Drugs Flashcards
(27 cards)
Phenoxybenzamine
Irreversible alpha 1, alpha 2 anatagonist
- prevents vasoconstriction, decreases BP
- non selective, non competitive alpha antagonist
- irreversible, manages hypertension caused by pheochromocytoma: prior to the surgical removal of the tumor. For chronic management of inoperable tumors.
Clonidine
Alpha 2 agonist
Treatment for hypertension and opioid withdrawal
side effects: Bradycardia and hypotension
Phentolamine
alpha 1, alpha 2 antagonist-prevents vasoconstriction
Reversible, competitive antagonist
Control of HTN during properative preparation and surgical excision
prevention of dermal necrosis after extravasation of norepinephrine
hypertensive control of stimlant drug effect
manages hypertension caused by pheochromocytoma
Pancuronium
Neuromuscular Nicotinic Antagonist
(Non-depolarizing (competitive) neuromuscular blocker
-induction of muscle paralysis (flaccid) in surgery
Side effecs: Hypertension, apnea, bronchospasm, salivation, flushing and respiratory failure.
Atenolol
Selective B1 blocker
- Treats hypertension and angina, reduces blood volume via decrease in renin production
- Side effects: sedation and dyspnea
Pindolol
Partial agonist beta 1
-treats hypertension in patients with bradycardia or low cardiac reserve
Propranolol
Non-selective Beta blocker
-treatment for hypertension and angina
side effects: More severe sedation, bronchoconstriction and dyspnea
Neostigmine and Physostigmine
Reversible anticholinesterase
- Longer duration of action; useful for treatment of Myasthenia Gravis
- treatment for Atropine poisoning
- Physostigmine crosses BBB
Edrophomium
Reversible anticholinesterase
-short duration of action; useful for diagnosing Myasthenia Gravis (autoimmune disease against Nm subtype) and Lambert Eaton (autoimmune disease against Ca+2 channels-reduces ACh release)
Albuterol
B2 agonist
- avoids cardiac B1
- used as Asthma reliever. Rapid action (15mins) relative short duration (4-6hrs)
Dobutamine
B1 Agonist
- Prominent Ionotropic effects–>increased contractibility and cardiac output but not heart rate-no change in peripheral resistance.
- Short half life due to COMT metabolism
- used in acute management of heart failure (note more than just B1 activity)
Ephedrine and Pseudoephedrine
Inhibitors of Catecholamine Storage
Used for nasal decongestion-increase NE activity at post synaptic alpha and beta receptors.
Amphetamines
Inhibitors of Catecholamine storage
- displaces endogenous Catecholamine from vesicles
- blocks NET
- Weak inhibitor of MAO
Atropine
Muscarinic antagonist
-allows sympathetic responses to predominate
-competitive antagonist
-reverses sinus bradycardia caused by excessive vagal tone
Reduces: SLUDGE
Actions: Pupil dilation Tachycardia, decrease secretions (Salivary , bronchial, GIT)
Pilocarpine
Muscarinic agonist
- similar to muscarine
- until recently only MR agonist to be used clinically
- treats glaucoma, causes miosis, drains aquoes humor-decreases intraocular pressure
- used to treat dry mouth in sjorgens syndrome
Methacholine
Muscarinic Agonist
- 3x more resistant to hydrolysis by AChE
- little affinity for Nicotinic receptors
- used in diagnosis of asthma–>asthmatics are more sensitive to bronchial secreting actions of methacholine; will respond to lower doses than a normal individual
Bethanecol
Muscarinic agonist
- almost completely selective for muscarinic receptors
- agent choice for promoting GI and urinary tract motility; assists in bladder emptying
- particularly post-operative, post-partum and drug-related urine retention
Botulinum toxin (Botox)
Prevents ACh release.
- degrades synaptobrevin (vSNARE) and prevents vesicle fusion/exocytosis
- Used clinically to paralyze selected muscles with excessive tone; focal dystonia and for unmasking subclinical Lambert Eaton Syndrome
Oxymetazoline
Alpha 1, Alpha2 agonist
-Topical/nasal decongestant (Vicks, Sudafed, Afrin, Dristan); treats ocular hyperemia-eye redness (Visine)
epinephrine (high at adrena medulla) and Norepinephrine (high at sympathetic nerve fibers)
alpha and beta agonists
EPI: higher affinity for B2 - predominant Beta effect; at higher concs has effects on alpha 1; higher doses effective at treating anaphylaxis and used for vasoconstriction in conjunction with local anesthetic
NOR:affinity for alpha1 and Beta1; little affinity for Beta2
- Epi slightly more potent at alpa 1
- both equipotent at B1
Succinylcholine
Neuromuscular Nicotinic agonists (depolarizing Neuromuscular Blocker)
- keeps muscles from contracting
- desensitization of Nm receptor leading to muscle paralysis
- Paralysis of pharyngeal muscle for intubation and ventilation
- Ach worsens because of desensitization
Prazosin and Tamsulosin
alpha 1 antagonist
- long half life
-treatment for hypertension and benign prostatic hyperplasia
Prazosin side effects: postural orthostatic/hypotension related to first dose phenomena
Tamsulosin: selective for genitourinary smooth muscle receptor subtype (a1A)
-side effects: less postural/ orthostatic hypotension
- BPH use tamsulosin better.
Phenylephrine
alpha 1 agonist
Nasal decongestant; treatment of shock
-Side effects: hypertension
-Used to increase BP in hypotension resulting from vasodilation in septic shock or anesthesia.
Malathion
Irreversible anticholinesterase
- toxic, used in pesticides
- death
