of action (direct or indirect).

 

Sympathomimetics Drugs

 

Subclass

Noncatecholamines

Phenylephrine

  • Mechanism of Action

α1, α2 agonist

  • Clinical Applications

Decongestant, mydriatic, neurogenic hypotension

  • Pharmacokinetics

Oral, inhalant, topical, and parenteral • Duration: 15–60 min

  • Toxicities, Interactions

Hypertension, stroke, myocardial infarction


 

Subclass

Noncatecholamine β-selective

Albuterol, metaproterenol, terbutaline

  • Mechanism of Action

β2 agonist

  • Clinical Applications

Prompt onset for acute bronchospasm

  • Pharmacokinetics

Inhalant via aerosol canister • Duration: 2–6 h

  • Toxicities, Interactions

Tachycardia, tremor


 

Subclass

Indirect-acting phenylisopropylamines

Amphetamine,

methamphetamine

  • Mechanism of Action

Displaces stored catecholamines from nerve endings

  • Clinical Applications

Anorexiant, ADHD, narcolepsy

  • Pharmacokinetics

Inhalant via aerosol

Oral and parenteral • Duration: ≥4–6 h

  • Toxicities, Interactions

High addiction liability. Paranoia, aggression; insomnia; hypertension


 

Subclass

Cocaine

Cocaine

  • Mechanism of Action

Blocks norepinephrine reuptake (NET) and dopamine reuptake (DAT)

  • Clinical Applications

Local anesthetic with intrinsic hemostatic action

  • Pharmacokinetics

Parenteral only ,Duration: 2 h

  • Toxicities, Interactions

Very high addiction ,liability. Hypertension, arrhythmias, seizures


 

Subclass

Tyramine

Tyramine

  • Mechanism of Action

Displaces stored catecholamines

  • Clinical Applications

No clinical use but found in fermented foods

  • Pharmacokinetics

Parenteral only ,Duration: 2 h

  • Toxicities, Interactions

Hypertension, arrhythmias, stroke, myocardial infarction.

Leave a Reply