Pharm2 6 Neuro pt1 Flashcards
An action potential passing down an axon to the axon terminal changes the membrane potential resulting in ___ entry into the cell
This triggers the fusion of neuro-containing vesicles & cell membranes releasing neurochemical transmitters into the ____
Ca+2
synaptic cleft
What do Neurotransmitters (and the drugs that mimic them) do? (4)
block the uptake of neurotransmitters
block the re-uptake of neurotransmitters
enhance the release of neurotransmitters
enhance the uptake of neurotransmitters
as of yet, we cannot develop a drug that …
BLOCKS the RELEASE of of a neurotransmitter
4 primary neurotransmitters
Norepinephrine (NE)
Acetylcholine (Ach)
Dopamine
Serotonin
A Lot of Different Things Can Occur near the Synapse (7)
Stop nerve impulse transmission to synapse
Stop precursor or neurotransmitter (NT) synthesis
Bind to or inactivate NT in cleft
Block NT post-synaptic receptor attachment
Inhibit re-release of precursor or NT
Inhibit reabsorption of precursor or NT
Inhibit re-synthesis of NT
Autonomic drugs are classified by
which receptor they act upon and either stimulate or block
4 types of Autonomic drugs (and what they do)
Sympathomimetics (adrenergic-agonists) stimulate the sympathetic nervous system (fight or flight)
Parasympathomimetics (cholinergic-agonists) produce the R&R response
Adrenergic-blockers inhibit sympathetic nervous system producing actions opposite to sympathomimetics
Anti-cholinergics (cholinergic-blockers) inhibit parasympathetic nervous system producing actions opposite to parasympathomemetics
Muscarinic Receptors
What’s the NT, Primary locations, Responses
Acetylcholine (cholinergic)
Parasympathetic target; organs other than the heart
Stimulation of smooth muscle; gland secretions
Nicotinic Receptors
What’s the NT, Primary locations, Responses
Acetylcholine (cholinergic)
Postganglionic neurons, skeletal muscle, neuromuscular junction
Stimulation of smooth muscle, gland secretions
Alpha1 Receptor
What’s the NT, Primary locations, Responses
Norepinephrine (adrenergic)
All sympathetic target organs except the heart
Constrict blood vessels, dilate pupils
Alpha2 Receptor
What’s the NT, Primary locations, Responses
Norepinephrine (adrenergic)
Pre-symaptic adrenergic nerve terminals
Inhibit release of norepinephrine
Beta1 Receptor
What’s the NT, Primary locations, Responses
Norepinephrine (adrenergic)
Heart & kidneys
Increase HR, force of contraction; Renin release
Beta2 Receptor
What’s the NT, Primary locations, Responses
Norepinephrine (adrenergic)
All sympathetic target organs except the heart
Inhibition of smooth muscle
What is the prototypical parasympathomimetic?
bethanechol
Prototypical Parasympathomimetic: bethanechol (Urecholine®)
Indication, MoA
Indications: Urinary retention
Mechanism of action: Direct acting parasympathomimetic, intefering with Ach receptors resulting in smooth muscle contraction, stimulating urinary & GI tracts
bethanechol (Urecholine®)
Adverse fx, CI
Adverse Effects: abdominal cramping, N&V, increased salivation, sweating, hypotension, syncope
Contraindications: Allergy, asthma, CAD, obstructive uropathy, bradycardia, BPH, hypotension, epilepsy, Parkinson’s, peptic ulcer, inflammatory GI disorders
What is the prototypical Anticholinergic?
Atropine sulfate
Atropine Sulfate (Atropine) Indications Mechanism of action
Indications: Bradycardia, facilitate ophthalmological exams, pre-anesthesia
Mechanism of action: Blocks Ach (muscarinic) receptors, induces symptoms of fight or flight, including increases heart rate, bronchodilation, decreases GI motility, mydriasis (pupilary dilation)
Atropine Sulfate (Atropine)
Adverse Effects
Contraindications
Adverse Effects: Tachycardia, palpitations, constipation and GI obstruction, may precipitate acute narrow angle glaucoma
Contraindications: Allergy, tachycardia, arrhythmias, CAD, history of bowel obstruction, history of glaucoma
What is the prototypical Sympathomimetic?
Albuterol Sulfate
Albuterol Sulfate (Proventil®) Indications Mechanism of action
Indications: Asthma, bronchospasm, reactive airway disease,
Mechanism of action: Selected Beta2-agonist, resulting in bronchial smooth muscle relaxation
Albuterol Sulfate (Proventil®)
Adverse Effects
Contraindications
Adverse Effects: Tachycardia, tremor, headache, hyperactivity, paradoxical bronchospasm, avoid with MAOIs, antagonized by beta-blockers
Contraindications: Allergy, arrhythmias, severe CAD/HTN
What is the prototypical beta Adrenergic-Blocker?
Metoprolol
metoprolol (Lopressor®)
Indications
Mechanism of action
Indications: Hypertension, tachyarrhythmias, AMI mortality reduction, AMI prophylaxis, angina prophylaxis
Mechanism of action: Inhibit the sympathetic nervous system, specifically by blocking beta-1 receptors primarily in the heart
metoprolol (Lopressor®)
Adverse Effects
Contraindications
Adverse Effects: Bradycardia, bronchospasm, fatigue, dizziness, depression, anhedonia, impotence
Contraindications: Severe bradycardia, 2nd/3rd degree heart block, overt CHF, cardiogenic shock, bronchospastic disease
What is the prototypical alpha Adrenergic blocker?
Doxazocin
Doxazocin (Cardura®)
Indications
Mechanism of action
Indications: Hypertension, BPH
Mechanism of action: Inhibit the sympathetic nervous system, specifically by selectively blocking alpha1 receptors primarily in vascular smooth muscle, dilating both arteries and veins as well as relaxing smooth muscle surrounding the prostate
Doxazocin (Cardura®)
Adverse Effects
Contraindications
Adverse Effects: Syncope, dizziness, orthostatic hypotension, esp. with first does and increasing doses
Contraindications: Allergy, hypotension,
How do SSRI’s work?
Calcium fires to the end of a synapse, and NT in the synapse containing serotonin. The next nerve signals to send more Ca++
Why does Bethenechol worsen asthma?
Because of all the secretion of fluids (in mouth, lungs)
Why is CAD a contraindication for Bethanechol?
b/c they’ll be hypotensive and have coronary ischemia
What is obstructive uropathy (a CI for Bethanechol)
a kidney stone in their urethra
Why would you give Atropine in IV form? (2)
bradycardiia
tiny dose to dry up your mouth prior to anesthesia so you’re not choking on your own secretions.
Give a tiny dose of what to prevent a patient from choking on their own secretions while they are under anesthesia
Atropine sulfate
What is used to stop premature labor?
Albuterol sulfate
