Adrenergic Drugs Flashcards
Norepinephrine
@ *Alpha
e.g. Levophed: no longer used; was used to treat shock by Vasoconstriction, but also Constricted Renal Vessels, causing Renal Failure by Kidney Shock.
\_\_\_\_\_\_\_\_\_\_\_ Norepinephrine: Alpha mostly 1) Peripheral Vasoconstriction => Increases Peripheral Resistance => Increases Blood Pressure => Increases MAP (Mean Arterial Pressure) 2) Results in Reflex Bradycardia (Baroreflex)
Epinephrine
@ *Alpha, *Beta-1, *Beta-2
1) DOC: *Acute Hypersensitivity Reactions
(e.g. *Anaphylactic Shock)
Via injection primarily.
(Beta1: Stimulate Heart,
Beta2: Bronchodilation,
Alpha1: Vasoconstriction to Elevate Blood Pressure)
(Note: High Doses of Epi, or Epi given to a Hypotensive person will cause greater Alpha
2) *Heart Block and Cardiac Arrest (Emergency Use)
3) *Vasoconstrictor in *Local Anesthetic Preps
(e.g. Novocaine)
(Alpha1 Vasoconstriction)
(Keeps the anesthetic localized for longer, preventing systemic toxicity)
\_\_\_\_\_\_\_\_\_\_\_\_ Epinephrine: 1) Beta-2 Vasodilation (Skeletal muscle bed is large vascular bed) => Decreases Peripheral Resistance => Decreases Diastolic BP 2) Beta-1 Cardiac Stimulation => Increases Cardiac Output => Increases Heart Rate => Increases Systolic BP 3) Overall No change in MAP (Mean Arterial Pressure)
Dopamine
(precursor of NE and Epi)
@ Alpha-1, Beta-1, DA
*Important Drug for Shock:
_Maintains Renal Blood Flow!
_While Stimulating Heart and Vasoconstriction.
(DA treats shock while protecting Kidney;
NE treats shock while shocking Kidney.)
(D1 Receptor: Renal Arterial Dilation)
Isoproterenol
@ *All Beta Receptors
(Non-selective Beta Agonist)
_Used to be used to treat Asthma via Bronchodilation, but had Adverse Effects: Stimulation of Heart: Arrhythmias and Heart Attacks at young age.
(It has helped us Distinguish Alpha from Beta Receptors.)
__________
Isoproterenol: 1) Beta-2 Vasodilation (particularly @ Skeletal muscle bed, which is a very large vascular bed) => Decreases Peripheral Resistance (Markedly) => Decreases Diastolic BP => Decreases MAP (Mean Arterial Pressure) 2) Beta-1 Cardiac Stimulation => Increases Cardiac Output => Increases Heart Rate => Initial Increase in Systolic BP (transient) 3) => Overall Decreases in BP
Albuterol
Direct-Acting Sympathomimetics
Beta-2 Agonists
- *Major Drugs in Class:
1) *Albuterol (Ventolin)
2) *Salmeterol (Serevent, in Advair),
3) *Ritodrine (Yutopar)
Therapeutics:
1) Asthma (Bronchodilation)
2) Premature Labor
(Uterine Relaxation)
Adverse Effects: 1) *Tremors (*Beta-2 @ Skeletal Muscle) 2) *Cardiac Stimulation (*Beta-1)
Salmeterol
Direct-Acting Sympathomimetics
Beta-2 Agonists
- *Major Drugs in Class:
1) *Albuterol (Ventolin)
2) *Salmeterol (Serevent, in Advair),
3) *Ritodrine (Yutopar)
Therapeutics:
1) Asthma (Bronchodilation)
2) Premature Labor
(Uterine Relaxation)
Adverse Effects: 1) *Tremors (*Beta-2 @ Skeletal Muscle) 2) *Cardiac Stimulation (*Beta-1)
Ritodrine
Direct-Acting Sympathomimetics
Beta-2 Agonists
- *Major Drugs in Class:
1) *Albuterol (Ventolin)
2) *Salmeterol (Serevent, in Advair),
3) *Ritodrine (Yutopar)
Therapeutics:
1) Asthma (Bronchodilation)
2) Premature Labor
(Uterine Relaxation)
Adverse Effects: 1) *Tremors (*Beta-2 @ Skeletal Muscle) 2) *Cardiac Stimulation (*Beta-1)
Dobutamine
Direct-Acting Sympathomimetics
Beta-1 Agonist
Dobutamine (Prototype Drug)
Therapeutics:
1) *Cardiovascular Effects
2) Cardiac Decompensation,
* Acute CHF (Beta-1, Alpha-1)
Adverse Effect (Same Mechs):
1) *Arrhythmia (Beta-1)
2) *Hypertension (Alpha-1)
Mirabegron (Myrbetriq)
Direct-Acting Sympathomimetics
Beta-3 Agonist
Option if Muscarinic Blockers don’t work or can’t tolerate side effects.
Use:
1) Treat Overactive Bladder
(Beta-3: Relaxes Smooth Muscle @ Bladder)
Adverse Effects:
1) Mild Cardiovascular Stimulation (Beta-1)
Most Beta-3 mediate Metabolic effects: Lipolysis @ Adipose tissue
Phenylephrine
Direct-Acting Sympathomimetics
Alpha-1 Agonists
1) *Phenylephrine (NeoSynephrine)
2) *Oxymetazoline (Afrin)
3) *Pseudoephedrine (Sudafed)
Therapeutics:
1) *Nasal Decongestant
2) *Pressor (Increase BP)
Adverse Effects:
1) *Hypertension with *Reflex Bradycardia
(Reflex via baroreceptors in Carotid Sinus and Aortic Arch)
2) *Rebound Congestion
(rhinitis medicamentosa)
3) *Urinary Retention
(Urinary Sphincter Contraction)
(esp. Middle-aged/Older Males or if have enlarged prostate)
4) * CNS Stimulation:
e. g. *Insomnia
(Vasoconstriction in Nasal Mucosa, decreasing blood flow, which decreases leakage of fluids into tissues)
Oxymetazoline
Direct-Acting Sympathomimetics
Alpha-1 Agonists
1) *Phenylephrine (NeoSynephrine)
2) *Oxymetazoline (Afrin)
3) *Pseudoephedrine (Sudafed)
Therapeutics:
1) *Nasal Decongestant
2) *Pressor (Increase BP)
Adverse Effects:
1) *Hypertension with *Reflex Bradycardia
(Reflex via baroreceptors in Carotid Sinus and Aortic Arch)
2) *Rebound Congestion
(rhinitis medicamentosa)
3) *Urinary Retention
(Urinary Sphincter Contraction)
(esp. Middle-aged/Older Males or if have enlarged prostate)
4) * CNS Stimulation:
e. g. *Insomnia
(Vasoconstriction in Nasal Mucosa, decreasing blood flow, which decreases leakage of fluids into tissues)
Pseudoephedrine
Direct-Acting Sympathomimetics
Alpha-1 Agonists
1) *Phenylephrine (NeoSynephrine)
2) *Oxymetazoline (Afrin)
3) *Pseudoephedrine (Sudafed)
Therapeutics:
1) *Nasal Decongestant
2) *Pressor (Increase BP)
Adverse Effects:
1) *Hypertension with *Reflex Bradycardia
(Reflex via baroreceptors in Carotid Sinus and Aortic Arch)
2) *Rebound Congestion
(rhinitis medicamentosa)
3) *Urinary Retention
(Urinary Sphincter Contraction)
(esp. Middle-aged/Older Males or if have enlarged prostate)
4) * CNS Stimulation:
e. g. *Insomnia
(Vasoconstriction in Nasal Mucosa, decreasing blood flow, which decreases leakage of fluids into tissues)
Clonidine
Direct-Acting Sympathomimetics
Alpha-2 Agonists
1) *Clonidine (Catapres)
2) *Tizanidine (Zanaflex)
3) *Alpha-methyldopa
Therapeutics:
1) *Hypertension
(Acts centrally in Medulla of Brainstem to inhibit Sympathetics there)
2) *Glaucoma
(Reduces Formation of Aqueous humor, reducing intraocular pressure)
3) *Spasticity due to Neuropathy
(e.g. Cerebral Palsy)
(Acts in Spinal cord to reduce firing to motor neurons there)
4) *ADHD
(Not first-line. Aren’t as effective as Central Stimulants.)
Adverse Effects:
1) *Sedation
2) *Muscle Weakness
3) **Rebound Hypertension
4) Inability to Ejaculate
Tizanidine
Direct-Acting Sympathomimetics
Alpha-2 Agonists
1) *Clonidine (Catapres)
2) *Tizanidine (Zanaflex)
Therapeutics:
1) *Hypertension
(Acts centrally in Medulla of Brainstem to inhibit Sympathetics there)
2) *Glaucoma
(Reduces Formation of Aqueous humor, reducing intraocular pressure)
3) *Spasticity due to Neuropathy
(e.g. Cerebral Palsy)
(Acts in Spinal cord to reduce firing to motor neurons there)
4) *ADHD
(Not first-line. Aren’t as effective as Central Stimulants.)
Adverse Effects:
1) *Sedation
2) *Muscle Weakness
3) **Rebound Hypertension
4) Inability to Ejaculate
Amphetamine,
Methamphetamine
Indirect-Acting Sympathomimetics
Stimulate Release
- Amphetamine,
- Methamphetamine (Greater CNS Activity)
Therapeutics:
1) *Narcolepsy
2) *ADHD
Adverse Effects:
1) *Cardiovascular: Hypertension, Tachycardia
2) *Tremor
3) *Convulsions
4) *Dependence (chronic use)
5) *Psychosis (chronic use)
Tolerance Development: Tachyphylaxis
Note:
***Interaction of These with MAO Inhibitors can cause Hypertensive Crisis!!!
*Tolerance Development: Tachyphylaxis
= Rapid Tolerance with Repeated administration of drug
_Due to Depletion of NE and Rapid Desensitivity of the Receptors on the postsynaptic/effector cell.
