Agonist of α and β receptors; positive ionotropic (contractility) and chronotropic (rate) on heart (β₁), vasoconstriction in vascular beds (α), and vasodilation in skeletal muscle blood vessels (β₂) which may lower TPR

tachycardia, arrhythmia, anxiety, hypertension, and acute pulmonary edema

Cardiac arrest (increases cardiac output), anaphylaxis

Agonist of α₁, α₂, and β₁ receptors but little effect on β₂; increases TPR and BP, positive ionotropic effect on heart

Ischemia, arrhythmias

Hypotension, ADHD, depression

Activates D₁ receptors causing vasodilation of renal, splanchnic, coronary, cerebral, and other resistance vessels. Activation of D₂ receptors suppresses norepinephrine release. Also activates β₁receptors in heart and at high concentrations α receptors leading to vasoconstriction. Regulates Na⁺ secretion and renal function.  Neurotransmitter in the CNS and is involved in reward system of addiction.

Hypotension at high doses

Parkinson’s disease (caused by a deficiency of dopamine in basal ganglia); Dopamine receptors are targets for antipsychotic drugs

α1 agonist; vasoconstriction = ↑ arterial resistance and ↓ venous capacity, ↑ stroke volume causes ↑ CO, ↑ BP may cause reflexive ↓ HR; α₁ r’s also constrict pupillary dilator muscle

hypertension

Decongestant, mydriatic (dilates pupil), can be used to increase BP

α₂ agonist; cause vasoconstriction when given locally, but systemically acts through CNS to decrease sympathetic tone and BP

Dry mouth, sedation

Drowsiness

Impaired ejaculation

hypertension

α agonist with affinity for α_2A receptor; promotes vasoconstriction of nasal mucosa

Hypotension (central Clonidine-like effect)

Topical decongestant

Potent β1 and β2 agonist, positive chronotropic and ionotropic effects, vasodilator = ↑ CO, ↓ TPR and ↓ BP

Tachycardia, dysrhythmias

Bradycardia, heart block

Β₁ agonist; activate β₁ receptors causing ↑ CO with less reflexive tachycardia because they do not activate vasodilator β₂ receptors

Hypertension, arrhythmias

Heart failure, cardiogenic shock

Indirect stimulation of the adrenergic receptor system by increasing the activity of noradrenaline at α- and β-receptors, ability to cross blood-brain barrier into CNS makes it a mild stimulant

Tachycardia, arrhythmias, various nervous system symptoms

Ma huang (herbal medicine) decongestant, bronchodilator, weight loss

Acts as both a norepinephrine transporter (NET) substrate and reuptake blocker, eliciting reverse transport and blocking normal uptake = ↑ NE in synaptic cleft; release of NE and some dopamine; similar to ephedrine but enters CNS more readily

Elevates CO and BP

CNS stimulation

Marked stimulant effect on mood and alertness and depressant effect on appetite

Pharmacologic effects and abuse potential are similar to amphetamine (p.141); Block NET-mediated NE reuptake and enhance NE signaling similar to cocaine (p. 133) ???

Nervousness, drowsiness, insomnia

ADHD, narcolepsy

Inhibits both norepinephrine and dopamine transporters; increases interstitial concentrations not only of norepinephrine, dopamine, serotonin, and glutamate; decreases GABA levels

Increase in BP and HR

Improves wakefulness in narcolepsy and some other conditions

Indirect sympathomimetic action caused by release of stored catecholamines = action similar to NE; readily metabolized by MAO in liver = high first-pass effect

Increase in BP

Hypertensive crisis

Patients treated with monoamine oxidase (MAO) inhibitors may have intensified Tyramine effect (must avoid Tyramine containing foods like cheese)

Inhibits transmitter reuptake at noradrenergic synapses; enters CNS and inhibits dopamine reuptake into neurons in the “pleasure centers” of the brain

Tachycardia, hallucinations, paranoid delusions; overdoses cause tachyarrhythmias and a marked ↑ BP, which can be life-threatening. CNS stimulation

Heavily abused drug - produces amphetamine-like”psychological effects that is shorter lasting and more intense

D₁ agonist; activates adenylyl cyclase; causes vascular smooth muscle relaxation

hypotension, reflex tachycardia, ↑ intraocular pressure

hypertension

D₂ agonists; inhibits adenylyl cyclase and interacts with other intracellular pathways; restores dopamine actions in the CNS

Orthostatic hypotension

Parkinson’s disease, prolactinemia