Comprehensive Exam - Pharmacology Flashcards

0
Q

Cephalosporins

A

mechanism same as penicillins, more resistant to B-lactamase
Adverse effects: cross sensitivity with penicillin
Renal excretion generally

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1
Q

penicillins

A

Bind to PBPs and inhibit transpeptidase reaction and cross linking of peptidoglycans.
CSF: enter inflamed meninges.
Excretion: renal (exceptions: ampicillin, naficillin = biliary)
Adverse effects: hypersensitivity reaction (mild-severe), diarrhea, superinfections

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2
Q

Aminoglycosides

A

Bind to 30S subunit & interfere with initiation of protein synthesis. Cause incorporation of wrong amino acids.
Renally excreted
Adverse effects: Renal toxicity (reversible), Cochlear toxicity (irreversible), Vestibular toxicity (reversible)
examples: gentamicin, neomycin

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3
Q

Tetracyclines

A

block tRNA from binding to 30S subunit, preventing addition of new amino acid.
Renal excretion
Adverse effects: bind to calcifying teeth and bone, hepatotoxicity for pregnant women, nephotoxicity, phototoxicity

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4
Q

Macrolides

A

Examples: erythromycin
Bind 50S subunit, block peptidyl transferase.
Adverse effects: ototoxicity (high doses), cholestatic jaundice

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5
Q

Clindamycin

A

Binds 50S subunit.

Adverse effects: superinfection by C. difficile

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6
Q

Sulfonamides

A

Examples: sulfamethoxazole
inhibit dihydropteroate synthase, decrease folic acid
Renal excretion, cause crystaluria, displace other drugs from albumin
Adverse effect: skin rashes/ Stevens-Johnson syndrome, kernicterus in neonates

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7
Q

Trimethoprim

A

Inhibits bacterial dihydrofolate reductase

Adverse effects: cause folate deficiency in pregnant women

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8
Q

Floroquinolones

A

Examples: Ciprofloxacin
Inhibits DNA gyrase
Chelates metals, post antibiotic effect
Toxicity: CNS problems if taken with coffee, phototoxicity, arthropathy in children

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9
Q

Isoniazid

A

Inhibits synthesis of mycolic acid.
High concentration in CSF
Toxicity: hepatitis (risk is high > 50 years), peripheral neuropathy (prevented by B6)
Used for TB prophylaxis

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10
Q

Rifampin

A

Binds to DNA dependent RNA polymerase and inhibits transcription.
Toxicity: hepatitis, hypersensitivity reaction, discoloration of body fluids
Tuberculosis

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11
Q

Ethambutol

A

Blocks arabinosyl transferase (cell wall synthesis)
Enters CSF
Toxicity: optic neuritis, acute gout

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12
Q

Pyrazinamide

A

Pyrasinoic acid inhibits growth
Enters CSF
Toxicity: Acute gout

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13
Q

Chloramphenicol

A

toxicity: gray baby syndrome

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14
Q

Vancomycin

A

Red man syndrome (infusion related toxicity due to histamine release)

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15
Q

Otitis media

A

S. pnumonia, H. influenzae
Drug of choice: amoxicillin
Resistance by beta-lactamase: amoxicillin + clavulanate
If diarrhea, switch to Cefprozil (2nd gen cephalosporin)

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16
Q

Surgical prophylaxis

A

IV administation 2 hrs before surgery.
S. aureus, S. epidermis
Cephazolin (1st generation cephalosporin). Severe penicillin allergy or MRSA: Vancomycin
Colorectal & appendectomy: Add oral antibiotics as well due to increased risk of infection

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17
Q

Community Acquired Pneumonia

A

S. pneumoniae
Erythromycin
Requiring hospitalization: Erythromycin + Cefotaxime (3rd generation cephalosporin)
For neuropenic patients: levofloxacin

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18
Q

Gonorrhea

A

Ceftriaxone (3rd gen cephalosporin)

Severe penicillin allergy: Ciprofloxacin

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19
Q

Traveller’s diarrhea

A

Ciprofloxacin

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20
Q

Pseudomembranous colitis

A

Antibiotic induced diarrhea.
Cause is C. difficile.
Treat with metronidazole

21
Q

Urinary tract infections

A

Trimethoprim-Sulfamethoxazole (TMP-SMX)

Pregnant patients: Cephalexin

22
Q

Ampicillin with gentamicin

A

good synergistic effect. Ampicillin makes pores in bacterial cell wall through which aminoglycoside can enter

23
Q

Erythromycin, fungal azoles, metronidizole with Cyclosporin, or Warfarin

A

inhibit cytochrome P-450 and increase toxicity of warfarin/ cyclosporin
Excess immunosuppression, renal toxicity of CSA
Increase prothrombin time and bleeding (warfarin)

24
Q

Rifampin and isoniazid on fungal azoles, warfarin, cyclosporin

A

induce P-450 to increase the metabolism of azoles, cyclosporin, warfarin

25
Q

Sulfonamides on methotrexate, warfarin

A

sulfonamides displace drugs from albumin, increasing their toxicity

26
Q

Floroquinolones on caffeine and theophylline

A

floroquinolones inhibit microsomal enzymes (CYP1A) involved in caffeine metabolism, increasing its effects. Risk of seizures

27
Q

Floroquinolones with milk products and antiacids

A

tetracyclines & floroquinolones chelate metals (Calcium) and dairy products interfere with there absorption

28
Q

teratogenic antibiotics

A

Aminoglycosides
Tetracyclines
TMP-SMX
Fluoroquinolones

29
Q

Bactericidal antibiotics

A

Cell wall synthesis inhibitors (penicillins, cephalosporins, vancomycin)
Aminoglycosides
Fluoroquinolones
TMP-SMX

30
Q

Bacteriostatic antibiotics

A
Tetracyclines
Macrolides
Clindamycin
Sulfonamide
Trimethoprim
31
Q

Carbon Monoxide

A

Hypoxia to brain, hypoxia to heart.
High affinity binding to hemoglobin, forms carboxyhemoglobin. Competes with O2 and prevents it from binding to Hb.
Antidote: 100% O2, Hyperbaric O2 for serious cases or pregnant women

32
Q

Cyanide

A

Hypoxic symptoms; no cyanosis. Bitter almond smell, metabolic acidosis
Binds to ferric iron of cytochrome oxidase, stops electron transport.
Death due to respiratory failure
Antidote: 1. Amyl nitrate (Hb to MetHb) 2. Sodium thiosulfate (increase renal excretion) 3. methylene blue (metHb back to Hb)

33
Q

Methanol

A

(Denatured alcohol, antifreeze)
Feeling of being in a snow field, blurred vision, papilledema, abdominal pain.
Metabolized by alcohol dehydrogenase to form formic acid -> retinal damage, profound metabolic acidosis.
Antidote: ethanol, hemodialysis, bicarbonate

34
Q

Lead

A

Hypochromic microcytic anemia, encephalopathy, seizures (children), peripheral neuropathy + kidney damage (adults), abdominal pain.
Accumulates in bone, decreased heme synthesis, RBC stippling, inhibits ALA dehyratase & ferrochelatase.
Antidote: Calcium disodium EDTA, Dimercaprol, Succimer (Children), penicillamine (mild toxicity)

35
Q

Iron overdose

A

Acidosis, liver failure, GI bleeding, occurs in children.
Lipid peroxidation in mitochondria, inhibits electron transport, metabolic acidosis
Antidote: deferoxamine

36
Q

Chlorinated aromatic hydrocarbons (Dioxin)

A

chloracne, porphyria, liver damage, CNS dysfunction & impaired reproduction
induces enzymes via arylhydrocarbon receptor. Mimics estrogens.
No specific antidote: give Cholestyramine (removes bile acid needed for toxin reabsorption)

37
Q

Paraquat

A

herbicide.
Dyspnea, nonproductive cough, hypoxic symptoms, pulmonary infiltrates & lung fibrosis.
Redox cycle: converts O2 into toxic radicals which cause lipid peroxidation, cell death, inflammation.
100% oxygen is contraindicated.
Treatment: serial activated charcoal, hemoperfusion

38
Q

Warfarin & superwarfarin toxicity

A

Rat poison
GI bleeding, hematuria, epistaxis, ecchymoses, increased PT, decreased Hb
Blocks Vitamin K epoxide reductase by competing with vitamin K
Antidote: Vitamin K.

39
Q

Cyclophosphamide & allopurinol

A

Allopurinol decreases CYP-450 activity and increases the toxicity of cyclophosphamide.
therapeutic adjustment: decrease dose of cyclophosphamide

40
Q

Procarbazine and sympathomimetics or tyramine-containing foods

A

procarbazine inhibits monoamine oxidase (MAO) which results in elevation of tyramine & norepinephrine. This causes hypertension.
The patient should not eat tyramine containing foods while taking procarbazine

41
Q

procarbazine & antidepressents

A

procarbazine inhibits P-450 and potentiates sedative effects of phenothiazine, barbituates, and narcotics.

42
Q

Methotrexate & salicylate (aspirin) or sulfonamide

A

salicylate or sulfonamide displaces methotrexate from albumin and inhibits its tubular secretion, increasing toxicity.
Leucovorin is used as an antidote.

43
Q

6-mercaptopurine & allopurinol

A

allopurinol inhibits xanthine oxidase and prolongs half life of 6MP, increasing its toxicity.
Decrease the dose of 6-MP to 25%.

44
Q

Alpha 1 receptor

A

Vasoconstictor, dilates pupils

45
Q

Beta 1 receptor

A

Increases heart rate

46
Q

Beta 2 receptor

A

vasodilator/ bronchodilator

smooth muscle relaxant

47
Q

alpha 2 receptor

A

autoregulator: inhibits NT release (decrease norepinephrine)

decrease heart rate

48
Q

Norepinephrine

A

alpha-1, beta-1

49
Q

Epinephrine

A

alpha-1, beta-1, beta-2