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librarian — Wed, 14 Mar 2007 15:21:01 +0900

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Kaplan medical Explains To Released Items 2006 Edition

USMLE Library Bookmarks 2007.03.05

librarian — Mon, 05 Mar 2007 15:00:17 +0900

USMLE Library Bookmarks 2007.03.05
bookmarks.usmlelibrary.com

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Local anesthetics

librarian — Sat, 03 Mar 2007 12:19:28 +0900

Local anesthetics

Esters	Amides
metabolized by plasma cholinesterases & hepatic esterases	metabolized by hepatic amidases
procaine chloroprocaine benzocaine cocaine tetracaine	mepivacaine lidocaine bupivacaine etidocaine prilocaine ropivacaine

Treatment of Wegener's granulomatosis

librarian — Fri, 02 Mar 2007 18:32:49 +0900

Treatment of Wegener's granulomatosis

corticosteroids
cyclophosphamide

complicatioins of cyclophosphamide

hemorrhagic cystitis (can be prevented by mesna)

transitional cell carcinoma of the bladder

Common pathogens and manifestations

librarian — Fri, 02 Mar 2007 18:23:28 +0900

Disease	Pathogen	Manifestation
Cholera	Vibrio cholera	"rice-water" diarrhea
Typhoid fever	S. typhi	"rose spots" on abdomen
Kawasaki disease	Unknown	"strawberry tongue"
Scarlet fever	Group A streptococcus	"strawberry tongue"

Manifestations of disseminated gonococcemia

librarian — Fri, 02 Mar 2007 17:12:42 +0900

Manifestations of disseminated gonococcemia

S: Synovitis
T: Tenosynovitis
D: Dermatitis

Common side effects

librarian — Fri, 02 Mar 2007 16:43:41 +0900

Drug	Mechanism	Ix	Side Effects
Quinidine	antiarrhythmics	atrial fibrillation ventricular arrhythmias	cinchonism tinnitus blurred vision GI upset delirium
Allopurinol		gout	rash fever
Hydralazine	a vasodilator	hypertension	tachycardia headache nausea a lupus-like syndrome
Niacin		hyperlipidemia	flushing pruritus
Spironolactone	a K⁺ sparing diuretic blocks aldosterone effects		hyperkalemia gynecomastia
Sumatriptan	serotonin 1D agonist	migraine headache cluster headache
Trazodone	antideprressant		priapism (painful erection for an extended period of time. Tx: inj. of alpha agonist: NE, Epi,...)
Atenolol	Beta 1 blocker	hypertension	impotence
Furosemide	a loop diuretic	edema hypertension	electrolyte abnormalities
Sulfonyl urea glyburide	an oral hypogrycemic agent	type 2 DM	hypoglycemia
Paroxetine	an SSRI	depression	impotence

Cycloplegia

librarian — Fri, 02 Mar 2007 10:47:14 +0900

Cycloplegia

paralysis of the cilliary muscle -> resulting in loss of accomodation

Drugs which have effects on AV conduction

librarian — Mon, 26 Feb 2007 13:20:00 +0900

Drugs	Mechanism	AV conduction
Digitalis	parasympathomimetic actions	decreases
Quinidine	centrally decreases vagal tone	increases
Nicotine	stimulates sympathetic autonomic ganglia adrenal medulla	increases
Atropine	blocks cardiac muscarinic receptors	increases
NE	stimulates cardiac beta receptors	increases

Fibromyalgia (fibrositis)

librarian — Mon, 26 Feb 2007 12:53:00 +0900

Fibromyalgia (fibrositis)

Sx

age 20~50
wide spread chronic musculoskeletal pain that improves with exercise
chronic fatigue
headache

Signs

painful trigger points on trapezius, lateral epicondyle
no signs of inflammation
normal lab findings

TCAs (amitriptyline, ...)
Skeletal m. relaxants (cyclobenzaprine, ...)

Parkinson's disease

librarian — Mon, 26 Feb 2007 12:33:31 +0900

Parkinson's disease

Sx

resting tremor (decreases with active movement)
expressioinless face
soft voice
cogwheel rigidity
slightly stooped posture
slow, shuffling gait

Levodopa:

a dopamine precursor that increases circulating dopamine levels in the striatum
most effective.

Selegiline (deprenyl):

slows the breakdown of dopamine -> prolongs the clinical effects of levodopa.

Selegiline inhibits MAO-B which metabolizes dopamine
(MAO-A metabolizes NE & serotonin)

Benztropine:

a muscarinic antagonist

maintaining the balance of cholinergic & dopaminergic neurotransmission in the neostriatum
improves tremor & rigidity
(little effect on the bradykinesia)

Trihexyphenidyl

a muscarinic antagonist
adjunctive therapy in Parkinson's disease
improves tremor, rigidity
(little effect on bradykinesia)
Side effects: by blocking parasympathetic tone

dry mouth <- decreased salivation
decreased sweating
constipation
mydriasis
urinary retention

Bromocriptine:

a dopamine receptor agonist

Pergolido:

a dopamine receptor agonist

Epinephrine reversal

librarian — Mon, 26 Feb 2007 01:42:00 +0900

Epinephrine reversal

Epinephrine, originally increases BP, produces opposite effect after phentolamine administration

Trihexyphenidyl

librarian — Mon, 26 Feb 2007 00:38:00 +0900

Trihexyphenidyl

a muscarinic antagonist
adjunctive therapy in Parkinson's disease
improves tremor, rigidity
(little effect on bradykinesia)
Side effects: by blocking parasympathetic tone

dry mouth <- decreased salivation
decreased sweating
constipation
mydriasis
urinary retention

Side effects

librarian — Sun, 25 Feb 2007 23:16:00 +0900

Drungs	Mechanism	Side effects
Captopril	an ACEI	dry cough headache diarrhea fatigue nausea dizziness
Aspirin	an NSAID	increased bleeding time GI bleeding tinnitus
Warfarin	an oral anticoagulant	bleeding fetal bone defects
Metoprolol	a beta 1 antagonist	hypoglycemia peripheral vasoconstriction CNS side effects
Procaineamide	a group IV antiarrhythmics	antimuscarinic direct depressant effects on the heart reversible syndrome similar to LE

Piperidines

librarian — Sun, 25 Feb 2007 23:10:00 +0900

Piperidines
: does not cross BBB, does not cause sedation

terfenadine
astemizole
loratadine

Drugs which potentiate the effects of warfarin

librarian — Sun, 25 Feb 2007 22:07:00 +0900

Drugs which potentiate the effects of warfarin
by decreasing the metabolism of warfarin

Macrolides

erythromycin
metronidazole
sulfonamide

Norfloxacin
cephalosporins with methyltetrazolethiol side chain

cefazolin
cefmetazole
cefoperazone

(large IV dose of penicillin)

Treatment of non-Hodgkins lymphoma

librarian — Sun, 25 Feb 2007 20:45:00 +0900

Treatment of non-Hodgkins lymphoma

Nitrogen mustards (ifosfamide, cyclophosphamide)

Complication of nitrogen mustards

hemorrhagic cystitis
sudden onset of dysuria, frequency
bacteriuria (-)
gross hematuria
bladder obstruction by blood clots

Prevention of hemorrhagic cystitis

mesna - reacts with urotoxic metabolites from nitrogen mustards

Antidotes for overdoses

librarian — Sun, 25 Feb 2007 19:06:27 +0900

Overdoses	Antidotes	Mechanism
Benzodiazepines (midazolam, ...)	Flumazenil
Beta blocker	Glucagon
Opioid	Naloxone
Cyanide	Nitrite
Heparin	Protamine
Acetaminophen	N-acetylcysteine
AchE inhibitors (organophosphates like parathion)	pralidoxime	AchE reactivation
	Atropine	a nonselective muscarinic antagonist inhibits Ach stimulation on muscarinic receptors
Antimuscarinic	physostigmaine	carbamylating AchE inhibition
Iron	Deferoxamine	chelation
Arsenic	Dimercaprol	chelation
Mercury	Dimercaprol	chelation
Gold	Dimercaprol	chelation
Lead	Dimercaprol + EDTA penicillamine
Cyanide	sodium thiosulfate

nitrogen mustards (cyclophosphamide, ifosfamide)	mesna	reacts with urotoxic metabolites from nitrogen mustards
methotrexate (an anti-neoplastic folic acid antagonist)	leucovorin
(Wilson's disease)	penicillamine	increases renal excretion of excess copper
(Advanced RA)	penicillamine

Inflammatory bowel diseases

librarian — Sun, 25 Feb 2007 18:33:20 +0900

	Crohn's disease	Ulcerative colitis
Possible etiology	Infection	Autoimmune
Location	skip lesions rectal sparing	continuous lesions rectal involvement (always)
Gross morphology	Transmural inflammation Cobblestone mucosa Creeping fat Bowel wall thickening -> "string sign" on barieum enema Linear ulcers Fissures Fistulas	mucosal & submucosal inflammation only friable mucosal pseudopolyps with freely hanging mesentery
X-ray	small intestine & colon ulceration stricturing fistulas
Microscopic morphology	noncaseating granulomas lymphoid aggregates	crypt abscesses, ulcers, bleeding (no granulomas)
Complications	strictures fistulars perianal disease malabsorption nutritional depletion	severe stenosis toxic megacolon colorectal carcinoma
Extraintestinal manifestations	migratory polyarthritis erythema nodosum ankylosing spondylitis uveitis immunologic disorders	pyoderma gangrenosum primary sclerosing cholangitis
Sx	low grade fever diarrhea malaise weight loss focal tenderness palpable tender mass (lower abdomen)
Tx	nonpharmacologic therapy corticosteroids (prednisone, ...) on acute 'flare-ups'	hydrocortisone suppositories mesalamine (a 5-aminosalicylic acid derivative)

Loading dose vs. Maintenace dose

librarian — Sun, 25 Feb 2007 14:35:39 +0900

Loading dose
= Cp x Vd / F

Cp: Plasma concentratioin
Vd: Volume of distribution
F: Bioavailability

Maintenace dose
administer the cleared amount (typically every half-life)
= Cl x Cpss / F

Cl: Clearance
Cpss: plasma concentration at steady state
F: Bioavailability (100% when administered IV)

Indirect-acting Sympathomimetics

librarian — Fri, 23 Feb 2007 23:12:39 +0900

Indirect-acting Sympathomimetics

(Meth)amphetamine:

increase CNS dopamin release -> reinforcing effects (reward system)
induction of NE release -> systemic effects (e.g., hypertension)
increase serotonin release
weakly inhibits MAO -> weakly blocks the metabolism of catecholamines

Cocaine:

increase CNS dopamin release
Blocking NE reuptake
-> increase BP, HR

Pharmacologic Tx of seizures

librarian — Thu, 22 Feb 2007 12:52:57 +0900

Anticonvulsants	Ix	Advers effects
Phenytoin	grand mal seizure tonic-clonic seizure	diplopia gingival hyperplasia hirsutism nystagmus sedation ataxia enzyme induction
Carbamazepine	tonic-clonic seizure partial seizures tic douloureux	diplopia ataxia enzyme induction blood dyscrasias
Ethosuximide	absence seizure only	GI distress headache lethargy
Phenobarbital	grand mal seizure partial seizure	sedation enzyme induction dependence
Valproic acid	all types of seizure (esp. myoclonic seizure, petit mal seizure)	GI distress hepatotoxicity inhibition of drug metabolism

Pharmacologic Tx of hypertension

librarian — Thu, 22 Feb 2007 12:31:05 +0900

Pharmacologic Tx of hypertension

ACEIs

blocking conversion of angiotensin I to II

CCBs (nifedipine, verapamil, diltiazem)

blocking calcium entry into cells -> inhibiting vascular smooth m. contraction

Centrally acting sympatholytics (clonidine)

blocking adrenergic receptors in the brain -> reducing sympathetic outflow

Nitrates (nitroglycerin)

release nitric oxide in smooth m. cells -> stimulating guanylate cyclase -> increase in cGMP -> smooth m. relaxation & vasodilation

Thiazides (hydrochlorothiazide)

act on early distal tubule

Adverse effects of niacin (nicotinic acid, Vitamin B3)

librarian — Thu, 22 Feb 2007 12:17:23 +0900

Adverse effects of niacin (nicotinic acid, Vitamin B₃)

generalized flushing, sensation of facial warmth
hepatotoxicity
tachycardia
hypoalbuminemia
hyperglycemia
nausea, vomiting
hyperuricemia
glucose intolerance
pruritius
peptic ulcer disease
dry skin

Congestive heart failure (CHF)

librarian — Thu, 22 Feb 2007 11:59:59 +0900

Major criteria for Dx of CHF

paroxysmal nocturnal dyspnea
neck vein distension
rales
cardiomegaly
acute pulmonary edema
S3 gallop
increased venous pressure (> 16cmH₂O)
positive hepatojugular reflex

Adaptive mechanism for compensation

increasing pre-load
myocardial hypertrophy
redistribution (from nonvital organs to vital organs)
neurohumoral adjustments

ACEIs - standard therapy

protective effects
vasodilation
blocking the detrimental neurohormonal activity

Furosemide, hydrochlorothiazide

furosemide: 1st-line agent
edema assiciated with CHF, hepatic cirrhosis, renal disease
hypertension

verapamil: a CCB

Tx of hypertension, arrhythmia
Contraindicated in Tx of CHF due to strong negative inotropic effect

Henderson-Hasselbalch equation

librarian — Wed, 21 Feb 2007 17:53:00 +0900

Henderson-Hasselbalch equation

pH = pKa - log[HA/A^-]

HA: protonated form
A^-: unprotonated form

the uncharged, lipid-soluble form can be rapidly absorbed.
the protonated form is uncharged.

Propylthiouracil

librarian — Wed, 21 Feb 2007 16:48:00 +0900

Propylthiouracil inhibits peripheral conversion of T4 to T3.
T3 is several times more potent than T4.

Side effects of Doxorubicin (Adriamycin)

librarian — Wed, 21 Feb 2007 15:31:00 +0900

Side effects of Doxorubicin (Adriamycin) - an anthracycline antibiotic

cardiomyopathy -> CHF, pulmonary edema, rales. esp. in

age > 70
cardiac irradiation
underlying heart disease or hypertensioin
received cyclophosphamide

alopecia
BM suppression

Side effects of metronidazole

librarian — Wed, 21 Feb 2007 15:29:00 +0900

Side effects of metronidazole

headaches
dizziness
diarrhea
rashes

Cimetidine

librarian — Wed, 21 Feb 2007 14:26:00 +0900

Cimetidine
- an H₂ blocker
- side effects in long term use

bowel habit change
headache
dizziness
skin rashes
loss of libido
gynecomastia
alteration of hepatic metabolism of several drugs

(Famotidine does not have the side effects of cimetidine)

USMLE Library Blog

Links to the USMLE Step 1 Sample Questions & Answers

USMLE Library Bookmarks 2007.03.05

Local anesthetics

Treatment of Wegener's granulomatosis

Common pathogens and manifestations

Manifestations of disseminated gonococcemia

Common side effects

Cycloplegia

Drugs which have effects on AV conduction

Fibromyalgia (fibrositis)

Parkinson's disease

Epinephrine reversal

Trihexyphenidyl

Side effects

Piperidines

Drugs which potentiate the effects of warfarin

Treatment of non-Hodgkins lymphoma

Antidotes for overdoses

Inflammatory bowel diseases

Loading dose vs. Maintenace dose

Indirect-acting Sympathomimetics

Pharmacologic Tx of seizures

Anticonvulsants

Ix

Advers effects

Pharmacologic Tx of hypertension

Adverse effects of niacin (nicotinic acid, Vitamin B3)

Congestive heart failure (CHF)

Henderson-Hasselbalch equation

Propylthiouracil

Side effects of Doxorubicin (Adriamycin)

Side effects of metronidazole

Cimetidine