Opposites: SIADH vs DI drugs

SIADH Drugs:

Acetaminophen
Barbiturates
Carbamazepine
Chlorpropamide
Clofibrate
Cyclophosphamide
Indomethacin
Isoproterenol
PGE1
Meperidine
Nicotine
Tolbutamide
Vincristine

Diabetes Insipidus Drugs:

Ethanol
Phenytoin
Chlorpromazine
Lithium
Demeclocycline
Glyburide
Amphoterocin B
Colchicine
Vinblastine

Bicycles in my urine!

There are two important "cycle" drugs that cause problems in the GU system. Picture a bunch of bicycles riding around in the renal tubules and bladder. The first drug is a"cyclo"vir which crystalizes in the renal tubules. The other drug is "cyclo"phosphamide which causes the infamous hemorrhagic cystitis which is prevented with mesna.

My approach to diuretic questions

DDx of diuretics

1. Loops
2. Thiazides
3. K+ sparing
4. Acetazolamide
   

My first rule: all diuretics cause hypokalemia except for 3 drugs (potassium sparing diuretics)

1. Spironolactone (competitive aldosterone antagonist, also interferes with testosterone synthesis causing incr estradiol in treating hirsutism in PCOS. Spironolactone has been shown to improve mortality in patients with CHF by blocking the toxicity of aldosterone as it hits the heart. (Weird MOA)
2. Amiloride (inhibits directly, the Na/K pump in the DCT)
3. Triamterene (same MOA amiloride)

To separate all of the diuretics that cause hypokalemia, look at the [Ca++] to separate loops and thiazides.

1. Loops lose everything including Ca++, so if the patient is hypokalemic and hypocalcemic, they are probably on a loop (furosemide, torsemide, ethacrynic Acid, bumetanide) be careful of ethacrynic acid, it's name doesn’t look like a loop at all!
2. Thiazides cause increased Ca++ reabsorption from renal tubules so they cause hypercalcemia, but they are used to treat calcium renal stones because they decrease Ca++ in the tubules, where it is causing the problem.
   

To separate acetazolamide from loops and thiazides, look at the acid-base status.

1. Acetazolamide is one of the few things that causes a metabolic acidosis with hypokalemia. Acetazolamide is a carbonic anhydrase inhibitor producing an alkaline diuresis. (you pee bicarb, and with the bicarb, Na follows). Usually, acidosis goes with hyperkalemia. Acetazolamide is also used to decr aqueous humor production and to treat acute mountain sickness.

Be aware that licorice acts like aldosterone, so it can cause hypokalemia.

ACE-I and Digoxin causes hyperkalemia so watch these drugs with spironolactone.

If you get a question w/ Bartter’s Syndrome (mutation of the Na+/K+/2Cl- cotransporter in TAL, just look for the lab values that match a loop diuretic (remember loops LOSE everything). You must rule out diuretic abuse in a patient you suspect has Bartter’s Sydrome.

Highly protein bound drugs

Warfarin, phenytoin, valproic acid, diazepam

o Generally have low volumes of distribution

o Can be displaced and are usually lipid soluble

PGE1 agonists

Misoprostol: used for prophylaxis of GI ulcers when on NSAIDS. Think of drinking "miso" soup to help your stomach pain. Look at the "prost" to remind yourself of its MOA, prostaglandin E1 agonist.

Alprostadil (prostaglandin E1): maintains patency of ductus arteriosus (opposite of what indomethacin or any NSAID does). Look at the "prost" to remind yourself of the MOA, PGE1 agonist and look at the "dil" to remind yourself that it DILates the PDA.

DDx Diarrhea in AIDS patients

Diarrhea in HIV/AIDS

---

DDx

Viral: CMV colitis, also causes CMV esophagitis Bacterial: Campylobacter, Salmonella, Shigella, Clostridium difficile, Mycobacterium avium complex (MAC), tuberculosis Protozoal: Cryptosporidium (no real treatment available) Entamoeba histolytica (amoebic dysentery, look for liver abscess as well) Giardia (watery diarrhea, often prolonged, with bloating, gas and malabsorption; upper GI symptoms w/ lower GI symptoms; risk factors: anal sex and drinking "pure" mountain water) Isospora, microsporidia HIV-associated malabsorption

What's in a name... Amiodarone

• Amiodarone
• Iodine: think iodine in the lungs (pulmonary fibrosis, iodine in the liver (hepatic necrosis), iodine in the eyes (corneal deposits), iodine in the skin (smurf skin, phototoxicity), iodine is also in thyroid hormone (thyroid dysfunction).

What's in a number?

If you didn't notice, I reformatted the goljan lectures to 1.618 times speed. I will send my biochem on crack usmle lectures the first person who leaves a comment correctly identifying the significance of the ratio 1.618.

Chemotactic Factors

• Chemotactic Factors for Neutrophils
• Bacterial Products (i.e. teichoic acid)
  
• Components of the complement system, particularly C5a
• Products of the arachidonic acid metabolism, particularly
• Leukotriene B4
• Chemotactic Factors for Monoctyes
• Bacterial Products
• C5a components of complement
• Fibrinopeptides
• Leukotriene B4
• Lymphokines
• Growth factors (PDGF, TGFB)
• Fragments of collagen and/or fibronectin
• Chemotactic factors for Eosinophils
• Leukotriene B4
• Prostaglandin D2
• Histamine
• Eosinophil chemotactic factor of anaphylaxis

My Antibiotics Lecture

Nitroprusside

Nitroprusside has an important indication for the treatment of hypertensive emergencies. However, it is more famous for its side-effect, i.e. cyanide poisoning. How do we associate nitroprusside with cyanide poisoning?

o We already associate Prussian with blue (i.e. “Prussian Blue”)

o Cyanide (cyan is a bluish color)

o So we know that nitroprusside has blue in it from cyanide

o If you use nitroprusside for too long, you can cause cyanide poisoning.

Coombs vs Indirect Coombs

What's in a name?

A very famous question on the boards is what clotting factor enoxaprin works on. The answer is in its name; enoXaprin works on factor Xa!

Is the ampicillin rash the new MonoSpot for EBV?

the sensitivity of the monospot for EBV is 85%. if you give ampicillin to a patient with EBV, >90% will get a maculopapular rash. this means that if a person has infectious mono, they are more likely to break out into a rash after receiving ampicillin than having a positive monospot test.

fyi: up to 80% of patients with CLL also break out into a rash after receiving ampicillin.

Adenosine vs. Theophylline

These drugs have opposite actions on same receptors: adenosine treats arrhythmias but causes asthma, theophylline causes arrhythmias but treats asthma

Abnormal Cell Counts in various fluids

Should culture fluids with these abnormal cell counts

• CSF>5
• Urine>10
• Ascites>250 pmn's or >500 wbc's
• Joint>2,000 for inflammation or >20,000 for infection

So in other words, your brain should have the least wbc's followed by your pee, belly and joints.

Skin findings in conditions with GI bleeding

• Pigmented macules on lips, palms and soles: Peutz-Jegers
• Cafe au lait spots: Neurofibromatosis
• Spider angiomata: liver cirrhosis
• Acanthosis nigricans: neoplasm
• Fragile skin and keloids: Ehlers Danlos
• Webbed neck, purpura and skin nodules: Turner's syndrome
  

Cardiac drugs that induce pulmonary symptoms/disease.

• Amiodarone - pneumonitis and pulmonary fibrosis
• Beta blockers - bronchoconstriction (especially with BB's N-Z)
  
• ACE-I - dry cough (take patient off of ACE-I and put on ARB)
  
• Drug induced SLE (hydralazine, INH, procainamide, etc) - pleurisy (anti-histone antibodies)
• Aspirin - Sampter's triad (rhinitis, nasal polyps, bronchospasm/asthma; if i see nasal polyps in a question I am immediately looking for aspirin or asthma in the answer)

Why are patients with SIADH normovolemic?

Increased ADH with H2O intake causes increased ECF. This volume expansion activates the volume receptors in the heart and causes the release of ANP. ANP causes naturesis w/ some kaliuresis and diuresis. The loss of Na keeps enables the body to have a normal volume.

DDx of exophthalmos

DDx

Graves’ ophthalmopathy (B/L) Tumor (usually unilateral) Hand-Schuller-Christian disease (eosinophilic granuloma)

DDx of Pulseless electrical activity (PEA)

’CHEAPMD’ (mnemonic) Cardiac Tamponade Hypoxia, Hypovolemia, Hypothermia, Hyperkalemia Embolism (massive pulmonary embolism) Acidosis Pneumothorax (tension pneumothorax) Myocardial Infarction Drug overdose, eg, tricyclic antidepressant, digoxin, beta blocker, calcium channel blocker

Paraneoplastic Syndromes

Etiology

(++ = strong association; + = reported association) Endocrine Cushing's syndrome Small-cell lung cancer: ++ Non-small-cell lung cancer: + Gonadotropin excess Small-cell lung cancer: ++ Non-small-cell lung cancer: + Gastrointestinal cancers: + Gestational trophoblastic disease: + Renal cell cancer: + Carcinoid: + Hypercalcemia Small-cell lung cancer: ++ Non-small-cell lung cancer: + Breast cancer: + Multiple myeloma: + Lymphoma: + Prostate cancer: + Hyperthyroidism Gestational trophoblastic disease: + Hypoglycemia Gastrointestinal cancers: + Hepatocellular cancer: + SIADH Small-cell lung cancer: ++ Non-small-cell lung cancer: + Neuromuscular Dermatomyositis/polymyositis Small-cell lung cancer: ++ Non-small-cell lung cancer: + Breast cancer: + Gastrointestinal cancers: ++ Ovarian cancer: + Myeloproliferative disease: + Lambert-Eaton syndrome Small-cell lung cancer: ++ Breast cancer: + Gastrointestinal cancers: + Ovarian cancer: + Sensorimotor peripheral neuropathy Small-cell lung cancer: ++ Non-small-cell lung cancer: + Stiff man syndrome Breast cancer: + Ovarian cancer: + Subacute cerebellar degeneration Small-cell lung cancer: ++ Non-small-cell lung cancer: + Gastrointestinal cancers: + Lymphoma: + Ovarian cancer: + Skin Acanthosis nigricans Non-small-cell lung cancer: + Breast cancer: + Gastrointestinal cancers: + Carcinoid: + Prostate cancer: + Myeloproliferative disease: + Dermatomyositis Small-cell lung cancer: ++ Non-small-cell lung cancer: + Breast cancer: + Gastrointestinal cancers: ++ Ovarian cancer: + Myeloproliferative disease: + Sweet's syndrome Non-small-cell lung cancer: + Breast cancer: + Gastrointestinal cancers: + Lymphoma: ++ Renal cell cancer: + Ovarian cancer: + Prostate cancer: + Myeloproliferative disease: ++ Hematologic Coagulopathy Breast cancer: + Lymphoma: + Renal cell cancer: + Carcinoid: + Prostate cancer: + Myeloproliferative disease: + Eosinophilia Lymphoma: ++ Erythrocytosis Hepatocellular cancer: + Renal cell cancer: + Ovarian cancer: + Adrenocortical tumors: + Cerebellar hemangioblastomas: + Pure red cell aplasia Non-small-cell lung cancer: + Breast cancer: + Gastrointestinal cancers: + Lymphoma: + Thymoma: ++ Thrombocytosis Small-cell lung cancer: + Non-small-cell lung cancer: + Breast cancer: + Multiple myeloma: + Gastrointestinal cancers: + Hepatocellular cancer: + Gestational trophoblastic disease: + Lymphoma: + Renal cell cancer: + Carcinoid: + Thymoma: + Ovarian cancer: + Prostate cancer: + Myeloproliferative disease: + Adrenocortical tumors: + Cerebellar hemangioblastomas: + Fever Small-cell lung cancer: + Non-small-cell lung cancer: + Breast cancer: + Multiple myeloma: + Gastrointestinal cancers: + Hepatocellular cancer: + Gestational trophoblastic disease: + Lymphoma: + Renal cell cancer: + Carcinoid: + Thymoma: + Ovarian cancer: + Prostate cancer: + Myeloproliferative disease: + Adrenocortical tumors: + Cerebellar hemangioblastomas: + Amyloidosis Multiple myeloma: + Lymphoma: + Renal cell cancer: +

Pearl of the Day: DDx of Relative Bradycardia

Salmonella typhi, leptospirosis, brucelliosis, facticious, beta blocker

Cool infectious disease site!

Check out Persiflagers Annotated Compendium of Infectious Disease (PACID). This site is filled with great practical advice and excellent pearls for infectious diseases.

Best Programs for your Blackberry, Palm, Pocket PC

1. Pepid Clinical Rotation Companion - best program by far. Has an excellent disease database, drug list and medical calculator. Major drawback is it's price, but you get 1 free month trial. (pepid.com Blackberry, Palm, Pocket PC)
   
2. iSilo - allows you to carry Harrisons, Washington Manual, Robbins, Netter's, etc in your palm. There is now a beta release of iSilo for the blackberry. Best feature is the ability search entire document. (isilo.com Blackberry, Palm, Pocket PC)
3. Epocrates (free version) - The minimum any student should have on their palm for drug references. (epocrates.com Blackberry, Palm, Pocket PC)
   

Female pathology by age

Where in the brain?

Bile Acid Secretion

Acid secretion in stomach

Sinusitis and Wegener's Granulomatosis

Granulomatous diseases of the lung

Sulfonamides

Quinolones

Drugs to use in pregnancy

Neonatal Infections

High Yield Zoonotic Infections

Bacteria stains

Gram negative rods

Bacteria flow sheet

Hypersensitivity Reactions

Primary Bone tumors by age

• 1st or 2nd decade: Ewing's Sarcoma
  
• Location: diaphysis of long bones
  
• t(11;22)(q24;q12)
• characteristic "onion skin" periosteal reaction on plain XR.
• 10-25 yrs: Oseosarcoma/Osteogenic Sarcoma
  
• "fir-tree" or "sun-burst" appearance on X-ray examination
• Codman's triangle - periosteum lifted into a triangle as the tumour emerges through the cortex
• the American Cancer Society states: "Probably in no other cancer is it as important to perform this procedure properly. An improperly performed biopsy may make it difficult to save the affected limb from amputation"
• Location: metaphysis
• "far from the elbow, close to the knee"
• proximal humerous, the distal radius, the distal femur and the tibia
  
• >30 yrs: Chondrosarcoma
• >50 yrs: Multiple Myeloma

How to keep the locations of Ewing's vs Osteosarcoma straight...
"E" is closer to "D" (Ewing's-Diaphysis)
"O" is closer to "M" (Osteosarcoma-Metaphysis)

Familial syndromes causing sarcomas include:

• neurofibromatosis
• familial retinoblastoma
• Li-Fraumeni syndrome
• Beckwith-Wiedemann syndrome
• basal cell nevus
• Gardner syndrome

Vasculitides

Monoclonal Antibodies... what's up with the name abciximab?

The following guidelines have been developed for monoclonal antibodies:

1. The suffix -mab is used for monoclonal antibodies and fragments.

2. Identification of the animal source of the product is an important safety factor based on the number of products that may cause source-specific antibodies to develop in patients.

The following letters were approved as product source identifiers:

u = human
o = mouse
a = rat
zu = humanized
e = hamster
i = primate
xi = chimera
axo = rat/mouse
xizu = combination of humanized and chimeric chains

These identifiers are used as infixes preceding the -mab suffix stem, eg:

-umab (human)
-omab (mouse)
-ximab (chimera)
-zumab (humanized)

Subclasses
The general disease state subclass must be incorporated into the name by use of a code syllable. The following disease state subclasses were approved based on products currently before the Council. Additional subclasses will be added as necessary.

Disease or Target Class:

Viral	-vir-
Bacterial	-bac-
Immune	-lim-
Infectious Lesions	-les-
Cardiovascular	-cir-
Antifungal	-fung-
Neurologic	-ner-
Interleukins	-kin-
Musculoskeletal	-mul-
Bone	-os-
Toxin as target	-toxa-

Tumors

Adalimumab

infliximab

colon	-col-
melanoma	-mel-
mammary	-mar-
testis	-got-
ovary	-gov-
prostate	-pr(o)-
miscellaneous	-tum-

• In order to create a unique name, a distinct, compatible syllable should be selected as the starting prefix.
• Sequence of stems: The order for combining the key elements is as follows: Infix representing the target disease state, the source of the product, and the monoclonal root -mab used as a suffix (eg, biciromab, satumomab, nebacumab, sevirumab, tuvirumab). When combining a target or disease infix stem with the source stem for chimeric monoclonal antibody, the last consonant of the target/disease syllable is dropped, eg:

TARGET	SOURCE	-MAB STEM	USAN
-cir-	-xi	-mab	abciximab
-lim-	-zu	-mab	daclizumab