Phm 350 - E2 - Ans Modulation: Clinical Use Of Sympathomimetics

Front 1

Major Therapeutic Applications of Adrenergic Agonists
Drugs are chosen for therapeutic use based on many factors. What are some?

Back 1

One factor is clearly targeting of the tissue where the desired effect must occur; another is that there should be few side effects.

Front 2

Different routes of administration may be chosen to?

Back 2

effectively target different organs with a drug and induce different therapeutic effects of a drug.

Front 3

What are the clinical uses of sympathomimetics targeting cardiac function for A-V block?

Back 3

A-V block, in which conduction of electrical signals through the node is slowed, perhaps so much that it is effectively blocked, so that contraction of atria and ventricles are not coordinated. Cardiac arrest, in which the heart stops all contractile activity. The recommended drugs increase A-V conduction and also increase heart rate and contractility to increase cardiac output (without inducing an increase of blood pressure).
isoproterenol, epinephrine

Front 4

What are the clinical uses of sympathomimetics targeting cardiac function for sinus bradycardia?

Back 4

Sinus bradycardia in which heart rate is lower than normal and this effect is induced due to malfunction of the S-A node (perhaps an excessive PNS input to the S-A node). The recommended drug increases heart rate by direct action in the S-A node.
isoproterenol, epinephrine

Front 5

What are the clinical uses of sympathomimetics targeting cardiac function for paroxysmal atrial tachycardia?

Back 5

Paroxysmal atrial tachycardia in which there is an increased heart rate driven by altered function in the atria. This altered atrial activity occurs spontaneously, without any obvious trigger. The actions of the recommended drugs are on the vasculature: drug-induced vasoconstriction (↑TPR) elevates blood pressure which will induce bradycardia - by reflex.
methoxamine, phenylephrine

Front 6

What are the clinical uses of sympathomimetics targeting cardiac function for cardiogenic shock?

Back 6

Cardiogenic shock, literally excessive low blood pressure (shock) arising from cardiac malfunction; perhaps most frequently occurring consequent to heart failure. The objective here is to target the heart to increase cardiac output to provide sufficient blood delivery throughout the body to maintain oxygen supply to all tissues and organs.
dopamine, dobutamine

Front 7

What are the clinical uses of sympathomimetics targeting cardiac function for Anaphylactic shock?

Back 7

Anaphylactic shock, literally excessive low blood pressure (resulting from excessive vasodilation) and bronchiole constriction (bronchospasm), arising from allergic reaction induced release of histamine. Heart is major target - bronchiole system is co-target - of drug therapy.
epinephrine, isoproterenol

Front 8

What are the clinical uses of sympathomimetics when acting locally as vasoconstrictors?

Back 8

Here, the drug is added close to the site of desired action - to maximize the desired effects at the site of administration and to minimize drug effects at other sites.

Front 9

What are the clinical uses of sympathomimetics when acting locally as vasoconstrictors for Decongestant action?

Back 9

the drug is sprayed into the nasal passages to target the blood vessels of the mucosa of the nasal passages. The resultant vasoconstriction and decreased blood flow reduces mucus production and secretion into the nasal passages and thus reduces nasal congestion.

DRUG: phenylephrine

Front 10

What are the clinical uses of sympathomimetics when acting locally as vasoconstrictors for Hemostatic action?

Back 10

the drug is applied in solution at the site of a hemorrhage to induce vasoconstriction and to reduce bleeding.

DRUG: epinephrine

Front 11

What are the clinical uses of sympathomimetics when acting locally as vasoconstrictors Hemostatic action?

Back 11

the drug is applied in solution with a local anesthetic; the hemostatic action is local vasoconstriction. The drug reduces blood flow around the injection site to reduce the rate of removal (in the blood) of the local anesthetic and thus prolongs the effect of the local anesthetic.

DRUG: epinephrine

Front 12

What are the clinical uses of sympathomimetics when acting systemically as vasoconstrictors?

Back 12

Cardiac arrest, anaphylactic shock, acute hypotension Here the drug is added intravenously to target blood vessels to induce vasoconstriction and increased blood pressure

DRUGS:
norepinephrine, phenylephrine

Here the drug is added intravenously - the target sites for the drugs are all those vessels which have alpha-1 receptors coupled to a contractile mechanism...to induce vasoconstriction and thus ↑TPR to counter excessive hypotension.

Front 13

What are the clinical uses of sympathomimetics targeting the bronchiole system?

Back 13

Asthma and some respiratory allergic reactions: the drug is usually administered as an aerosol to maximize targeting of the drug to the target cells and to minimize systemic effects.

DRUGS:epinephrine, ephedrine, isoproterenol, albuterol, terbutaline

The target is the smooth muscle of the bronchiole system: the drugs will cause relaxation of the muscle fibers and bronchodilation. Air movement into and out of the alveoli (through the bronchioles) is increased

Front 14

What are the clinical uses of sympathomimetics targeting the eye?

Back 14

The target is the muscle fibers of the iris dilator muscle: activation of receptors on these fibers produces pupillary dilation necessary for examination of the retina. The drugs are applied to the corneal surface of the eye to maximize exposure of the target cells to the drug and at the same time reducing drug effects on any other cells, tissues and organs.

DRUGS:
phenylephrine, epinephrine

Front 15

What are the clinical uses of sympathomimetics targeting the central nervous system?

Back 15

CNS "Stimulation"
Elevation of mood ("antidepressant" effect)
Treatment of narcolepsy - in which the affected individual frequently simply "falls asleep" at inappropriate times.
Appetite suppression - to decrease food intake and thus induce weight loss
Attention Deficit Disorder - in which the individual is unable to "concentrate on the job at hand"
phenylpropanolamine (ppa), methylphenidate (RITALIN)

Front 16

What are the clinical uses of sympathomimetics targeting the uterus?

Back 16

Drug is administered by injection to reduce uterine contractions in pregnant women when labor initiates prematurely. The problem with this treatment is that the drugs also cause decreased blood pressure, as a result of dilation of arterioles of skeletal muscle and heart, which by reflex is corrected by increased heart rate (tachycardia) with potential for palpitations and arrhythmias.

DRUGS: albuterol, terbutaline

Front 17

Toxicity and Side Effects of Sympathomimetics

Back 17

All of the "toxic" or side effects of sympathomimetics are essentially extensions of pharmacological, therapeutic actions of the drugs

Cardiovascular

Increased blood pressure

Tachycardia

Arrhythmias

Induction of Myocardial Infarction