Pharm (A/Q) Flashcards
Measures the affinity of an enzyme for its substrate ( dec Km = inc affinity)
Km
Maximal velocity of an enzymatic reaction (proportional to enzyme concentration)
Vmax
Does not change Vmax (Lineweaver-Burke lines cross each other “competitively”)
Competitive inhibition
Decreases Vmax (Lineweaver-Burke lines do not cross each other)
Noncompetitive inhibition
Drug in body / plasma drug concentration (low Vd (4-8L: in blood)’ medium Vd (in extracellular space)’ High Vd (> body weight: in tissues))
Volume of Distribution (Vd)
Rate of elimination of drug / plasma drug concentration (OR Vd x Kc’ where Kc is the elimination constant)
Clearance (CL)
T1/2 = (0.7 x Vd) / CL
Half life (t1/2)
1:50%’ 2:75%’ 3:87.5%’ 4:93.75%
Concentration of a substance after X half lives (1’2’3’4)
”= Cp x (Vd / F); (Cp: target plasma conc., F: bioavailability, 1 if by IV)
Loading dose
”= Cp x (CL / F); (Cp: target plasma conc., F: bioavailability, 1 if by IV; a renal patient would have decreased clearance, so they would need a decreased maintenance dose)
Maintenance dose
PEA (phenytoin, ethanol, aspirin)
Common drugs that follow zero-order elimination
Will get trapped in a basic environment, treat with bicarbonate
Treating a weak acid overdose
Will get trapped in an acidic environment, treat with ammonium chloride
Treating a weak base overdose
(Cytochrome P450) 1. reduction, 2. oxidation, 3. hydrolysis (drugs became slightly polarized, may still be active)
Reactions involved in phase I drug metabolism
(Conjugation) 1. acetylation, 2. glucuronidation, 3. sulfonation (drugs become very polarized, are inactivated)
Reactions involved in phase II drug metabolism
Competitive antagonist shifts curve right, requires bigger dose of drug for effect (inc EC50); noncompetitive antagonist shortens curve, cannot reach same level of effect (dec efficacy)
Effect of competitive antagonists on efficacy curves versus noncompetitive antagonists
Partial agonists will have a lower maximal efficacy than full agonists (however potency is independent, they may still be more potent or less potent than a full agonist)
Effect of partial agonists versus full agnoists on efficacy curves
TILE: TI = LD50 / ED50 (median toxic dose / median effective dose; Safer drugs have HIGHER TI values)
Therapeutic index (TI)
Receptor location: NMJ; Function: skeletal muscle contraction; Mechanism: ion channel (Na influx)
Nm receptors
Receptor location: Ganglia; Function: stimulates sympathetics and parasympathetics; Mechanism: ion channel (Na influx);
Nn receptors
Receptor location: Nerve endings; Function: Gastric acid secretion; Mechanism: Gq protein;
M1 receptors
Receptor location: Heart; Function: Inhibitory, reduces heart rate; Mechanism: Gi protein;
M2 receptors
Receptor location: Smooth muscle, endothelium, glands; Function: bronchoconstriction, pupil constriction, accommodation, increases secretions; Mechanism: Gq proteins;
M3 receptors
Receptor location: Arterioles, glands; Function: vasoconstriction, pupillary dilation; Mechanism: Gq protein;
a1
Receptor location: presynaptic nerve endings; Function: inhibitory, feedback inhibition of NT release; Mechanism: Gi protein;
a2
Receptor location: heart, kidney; Function: heart stimulation, renin release; Mechanism: Gs protein;
b1
Receptor location: lungs, skeletal muscle; Function: Vasodilation, bronchiole dilation, ciliary process (makes aqueous humour); Mechanism: Gs protein;
b2
Receptor location: Fat; Function: excitatory; Mechanism: Gs protein;
b3
Function: vasodilation; Mechanism: Gs protein;
D1
Function: Causes NT release in brain; Mechanism: Gi protein;
D2
Function: stimulates mucuous production, bronchiole constriction, pain, itching; Mechanism: Gq protein;
H1
Function: gastric acid secretion; Mechanism: Gs protein;
H2
Function: vasoconstriction; Mechanism: Gq protein;
V1
Function: inc H20 permeability, reabsorption in collecting tubules in kidney; Mechanism: Gs protein;
V2
Sick of sex (SIQ, SQS) D1,D2, H1, H2, V1, V2
Mnemonic for g protein receptors used for D, H, and V receptors
Gq protein activates PLC, IP3 + DAG, inc Ca++ (IP3) and activate PKC (DAG)
Function of Gq protein receptors
Gi protein activates K+ channels, inhibition of adenylate cyclase, reduction of cAMP
Function of Gi protein receptors
Gs protein activates adenylate cyclase, increases cAMP
Function of Gs protein receptors
DUMBBELSS (Diarrhea, urination, miosis, bronchospasm, bradycardia, excitation (of skeletal muscle), lacrimation, sweating, salivation); treatment: atropine (reverses symptoms) + pralidoxime (regenerates cholinesterase)
Symptoms of cholinesterase inhibitor poisoning
Hot as a hare (inc temp), Dry as a bone (dec secretions), Red as a beet (flushed skin), Blind as a bat (cycloplegia), Mad as a hatter
Symptoms of muscarinic antagonist overdose
Bethanechol, carbachol, pilocarpine, methacholine
Direct cholinergic agonist drugs
Bethanechol
Direct cholinergic agonist; activates bowel and bladder post operation
Carbachol
Direct cholinergic agonist; used in glaucoma (causes pupillary contraction and reduces ICP)
Pilocarpine (PILE on the sweat and tears)
Direct cholinergic agonist; potent stimulator of sweat and tears
Methacholine
Direct cholinergic agonist; challenge test for asthma diagnosis
(-stigmine, Ed PHYSted the MAiLman and it ECHOed) Neostigmine, pyridostigmine, physostigmine, edrophonium, echothiophate, malathion
Indirect cholinergic agonist drugs (anticholinesterases)
Neostigmine (NEO CNS)
Indirect cholinergic agonist; used in post operative reversal of NMJ block; does NOT penetrate the CNS
Pyridostigmine
Indirect cholinergic agonist; used for myasthenia gravis (due to it’s long action); does NOT penetrate the CNS
Physostigmine (PHYS is for EYES)
Indirect cholinergic agonist; Used for glaucoma and atropine overdose (does cross CNS)
Edrophonium
Indirect cholinergic agonist; Used to diagnose myasthenia gravis (extremely short action)
Echothiophate
Indirect cholinergic agonist; used for glaucoma
Atropine, homatropine, tropicamide, benztropine, scopolamine, ipratropium, methscopolamine, oxybutynin, glycopyrrolate, pirenzepine, propantheline
Muscarinic antagonist drugs
Atropine (or homatropine, tropicamide)
Muscarinic antagonist drug(s); produces mydriasis and cycloplegia (eye)
Benztropine (PARK my BENZ)
Muscarinic antagonist drug; treatment for parkinson’s (CNS)
Scopolamine
Muscarinic antagonist drug; treatment of motion sickness (CNS)
Ipratropium
Muscarinic antagonist drug; treats asthma and COPD (respiratory)
Methscopolamine (or oxybutynin, glycopyrrolate)
Muscarinic antagonist drug(s); Reduces bladder urgency in cystitis and bladder spasms (GI)
Pirenzepine (or propantheline)
Muscarinic antagonist drug(s); treatment of peptic ulcers (GI)
Atropine
Muscarinic antagonist drug; Used to block DUMBBELSS; Toxicity: hot as a hare, dry as a bone, red as a beet, blind as a bat, mad as a hatter
Hexamethonium
Nicotinic antagonist; ganglion blocker, used in experimental models to prevent vaga reflex responses to BP changes
B1
Low doses of epinephrine are selective for what receptor?
Epinephrine
Drug used for anaphylaxis, open angle glaucoma, asthma and hypotension. Binds a1, a2, B1 and B2 receptors.
Norepinephrine
Drug used for hypotension. Binds a1, a2 > B1
Isoproterenol
Drug that binds B1 = B2. Used rarely for AV block
Dopamine
Drug used for shock (by increased renal perfusion), and heart failure. Binds D1 = D2 > B > a.
Dobutamine
Drug used for shock, heart failure, and cardiac stress test. Bind B1 > B2.
Dopamine is inotropic and chronotropic, Dobutamine is inotropic but not chronotropic.
What is the difference in inotropy and chronotropy between dopamine and dobutamine.
Phenylephrine.
Drug used for pupillary dilation, vasoconstriction, and nasal decongestion. Binds a1 > a2.
Albuterol
Drugs used for acute asthma. Binds B2>B1/
Terbutaline
Drug used to reduce premature uterine contractions. Binds B2 > B1.
Ritodrine
Drug used to reduce premature uterine contractions. Binds B2 only.
Amphetamine
Drug used to treat narcolepsy, obesity, ADD. Releases stored catecholamines.
Ephedrine
Drug used for nasal decongestion, urinary incontinence, and hypotension. Releases stored catecholamines.
Cocaine
Drug that causes vasoconstriction and local anesthesia. Inhibits reuptake of NE.
Clonidine, a-methyldopa
Drug used to treat hypertension (esp in renal disease because it prevents decrease in blood flow to kidney. Centrally acting a2 agonist.
Increased systolic and diastolic pressure, reflex bradycardia (all because a>B)
Effect of NE on systolic and diastolic BP, and heart rate.
Increased systolic (B1), decreased diastolic (B2) (wide PP, no change in mean BP), increased heart rate (B1)
Effect of epinephrine systolic, diastolic BP and heart rate
Decrease BP (sys and diastolic, B2), BIG increase in HR (B1) (isoproterenol = B > a)
Effect of isoproterenol on BP and heart rate
MAST (metaproterenol, albuterol, salmeterol, terbutaline)
Mnemonic for selective B2 agonists
Phenoxybenzamine (irreversible), Phentolamine (reversible, both nonselective alpha blockers)
Drugs (2) used in pheochromocytoma before tumor is removed. SE: orthostatic hypotension, reflex tachycardia
(a1 antagonists) Prazosin, Terazosin, doxazosin
Alpha antagonist used for hypertension and urinary retention in BPH. SE: first dose orthostatic hypotension
(a2 selective) Mirtazapine
Alpha antagonist used for depression. SE: sedation, inc serum cholesterol, inc appetite.
Dec CO, dec renin secretion (B1)
How do beta blockers effect hypertension
Dec mortality after MI
How are B blockers used in MI
Propanolol, esmolol
What B blockers are used in supraventricular tachycardia
Dec. AV conduction velocity (SVT)
What type of arrhythmia are B blockers used for
Dec secretion of aqueous humor (timolol)
How are B blockers used in glaucoma.
Impotence, exacerbates asthma, don’t use with diabetics
What are the side effects of B blockers
Propanolol, timolol, nadolol, pindolol, labetalol
What are the nonselective B blockers
A BEAM of B1 blockers (acebutolol, betaxolol, esmolol, atenolol, metoprolol)
What are the selective B1 blockers (mnemonic)
Carvedilol, labetalol
Nonselective alpha and beta antagonists
N-acetylcysteine
Treatment for overdose of acetaminophen
NaHCO3 (alkalinize urine), dialysis
Treatment for overdose of Salicylates
NH4Cl (acidify urine)
Treatment for overdose of amphetamines
Atropine, pralidoxime
Treatment for overdose of anticholinesterases, organophosphates
Physostigmine saligylate
Treatment for overdose of antimuscainic and anticholinergic agents
Glucagon
Treatment for overdose of B blockers
K+, lidocaine, digibind, Mg2+
Treatment for overdose of digitalis
Deferoxamine
Treatment for overdose of iron
CaEDTA, dimercaprol, succimer (kids), penicilamine
Treatment for overdose of lead
Dimercapol, succimer
Treatment for overdose of arsenic, mercury, gold
Penicillamine
Treatment for overdose of copper, arsenic, gold
Nitrite, hydroxycobalamin, thiosulfate
Treatment for overdose of cyanide
Methylene blue
Treatment for overdose of methemoglobin
100% O2, hyperbaric O2
Treatment for overdose of CO
Ehtanol, dialysis, fomezipol
Treatment for overdose of methanol or ethylene glycol (antifreeze)
Naloxone, naltrexone
Treatment for overdose of opiods
Flumazenil
Treatment for overdose of benzodiazapines
NaHCO3 (serum alkanization)
Treatment for overdose of TCAs
Protamine
Treatment for overdose of heparin
Vitamin K, fresh frozen plasma
Treatment for overdose of warfarin
Aminocaproic acid
Treatment for overdose of tPA, streptokinase
Lead poisining
Sx: lines on gingivae and long bone epiphyses, encephalopathy and erythrocyte basophilic stippling, abdominal colic, sideroblastic anemia, wrist and foot drop
Iron poisining
Acute poisining = gastric bleeding, chronic poisining = metaboic acidosis, GI obstruction (scarring). MOA = peroxidation of lipids
Tricyclics
What drugs give an atropine like side effect to the cardiovascular system?
Cocaine, sumatripan
What drugs (2) cause coronary vasospasm as a side effect?
Niacin, Ca channel blockers, adenosine, vancomycin
What drugs (4) cause cutaneous flushing as a side effect
Doxorubicin, daunorubicin
What drugs (2) cause dilated cardiomyopathy as a side effect
Class III antiarrythmics (sotalol), Class IA (quinidine) antiarrhythmics, cisapride
What drugs (3) cause torsades de pointes as a side effect
Clozapine, carbamazapine, colchicine, propylthiouracil, methimazole
What drugs (5) can cause agranulocytosis as a side effect
Chloramphenicol, benzene, NSAIDs, propylthiouracil, methimazole
What drugs (5) can cause Aplastic anemia as a side effect
Methyldopa
What drug can give a direct positive coomb’s hemolytic anemia?
Chloramphenicol
What drug can cause grey baby syndrome as a side effect
INH, sulfonamides, primaquin, aspirin, ibuprofen, nitrofurantoin (hemolysis IS PAIN)
What drugs (6 - mnemonic) can cause hemolysis in G6PD patients.
OCPs (estrogen and progestins)
What drug class can cause thrombotic compications as a side effect?
ACE inhibitors (NOT ARBs)
What drug causes a dry cough as a side effect?
Bleomycin, busulfan, amiodarone
What drugs (3) can cause pulmonary fibrosis as a side effect?
Macrolides
What drug can cause acute cholestatic hepatitis as a side effect?
Halothane, valproic acid, acetominophen, Amanita phalloides
What drus (4) can cause focal to massive hepatic necrosis as a side effect?
INH
What drug can cause hepatitis as a side effect?
Clindamycin, ampicillin
What drugs (2) can cause psuedomembranous colitis as a side effect?
Glucocorticoid withdrawal
What drug can cause adrenocortical insufficiency as a side effect
Spironolactone, digitalis, cimetidine, chronic alcohol use, estrogens, ketoconazole (Some Drugs Create Awesome Knockers)
What drugs (6) can cause gynecomastia as a side effect? (mnemonic)
Tamoxifen, clomiphene
What drugs (2) can cause hot flashes as a side effect?
Phenytoin
What drug causes gingival hyperplasia as a side effect?
Furosemide, thiazides
What drugs (2) can cause gout as a side effect
Corticosteroids, heparin
What drugs (2) can cause osteoporosis as a side effect?
Sulfonamides, Amiodarone, Tetracycline (SAT for a PHOTO)
What drugs (3) can cause photosensitivity as a side effect (mnemonic)?
Hydralazine, INH, procainamide, phenytoin (it’s not HIPP to have lupus)
What drugs (4) can cause an SLE-like syndrome as a side effect?
Fluoroquinalones
What drug causes tendonitis, tendon rupture and cartilage damage as a side effect in kids?
Expired tetracycline
What drug causes Fanconi’s syndrome as a side effect
Methicillin, NSAIDs
What drugs (2) cause interstitial nephritis as a side effect?
Cyclophosphamide, ifosfamide
What drugs (2) cause hemorrhagic cystitis as a side effect?
Quinidine, quinine
What drugs (2) cause cinchonism as a side effect?
Lithium, demeclocycline
What drugs (2) cause diabetes insipidus as a side effect
Bupropion, imipenem/cilastin
What drugs (2) cause seizures as a side effect?
Antipsychotics (typical)
What drugs cause tardive dyskinesia?
Metronidazole, cephalosporins (some), procarbazine, 1st generation sulfonylureas
What drugs (4) cause a disulfiram-like reaction as a side effect
Polymixins
What drug causes nephrotoxicity and neurotoxicity as side effects?
Aminoglycosides, loop diuretics, cisplatin
What drugs (3) cause nephrotoxicity and ototoxicity as a side effect?
Queen barb takes Phen-phen and Refuses Greasy Card Shakes (quinidine, barbiturates, phenytoin, rifampin, griseofulvin, carbamazapine, st. john’s wart)
Mnemonic for p450 inducers
Inhibitors Stop Cyber-Kids from Eating Grapefruit (INH, sulfonamides, cimetidine, ketoconazole, erythromycin, grapefruit juice)
Mnemonic for p450 inhibitors
Coadminister with mesna
Method to prevent hymorrhagic cystitis caused by cyclophosphamide or ifosfamide
Oxalic acid
What is ethylene glycol converted to in the body
Acidosis, nephrotoxicity
What does oxalic acid (metabolic product of ethylene glycol) cause?
Formaldehyde and formic acid
What metabolic products (2) is methanol converted to in the body
Severe acidosis, and retinal damage
What are the effects of formaldehyde and formic acid (metabolic products of methanol) in the body?
Acetaldehyde
What is ethanol broken down by in the body?
Alcohol dehydrogenase
What enzyme breaks down ethylene glycol, methanol, and ethanol?
Fomepizole
Inhibitor of alcohol DH
Sulfa drugs (celcoxib, furosemide, thiazides, TMP-SMX, sulfonyureas, sulfasalazine
What drugs do you not give people with sulfa allergies
Ephedra
Herbal agent that can cause arrythmias, stroke, and seizures at high doses
Feverfew (migraines) and ginko (claudication)
Herbal agents that have antiplatelet actions
Kava (chronic anxiety)
Herbal agent that can cause phototoxicity and dermatotoxicity
Saw palmetto (benign prostatic hyperplasia)
Herbal agent that can cause hypertension
St. John’s wort (depression)
Herbal agent that can cause serotonin syndrome w/ ssris, and induces p-450
Dehydroepiandosterone (SLE or AIDs)
Herbal agent that causes androgenization in premenopausal women, and estrogen effects in postmenopausal women and feminization in young men