Sympathomimetics Flashcards
Name a typical nonselective alpha agonist
Phenylephrine (flannel friends)
Alpha 1 receptors are widely expressed in vascular beds in the nasal mucosa
Nasal spray containing phenylephrine is used as a decongestant, because of local vasoconstriction it reduces edema of the nasal mucosa
Also causes mydriasis (pupillary dilator muscle)
Also increases MAP mean arterial pressure (increases sys and dias p)
Norepinephrine has a higher affinity for
A. alpha
B. beta adrenergic receptor
A. alpha
Name selective B1 agonists
DOPAMINE in medium dose (2.5-5 microgram/kg/min)
DOBUTAMINE
- causes less tachycardia compared with dopamine
Indications: cardiogenic shock, acute heart failure?
Adverse effects: tachycardia
Name a nonselective Beta agonist
Isoproterenol
Name a selective beta2 agonist
Terbutaline (do not disTURB) - prevents premature labor, relaxes the uterus
These agents are also useful in bronchodilation
1) for acute bronchospasm : Albuterol, Metaproterenol, Terbutaline
2) prophylaxis of asthma : Salmeterol, Formoterol, Indacaterol
Name the slow onset, long acting B2 agonists used for prophylaxis of asthma or COPD
Salmeterol Formoterol Indacaterol Olodaterol Vilanterol
…are used in combination with corticosteroids or anti-muscarinic agents for prophylaxis in asthma or COPD
What are the drugs of choice in the treatment of acute asthmatic broncho-constriction?
Short-acting beta2 selective agonists
Albuterol
Metaproterenol
Terbutaline
(Inhale via aerosol canister)
What type of drug would be bad for someone with BPH (benign prostatic hyperplasia) ?
An alpha1 agonist!
Alpha 1 receptors are found in the prostatic urethra . They are Gq coupled so they lead to contraction -> urinalysis retention
Kaplan
Identify the drug below, that can specifically inhibit sympathetic induced Renin release.
A beta1 blocker !!!!
for example: atenolol
If you block beta2 receptors - what do you expect to happen to blood glucose levels?
Hypooooglycemia
Beta2 receptor activation on skeletal muscle and the liver leads to increased Glycogenolysis -> increased blood glucose levels
Name an Alpha2 agonist and its effect/ use as a drug.
(This card would rather belong to sympathoplegic drugs…)
CLONIDINE
used to treat hypertension
What is the drug of choice for the immediate treatment of anaphylactic shock (hypotension, bronchospasm, angioedema)
Epinephrine …because it is an effective physiologic antagonist of many of the mediators of anaphylaxis
What drugs are used in attention deficit hyperkinetic disorder (ADHD)?
Methylphenidate (and other amphetamine analogues)
These drugs are abused or misused for the purpose of deferring sleep and for their mood-elevating, euphoria-producing action
Why are alpha agonists often mixed with local anesthetics?
Alpha agonists, such as Epinephrine reduce the loss of anesthetic from the area of injection into circulation via vasoconstrictive properties
Name of drug that an be used to treat orthostatic hypotension (e.g in autonomic failure, a neurodegenerative disorder)
Midodrine (an alpha 1 agonist)
What are some possible side effects of Midrodrine (alpha 1 agonist)
Supine hypertension, piloerection (goose bumps), urinary retention
Name a drug that could be used if pupillary dilation - but not cycloplegia- is desired.
Phenylephrine
An alpha1 agonist (sympathomimetic)
You prescribe a highly selective beta2 agonist inhaler to be used when needed, to a patient with moderately severe asthma.
What is a possible side effect?
Skeletal muscle tremor
Tachycardia
Hyperglycemia
Hypokalemia
Norepinephrine indications
Neurogenic shock (early phase)
Septic shock
Cardiogenic shock
Name 3 indications for the use of Epinephrine
Anaphylactic shock (0.3-0.5 mg sc. or im.)
Emergency management of complete heart block and cardiac arrest (1mg iv.)
Inhaled epinephrine for treatment of croup (subglottic laryngitis)
Reduction of regional blood flow (in combination with local aneasthetics, or in facial nasopharyngeal and oral surgery)
Peripheral Dopamine receptor agonists (D1)
Dopamine - in LOW dose !
…dilates mesenteric and renal blood vessels
Fenoldopam
…peripheral vasodilation in mesenteric vascular bed
(administered i.v for treatment of severe hypertension
Dopexamin
…D,beta2,(beta1) agonist , (reuptake inhibitor)
Patients taking MAO-A inhibitors must avoid …?
Foods containing TYRAMINE ( cheese, wine, smoked fish)
If they don’t, tyramine reaches systemic circulation and increases the sympathetic tone by releasing norepinephrine-> hypertensive crisis !!
A 25 year old woman at 32 weeks gestation begins taking a drug to delay the onset of preterm labor.
What type of drug could be used?
A beta2 agonist (i.e Terbutaline)
CLONIDINE
Treats hypertension urgency
or ADHD or Tourette’s
CLONIDINE is a alpha2 agonist !!!
It’s a centrally acting sympatholytic
Decreases sympathetic tone