Pharmacology Chapter 18: Adrenergic Drugs

Study Notes

Dopamine

Brand name: Intropin
Class: Beta 1 adrenergic
Indications: Used for shock, pulmonary arrest, and to increase blood pressure (BP)
Action: Stimulates B1 adrenergic receptors in the heart, enhancing force of contraction, heart rate (HR), conduction, and increases renin production in kidneys
Route: Administered intravenously (IV)
Adverse reactions: Possible dysrhythmias, tremors, and fluctuations in BP
Nursing implications: Regularly assess cardiac and respiratory function, monitor urine output, and EKG readings
Therapeutic outcome: Aims for improved cardiac output, normalized BP, and enhanced capillary flow

Midodrine

Brand name: ProAmatine
Class: Alpha 1 adrenergic
Indications: Treats orthostatic hypotension and supports cardiovascular system during failure or shock
Action: Alpha1 stimulation causes vasoconstriction in arterioles and veins, leading to increased peripheral resistance
Route: Administered orally at 10mg three times a day (TID)
Adverse reactions: Risks include bradycardia, supine hypertension, and headaches
Nursing implications: Monitor orthostatic blood pressure and renal/hepatic function; first dose should be taken shortly after waking
Therapeutic outcome: Aims to decrease symptoms of orthostatic hypotension and urinary incontinence

Epinephrine

Brand: Adrenalin
Class: Beta/Alpha adrenergic
Indications: Used in cases of anaphylaxis, cardiac stimulation, and emergency cardiac life support
Action: Relaxes bronchiole smooth muscle via stimulation of beta 2 and alpha receptors in the sympathetic nervous system; increases force of contraction and HR
Route: Can be given IV or intramuscularly (IM)
Adverse reactions: Possible drowsiness, palpitations, and dyspnea
Nursing implications: Monitor lung sounds, respiratory patterns, check for chest pain, and EKG changes; may cause increased glucose levels in diabetes patients
Therapeutic outcomes: Aims to elevate BP when used as a vasopressor, improve ease of breathing, and reverse anaphylaxis symptoms

Phenylephrine

Brand: Neo-Synephrine
Class: Alpha adrenergic
Indications: Raises BP in shock patients, controls dysrhythmias, and produces vasoconstriction
Action: Stimulates alpha adrenergic receptors to constrict blood vessels
Route: Administered intravenously (IV)
Adverse reactions: Potential BP elevation, dizziness, and arrhythmias
Nursing implications: Monitor BP every 2-3 minutes until stable; must dilute the IV solution
Therapeutic outcome: Aims to increase BP to normal ranges

Positive Inotropic Effect

Definition: Refers to the increased force of contraction of the heart

Positive Chronotropic Effect

Definition: Refers to the increased heart rate

Positive Dromotropic Effect

Definition: Refers to increased conduction through the AV node, leading to a stronger systolic heartbeat

Adrenergic Drugs

Stimulate the sympathetic nervous system (SNS)
Also called sympathomimetics because they mimic effects of SNS neurotransmitters: norepinephrine, epinephrine, and dopamine

Catecholamines

Definition: Substances that induce a sympathomimetic response, primarily epinephrine, norepinephrine, and dopamine, triggering the fight or flight response

Alpha 1 Receptors

Location: Found on postsynaptic effector cells such as muscle, organ, or cell that is stimulated by the nerve

Description

Explore key concepts related to adrenergic drugs with this flashcard quiz. Learn about dopamine, its indications, mechanisms of action, and nursing implications. Perfect for students studying pharmacology or nursing.