Flashcards in pharm cards Deck (140):
List the 4 most important pharmacokinetics equations: (Vd, Cl, LD, MD)
1) Vd = (amount of drug given)/([drug] in plasma)2) Cl = (Vd X 0.7)/t1/23) LD = Css X Vd4) MD = Css X Cl
competitive vs noncompetitive inhibitors:1) Resemble substrate?2) Overcome by increased [S]?3) Bind active site?4) Effect on Vmax?5) Effect on Km?6) Pharmacodynamics: effect on potency? efficacy?
Competitive inhibitors:1) Yes2) Yes3) Yes4) Vmax does not change5) Km increases6) decreased potency (increased Km, decreased potency); no effect on efficacyNoncompetitive inhibitors:1) No2) No3) No4) Vmax decreases5) Km does not change6) decreased efficacy (decreased Vmax, decreased efficacy); no effect on potentcy
rate of elimination of drug is constant, regardless of the plasma concentration; Cp decreases linearly with time.Examples = PEA: Phenytoin, Ethanol, Aspirin
Rate of elimination is proportional to drug concentration (a constant fraction of the drug is eliminated per unit time); the plasma concentration decreases exponentially with time.
Phase I vs Phase 2 metabolism:Which phase do geriatric patients lose first?
Phase I: -reduction, oxydation, hydrolysis-usually yields slightly polar, water-soluble metabolites (often still active)-cytochrome P-450Phase II:-GAS: Glucuronidation, Acetylation, Sulfation-usually yields very polar, inactive metabolites (renally excreted)*Geriatric patients lose phase 1 first
Efficacy vs Potency
Efficacy: -proportional to Vmax (increase Vmax, increase efficacy)-maximal effect a drug can produce-high efficacy drugs: analgesics, antibiotics, antihistamines, decongestantsPotency:-inversely proportional to Km (increase Km, decrease potency)-amount of drug needed for a given effect-increased potency, increased affinity for receptor-highly potent drugs: chemo drugs, anti-hypertensive drugs, antilipid drugs
Pharmacodynamics: Effects of adding competitive antagonists, noncompetitive antagonists, and partial agonists to an agonist on pharmacodynamic curves:
1) Competitive antagonist + agonist --> shift curve to the right = decreased potency (increased Km); no change on efficacy2) Noncompetitive antagonist plus agonist: shift curve down = decreased efficacy (decreased Vmax); no effect on potency3) Partial agonist: acts at the same site as a full agonist, but with reduced maximal effect. Get decreased efficacy (decreased Vmax); potency is variable, can be either increased or decreased.
Therapeutic Index: What is it? What's the equation? Is it safer to have a higher or lower TI?*Examples of drugs with low TI?
TI = measurement of drug safetyTI = LD50/ED50 = median lethal dose/median effective dose("TILE")Safer drugs have higher TI valuesExamples of drugs with low TI (must monitor these patients!):-Phenobarbital-Lithium-Digoxin-Coumadin/Warfarin
Nicotinic vs Muscarinic ACh receptors
Nicotininc ACh receptors = Na+/K+ channelsMuscarinic ACh receptors = G-protein-coupled receptors, act through 2nd messengers; 5 subtypes = M1, M2, M3, M4, M5
Gq:-what receptors stimulate it?-what are its effects?
-Stimulated by alpha 1, M1, M3, H1, V1-stimulates phospholipase C, which stimulates lipid conversion to PIP2, which stimulates increased diacylglycerol and increased inositol triphosphate. --> increased DAG leads to increased protein kinase C--> increased
Gs:-what receptors stimulate it?-what are its effects?
-stimulated by: B1, B2, D1, H2, V2-stimulates adenylyl cyclases --> increases cAMP --> increases protein kinase A --> increased intracellular Calcium *lots of bacterial toxins use this mechanism!
Gi:-what receptors stimulate it?-what are its effects?
-stimulated by: alpha 2, M2, D2-inhibits adenylyl cyclase (so decreased cAMP and decreased protein kinase A)...
alpha 1 receptor:-which G-protein class?-Major functions?
*Gq*Functions:-increase vascular smooth muscle contraction (increase BP)-mydriasis-increase intestinal and bladder sphincter muscle contraction
alpha 2 receptor:-G-protein class?-major functions?
*Gi*Major functions:-decrease sympathetic outflow (decrease NE secretion)-decrease insulin release-decrease BP (vasodilation)-increase glucagon secretion from alpha cells in pancreas
Beta 1 receptor:-G-protein class?-Major functions?
*Gs*Functions:-increase HR-increase contractility-increase renin release-increase lipolysis
Beta 2 receptor:-G-protein class?-Major functions?
*Gs*Functions:-vasodilation-bronchodilation-increase HR (compensatory to increase BP)-increase contractility-increase lipolysis-increase insulin release-decrease uterine tone
M1 receptor:-G protein?-Functions?
*Gq*Functions:-CNS, enteric nervous system
*Gi*Functions:-decreased HR and contractility of atria
M3 receptor: -G-protein?-Functions?
*Gq*Functions:-increase exocrine gland secretions (ie sweat, gastric acid)-increase gut peristalsis-increase bladder contraction-bronchoconstriction-increase miosis-accommodation (ciliary muscle contraction)
*Gs*Functions:-relaxes renal vascular smooth muscle
D2 receptor:-G protein?-Functions?
*Gi*Functions:-modulates transmitter release, especially in brain
H1 receptor:-G protein?-Functions?
*Gq*Functions:-increase nasal and bronchial mucus production-bronchiole contraction-pruritus-pain
H2 receptor:-G protein?-Functions?
*Gs*Functions:-increase gastric acid secretion
V1 receptor:-G protein?-Functions?
*Gq*Functions:-increase vascular SM contraction
V2 receptor:-G protein?-Functions?
*Gs*Functions:-increase H20 permeability and reabsorption in the collecting tubules of the kidney("V2 is found in the 2 kidneys")
What class of drugs are these:Bethanochol, Carbachol, Pilocarpine, Methacholine?
Cholinomimetic agents: Direct agonists
What class of drugs are these:Neostigmine, Pyridostigmine, Edrophonium, Physostigmine, Echothiophate, Donepezil
Cholinomimetic agents: Indirect agonists = anti-cholinesterases
What class of drugs are these:Atropine, homatropine, tropicamide, benztropine, scopolamine, ipratropium, oxybutynin, glycopyrrolate, methscopolamine, pirenzepine, propantheline
muscarinic antagonists = cholinergic antagonists
List the direct agonists/cholinomimetic agents (X4):
List the indirect agonists/cholinomimetic agents = anticholinesterases (X6)
List the muscarinic antagonists;
Cholinesterase inhibitor poisoning symptoms (ie excess parasympathetic activity): Antidote to anti-AchE poisoning?
Parathion = insecticide = organophosphate; causes cholinesterase-inhibitor poisoning (DUMBBELSS)
When do you give atropine + pralidoxime?
Give as an antidote to organophosphate poisoning/ Cholinesterase-inhibitor poisoning
Atropine:-class of drug?-clinical uses?-effects on eyes, airway, stomach, gi, bladder?-toxicity?
atropine = muscarinic antagonist*used to treat bradycardia and for ophthalmic applications*effects: blocks DUMBBELSS!-Eye--> increases mydriasis, cycloplegia-Airway-->decreases secretions-stomach --> decreases acid secretions-GI --> decreases motility-bladder --> decreases urgency in cystitis*Toxicity: Hot as a hare, Dry as a bone, Red as a beet, Blind as a bat, Mad as a hatter, Bloated as a toad:-increased body temp, decreased sweating-rapid pulse-dry mouth; dry/flushed skin-cycloplegia (blurry, near vision)-constipation (and urinary retention in men with prostatic hyperplasia)-disorientation-acute angle-closure glaucoma in elderly-hyperthermia in infants
What sympathomimetic should be used to treat:-anaphylactic shock?-cardiogenic shock?-septic shock?
Epinephrine:-type of drug-what receptors does it act on?-clinical applications
-direct sympathomimetic-acts on alpha 1, alpha 2, beta 1, beta 2-use for anaphylaxis, open angle glaucoma, asthma, hypotension (anaphylactic shock)
norepinephrine:-type of drug-what receptors does it act on?-applications
-direct sympathomimetic-acts on alpha 1, alpha 2, beta 1-use for hypotension (septic shock)
isoproterenol:-type of drug-what receptors does it act on?-applications
-direct sympathomimetic-acts equally on beta 1 and beta 2 receptors-used for AV block
dopamine:-type of drug-what receptors does it act on?-applications
-direct sympathomimetic-acts on all receptors, but its effects vary by dose:*low dose --> acts on D1*medium dose --> acts on B1 > B2*high dose --> acts on alpha 1 and alpha 2-used for shock (increases renal perfusion), heart failure
dobutamine:-type of drug-what receptors does it act on?-applications
-direct sympathomimetic-acts on Beta 1 mostly (also, slightly on alpha 1, alpha 2, beta 2)-used for heart failure, cardiac stress testing, cardiogenic shock
phenylephrine:-type of drug-what receptors does it act on?-applications
-direct sympathomimetic-acts on alpha 1 mostly (and a little on alpha 2)-used for pupillary dilation, vasoconstriction, nasal decongestion; good for stopping epistaxis
Metaproterenol, Albuterol, Salmeterol, Terbutaline:-types of drugs?-what receptors do they act on?-Applications
-direct sympathomimetics-B2-agonists (also act very slightly on B1)-Metaproterenol and Albuterol --> used for acute asthma-Salmeterol --> for long-term treatment of asthma-Terbutaline --> to reduce premature uterine contractions
Ritodrine:-type of drug-what receptors does it act on?-applications
-direct sympathomimetic-acts on B2 receptors ONLY!-used to reduce premature uterine contractions
List 3 indirect sympathomimetics:-What are their actions?-What are their clinical applications?
1) Amphetamines:-indirect general sympathetic agonist; release stored catecholamines-used for narcolepsy, obesity, ADD2) Ephedrine:-indirect general sympathetic agonist-release stored catecholamines-used for nasal decongestion, urinary incontinence, hypotension3) cocaine:-indirect general sympathetic agonist; uptake inhibitor-causes vasoconstriction and local anesthesia
clonidine and alpha-meythldopa:-type of drugs?-act on what type of receptor?-applications?
anti-fungal (ie ketoconazole)
penicillin (ie methicillin)
antibiotic, protein synthesis inhibitor (ie tetracycline)
protease inhibitor (HIV trtmt) (ie saquinavir)
5-HT1B/1D-agonists (for migraines) (ie sumatriptan)
inhalational general anesthetic (ie halothane)
butyrophenone (neuroleptic) (ie haloperidol)
phenothiazine (neuroleptic, antiemetic) (ie chlorpromazine)
barbiturate (ie phenobarbital)
benzodiazepine (ie alprazolam)
benzodiazepine (ie diazepam)
SSRI (ie fluoxetine)
TCA (ie imipramine)
TCA (ie amitriptyline)
beta-antagonist (ie propranolol)
beta2-agonist (ie albuterol)
alpha 1-antagonist (ie prazosin)
cardiac glycoside (inotropic agent) (ie digoxin)
ACE-inhibitor (ie captopril)
erectile dysfunction (ie sildenafil)
pituitary hormone (ie somatotropin)
H2-antagonist (ie cimetidine)
bisphosphonate (for osteoporosis) (ie alendronate)
Ang II-receptor-antagonist (ie losartan, valsartan)
cholinergic/muscarinic agonist (ie bethanechol, carbachol)
-curium or -curonium =
paralytic drugs (non-depolarizing NM-blocking drugs; reversed with neostigmine) (ie atracurium, vecuronium)
anti-cholinesterase (ie neostigmine, physostigmine, pyridostigmine)
nitrosureas (cross BBB, used to treat brain cancers)
HMG-coA reductase inhibitors (ie atorvastatin)
increase target cell response to insulin (ie rosiglitazone, pioglitazone)
anti-parasitic (esp anti-helminthic)
Ca-channel blockers (specifically dihyropyridine CCB's) (ie nifedipine, amlodipine)
prostaglandin analogues (treat glaucoma) (ie unoprostone)
monoclonal antibody (ie infliximab, daclizumab)
alpha 1 blockage leads to?alpha 2 blockage leads to?
alpha1-blockage --> vasodilationalpha2-blockage --> vasoconstriction
phenoxybenzamine:-type of drug?-application?-toxicity?
-nonselective alpha-blocker (irreversible/non-competitive)-used for pheochromocytoma (use phenoxybenzamine before removing tumor)-toxicity: orthostatic hypotension, reflex tachycardia
Phentolamine:-type of drug-application?
-nonselective alpha-blocker (reversible/competitive)-give to patients on MAO-inhibitors who eat tyramine-containing foods
prazosin, terazosin, doxazosin:-types of drugs?-applications?-toxicity?
-alpha-1-selective-blockers-used for hypertension, urinary retention in BPH-toxicities: orthostatic hypotension with first dose; dizziness, headache (should give pts first dose before bed, while lying down)
mirtazapine:-type of drug-application-toxicity
List the B1-selective antagonists (A BEAM):
Acebutolol (partial agonist)BetaxololEsmolol (short-acting)AtenololMetoprolol
List the nonselective Beta-antagonists (Please Try Not being Picky)
List the partial beta-agonists (PAPA):
Nonselective alpha and beta -antagonists:
Clinical applications of beta-blockers:
-hypertension (decrease CO, decrease renin secrtion - by beta-receptor blockade on JGA cells)-angina pectoris (decrease HR and contractility, so have decreased O2 consumption of myocardium)-MI (metoprolol and carvedilol --> decrease mortality from MIs)-SV
Toxicity of Beta-blockers
-impotence!-exacerbates asthma-CV adverse effects (bradycardia, AV block, CHF)-CNS adverse effects (sedation, sleep alterations)-use caustiously with diabetics! (b/c B-blockers block sympathetically-mediated symptoms of hypoglycemia; so, patient won't be
Bethanecol = direct cholinomimetic-used for postoperative and neurogenic ileus and urinary retention (activates Bowel and Bladder)
carbachol = direct cholinomimetic-used for glaucoma, pupillary contraction, relief of intraocular pressure
-pilocarpine = direct cholinomimetic-used to stimulate sweat, tears, saliva ("cry, spit, sweat on your pillow")
Which cholinomimetics are resistant to AChE?
methacholine = direct cholinomimetic-used as a challenge test to diagnose asthma
neostigmine - anticholinesterase (indirect cholinomimetic)-used for postoperative and neurogenic ileus and urinary retention, myasthenia gravis, reversal of NM jxn blockade-increases endogenous ACh; does not penetrate the CNS
pyridostigmine = anticholinesterase (indirect cholinomimetic)-used for myasthenia gravis (gets RID of MG)-does not penterate CNS-increases endogenous ACh
endrophonium = anticholinesterase (indirect cholinomimetic)-used to diagnose myasthenia gravis-increases endogenous Ach
physostigmine = anticholinesterase (indirect cholinomimetic)-used to treat glaucoma and atropine overdose ("phyxes" atropine OD)-crosses the BBB!-increases endogenous Ach
echothiphate = anticholinesterase (indirect cholinomimetic)-used to treat glaucoma-increases endogenous Ach
donepezil = anticholinesterase (indirect cholinomimetic)-used to treat Alzheimer's disease-increases endogenous Ach!
pKa = acid dissociation constant = ?
pKa = pH at which amount of the non-protonated form = the amount of the protonated form
if pH < pKa...
acidic environment; have more of the protonated form (so, basic drugs get trapped)
if pH > pKa...
basic environment; have more of the nonprotonated form (acidic drugs get trapped)
Treat acidic drug OD (ie slicylates) with?
NaHCO3 (traps the acidic drug in the basic urine)
Treat basic drug OD (ie amphetamines) with?
NH4Cl (ammonium chloride; traps basic drug in the acidic urine)
What class of drugs can cause excess parasympathetic activity (ie DUMBBELSS symptoms)?
What drug regenerates AchE after organophosphate poisoning?
Pralidoxime (regenerates active AchE) (also, give atropine to treat symptoms!)
What are the symptoms of inhibiting parasympathetic activity?
(ie atropine side effects)Hot as a hareDry as a boneRed as a beetBlind as a batMad as a hatterBloated as a toad
In what populations is atropine contraindicated?
-Glaucoma (because don't want to dilate eyes)-BPH or any urinary retention-GI obstruction (ie ileus)-Dementia or Elderly (because can cause delirium)-Infant with fever (because can cause hyperthermia)-
List 4 classes of drugs with anti-cholinergic side effects:
1) First generation H1-Blockers (diphenhydramine, doxylamine, chlorpheniramine)2) Traditional neuroleptics3) TCAs4) Amantadine
List 4 treatment options for Myasthenia Gravis:
1) Anti-cholinesterases (indirect cholinergic agonists)2) Corticosteroids (because MG = autoimmune disease)3) Thymectomy (often curative)4) Plasmapheresis
What are the 5 classes of drugs used to treat glaucoma?
1) alpha-agonists2) beta-blockers3) Diuretics (Carbanic anhydrase inhibtors and mannitol)4) cholinomimetics5) prostaglandins
Barb Steals Phen-phen and Refuses Greasy Carbs Chronically:BarbituratesSt. John's wortPhenytoinRifampinGriseofulvinCarbamazepineChronic alcohol use
Q-MAGIC RACKS:QuinidineMacrolidesAmiodaroneGrapefruit juiceIsoniazidCimetidineRitonavirAcute alcohol abuseCiprofloxacinKetoconazoleSulfonamides
acetaminophen antidote? (toxic dose = 4 g/day = 8 extra-strength tablets)
N-acetylcysteine (replenishes glutathione)
salicylates (ie aspirin) antidote?
NaHCO3 (alkalinizes urine)Dialysis
NH4Cl (acidifies urine)
anti-acetylcholinesterase and organophosphates antidote?
Atropine + Pralidoxime
antimuscarinic, anticholinergic agents (ie atropine) antidote?
(same as verapamil antidote!) = glucagon, calcium, atropine (all increase HR)
CaEDTA (in adults)Dimercaprolsuccimer (in kids)penicillamine
mercury, arsenic, gold antidote
-dimercaprol (BAL) (dimes = money = gold; merc = mercury!)-succimer
copper, arsenic, gold antidote
penicillamine (copper pennies!)
(may get cyanide poisoning from nitroprusside, used for malignant HTN; also, from house fires -- see CN toxicity along with CO poisoning)-nitrite-hydroxocobalamin-thiosulfate
Carbon monoxide antidote
100% O2Hyperbaric O2
NaHCO3 (plasma alkalinization)
protamine (H+ = Proton-amine!)
vitamin Kfresh frozen plasma
tPA, streptokinase, urokinase antidote?
Beta-blocker(theophylline is an option for COPD pts; it has a low TI with cardio-toxicity; so, give beta-blockers for the cardio-toxic effects)
same as beta-blocker antidote! = glucagon, calcium, atropine (all increase HR)
-Normalize K+ and Mg2+-lidocaine (if there's tachyarrhythmia) -anti-dig fab fragments (if there's arrhythmia)-atropine (if there's bradycardia)
-methylene blue-vitamin C