Rx_12.29 Flashcards
Hx pf antimalarial drug ==> fatigue, dark urine, jaundice/icterus ==> Dx?
- medication-induced hemolytic anemia due to glucose-6-phosphate dehydrogenase (G6PD) deficiency
- __G6PD recycles NADP+ to NADPH and deficiency impairs recycling of glutatione and this the inactivation of free radicals/peroxides in face of oxidative stress
- x-linked recessive condtion
Sources of oxidative stress ==> hemolytic anemia in G6PD deficient individuals
- antimalarial drugs
- antibiotics w/sulfonamides
- consumption of fava beans
- infection: e.g. hepatitis A
Presentation of G6PD deficiency
- previously healthy adult + oxidative stress ==> hemolytic anemia
- more common in African-Americans
- Sx
- fatigue
- dark urine jaundice
Zidovudine: MOA, use
- MOA: nucleoside analog ==> inhibits HIV reverse transcriptase
- prevents incorporation of viral genome into host DNA
- Use
- general propylaxis
- reduce risk of transmission to fetus during pregnancy
-“navir” drugs MOA
usually viral protease inhibitors
Dx?
hepatocellular carcinoma
Common form of spread/metastasis of hepatocellular carcinoma
- hematogenous dissemination
Cancers that spread via hematogenous dissemination + common sites of metastasis
- hepatocellular carcinoma
- renal cell carcinoma
- follicular thyroid carcinoma
- common sites:
- lung
- portal vein
- periportal nodes
- brain
- bones
Renal presentation in goodpasture sydnrome
- histology = linear PAS staining of glomerular basement membrane
- due to autoantibodies against type IV collagen
- also present @ alveoli ==> lung sx
- due to autoantibodies against type IV collagen
- rapidly progressive glomerulonephritis
- microscopic hematuria ==>
- renal failure
Most common cause of infectious mononucleosis
- Epstein-Barr Virus
- other causes of acute mono-like sx:
- cytomegalovirus
- acute HIV
Common finding on peripheral smear of individual with EBV
- large lymphocytes w/prominent nucleoli
- abnormal circulating cyctotoxic T lymphocytes
Presentation of aortic stenosis
- progressive dyspnea on exertion
- fatigue
- syncope
- angina
- low-volume late pulses
- left ventricular hypertrophy
- murmur = crescendo-decrescendo systolic murmur
Most common cause of aortic stenosis
- calcification of valve leaflets
- due to proliferative and inflammatory changes
Toxoid definition
- toxoid = modified toxin w/antigenic similarity but no toxicity
- e.g. toxoids used in vaccines
- ==> toxoid immunologicaly cross-reacts w/toxin
Presentation of tumor lysis syndrome
- result of tx of lymphomas/”bulky” cancers w/cytotoxic therapy
- ==> spilling of tumor cell contents into bloodstream
- increased uric acid ==> gout
- increased potassium ==> arrhythmias and weakness ==> sudden death
- decreased calcium
- increased phosphate
Major risk factors for hepatocellular carcinoma
- cirrhosis due to alcohol abus
- hep C or B
- positive family hx
Possible rare cause of hepatocellular carcinoma in patients from outside US
- aflatoxin
- mycotoxin produced by Aspergillus flavus
- causes liver cancer by intercalating into host DNA
- A. flavus may grow on peanuts/grains after harvesting and processing
- foods w/high levels of alfatoxin banned in the US
Major histologic feature in Niemann-Pick disease
- lipid-laden “foamy” macrophages in bone barrow
- N-P: deficiency of sphingomyelinase ==> acuumulation of sphungomyelin and cholesterol
- enzyme converts sphingomyelin to cerebroside
Common building block for fatty acids
malonyl-CoA (3 carbon unit)
Common cause of osteomylitis in IV drug users
- Pseudomonas aeruginosa
Tx of Pseudomonas aeruginosa
- ticarcillin
- category: penicillin
- MOA: cell wall synthesis inhibition
- piperacillin
- category: penicillin
- MOA: cell wall synthesis inhibition
EBV mechanism + presentation
- EBV ==> infectious mononucleosis
- signs/sx:
- fever
- pharyngitis
- posterior cervical lymphadenopathy
- circulating heterophil antibodies
- hepatosplenomegaly
- mechanism: infects B lymphocytes
- markers: IgM, B7, CD19, CD20
Lead poisoning: affected enzyme and accumulated substrate
- lead poisoning ==> inhibition of enzymes in heme synthesis pathway:
- ferrochelatase
- ALA dehydratase
- accumulated substrates:
- protoporphyrin
- delta-ALA (aminolevulinic acid)
Mechanism of aortic dissection in Marfan’s syndrome
- HTN + cystic medial necrosis ==> aortic aneurysms
- ==> rupture = aortic dissection
Amiodarone: MOA, SE
- Amiodarone = class III antiarrhythmic
- MOA = blocks potassium current ==> prolonged repolarization phase
- SE
- pulmonary fibrosis
- hepatotoxicity
- thyroid abnormalities
- can induce arrhythmias
Common cause of cholestatic hepatitis
- adverse effect of macrolides
- e.g. clarithromycin
- Azithromycin
- Erythromycin
Presentation of cholestatic hepatitis
- elevated LFTs
- slightly elevated AST/ALT
- significantly elevated alk-phos and gamma-glutamyl transpeptidase
- eleveted direct bilirubin
- jaundice/icterus
- hx: antibiotic tx (macrolides)
Macrolides: MOA
- inhibit bacterial protein synthesis by blocking translocation
- bind to 23S rRNA or 50S ribosomal subunit
- bacteriostatic
