Micro and Neuro part 2 Flashcards
Inhaled anesthetic that may cause nephrotoxicity?
–>Methoxyflurane
inhaled anesthetic that may cause seizures?
Enflurane
Most common drug used for anesthesia during endoscopy?
Midazolam (benzo, given by IV)
–>may cause amnesia; so, in case pt wakes up during procedure, won’t remember!
Which opiates may be used for general anesthesia?
–>Morphine and Fentanyl
Ketamines: (Arylcyclohexylamines)
- ->PCP analogs; can be used for anesthesia
- blocks NMDA (glutamate) receptors
- can cause bad dreams and hallucinations; generally only given to pre-pubertal kids
Drug used for rapid anesthesia induction and short procedures (drug that killed Michael Jackson)?
- ->Propofol
- aka “milk of anesthesia”, b/c high TG-content, so looks milky
- Potentiates GABA
2 classes of local anesthetic drugs:
-Mechanism of local anesthetics?
- ->Block Na+ channels
- Esters: procain, cocaine, tetracaine
- Amides: lidocaine, mepivacaine, bupivacaine
Why are local anesthetics sometimes given with epinephrine?
b/c epinephrine = vasoconstrictor –> will make sure drug stays local, doesn’t flow elsewhere!
In local anesthesia: which type of fibers get nerve blockade the fastest/first? Small vs Large, Myelinated vs Unmyelinated fibers:
- Small fibers > Large fibers
- Myelinated > Non-myelinated fibers
***Size matters more - So:
Small Myelinated > Small Unmyelinated > Large Myelinated > Large Unmyelinated
In local anesthesia, which senses are lost first/fastest?
Pain (lost first) > Temp > Touch > Pressure (lost last)
Dantrolene:
- mechansim?
- uses?
–>blocks Ca release from sarcoplasmic reticulum of skeletal muscle
- uses:
- Malignant hyperthermia (a rare side effect of inhaled anesthetics and Succinylcholine, a NM-blocking drug)
- Neuroleptic Malignant Syndrome (side effect of antipsychotic drugs)
Succinylcholine:
- class of drug?
- uses?
- mechanism?
- onset time and how long it lasts?
- toxicities?
- antidote?
- Neuromuscular-blocking drug
- Induces muscle relaxation –> used for muscle paralysis or mechanical ventilation (ie to do a tracheal intubation)
–>it’s a depolarizing neuro-muscular blocking drug; acts on nicotinic receptors to have prolonged depolarization
*Mechanism: 2 phases:
Phase 1 = Depolarizing Phase:
–>may get muscular fasciculations while fibers are getting depolarized
Phase 2 = Desensitizing phase:
–>after enough depolarization of fibers, muscle is no longer responsive to acetylcholine released by motor neurones; At this point, full neuromuscular block has been achieved
*Rapid onset (about 30 seconds); short duration (about 5-10 minutes)
- Reversal of blockade:
- Phase 1: cannot be reversed; no antidote (if give anti-cholinesterase drugs, can prolong depolarization!)
- Phase 2: can be reversed with cholinesterase inhibitors (like Neostigmine, which stimulates release of endogenous ACh)
- Toxicities:
- Hyperkalemia
- Hypercalcemia
- Malignant hyperthermia (can be treated with Dantrolene)
Depolarizing Neuromuscular-blocking drug?
–>Succinylcholine
Nondepolarizing Neuromuscular-blocking drugs:
- ->common suffix?
- ->uses?
- ->mechanism?
- ->reversal of blockade?
*all end in “-curarine, -crurium, -curonium”
(Tubocurarine, Atracurium, Mivacurium, Pancuronium, Vecuronium, Rocuronium) –> think CURRY!
- Uses: muscle relaxation–> muscle paralysis during surgery, mechanical ventilation (intubations)
- Mechanism: Competitively compete with ACh receptors (so, block ACh at NMJ)
- Reversal of blockade: Cholinesterase inhibitors (increase amount of ACh in junction to overcome competitive inhibition)–> ie Neostigmine, Endrophonium, or others.
Bromocriptine
- use?
- mechanism?
Dopamine-agonist (agonist for dopamine receptors)
–>used to treat Parkinson’s
Pramipexole
- use?
- mechanism?
Dopamine agonist; used to treat Parkinson’s
Ropinirole
- use?
- mechanism?
Dopamine agonist, used to treat Parkinson’s
Amantadine
- use?
- mechanism?
antiviral drug; can be used in Parkinson’s to increased dopamine release
L-Dopa/Carbidopa: mechanism?
Parkinson’s drugs
–>converted to dopamine in CNS (L-Dopa can cross BBB, unlike dopamine; Carbidoma prevents peripheral conversaion of L-dopa to dopamine)
Selegiline:
- use?
- mechanism?
- treatment of Parkinson’s
- mechanism:
- selective MAO type B inhibitor; prevents dopamine breakdown
Entacapone, Tolcapone:
- use?
- mechanism?
- used in treatment of Parkinson’s
- COMT inhibitors–> prevent degradation of L-Dopa, so increase dopamine availability
Benztropine
- use?
- mechanism?
- used to treat parkinsons’
- is an anti-muscarinic (anti-cholinergic) –> helps with the excess ACh in Parkinson’s; improves tremor and rigidity; but not effect on bradykinesia
Dopamine drugs: mnemonic?
“BALSA”
- Bromocriptine (agonizes dopamine receptors)
- Amantadine (increases dopamine release)
- L-Dopa (increases dopamine)
- Selegiline (prevents dopamine breakdown)
- Antimuscarinics (like Benztropine)
Memantine:
- uses?
- mechanism?
- Alzheimer drug
- NMDA (glutamate) receptor antagonist
Donepezil
- use?
- mechanism?
treatment of Alzheimers
-anti-cholinesterase
Galantamine:
- use?
- mechanism?
- Alzheimer’s
- anti-cholinesterase
Rivastigmine:
- ->can be used to treat Alzheimers
- ->anti-cholinesterase
Toxicity of Triptans?
–>Vasospasm
Galantamine:
- use?
- mechanism?
- Alzheimer’s
- anti-cholinesterase
Rivastigmine:
- ->can be used to treat Alzheimers
- ->anti-cholinesterase
Rivastigmine:
- ->can be used to treat Alzheimers
- ->anti-cholinesterase
Toxicity of Triptans?
–>Vasospasm
Toxicity of Triptans?
–>Vasospasm
Aminoglycosides: (use mnemonic)
“Mean GNATS canNOT kill anaerobes”
- Gentamicin
- Neomycin
- Amikacin
- Tobramycin
- Streptomycin
- Toxicities:
- Nephrotoxicity (esp when used with cephalosporins)
- Ototoxicity (esp when used with loop diuretics)
- Teratogenic
*Require O2 for uptake; so can’t be used to treat anaerobes
–>main clinical use is gram (-) rod infections
*Aminoglycosides are 30S ribosome/protein synthesis inhibitors
Neomycin:
–>Aminoglycoside; used for bowel surgery
Demeclocycline:
- Tetracycline
- ->ADH-blocker; can be used to treat SIADH (acts as a diuretic)
Doxycycline:
- ->Tetracycline
- fecally-eliminated, so can be used in pts with renal failure
Clinical uses of Tetracyclines:
“VACUUM THe BedRoom”
- Vibrio cholera
- Acne
- Chlamydia
- Ureaplasma Urealyticum
- Mycoplasma pneumonia
- Tularemia
- H. pylori
- Borrelia burgdorferi
- Rickettsia
Contraindication with tetracyclines?
–>Don’t take with milk, antacids, or iron-containing preparations! b/c divalent cations inhibit absorption of tetracyclines in gut
*Also, teratogenic –> don’t take during pregnancy
Treatment for atypical pneumonias (chlamydia, legionella, mycoplasma)?
–>Macrolides (Erythromycin, Azithromycin, Clarithromycin)
Toxicity of Erythromycin?
–>prolonged QT interval
Toxicity/main cause of noncompliance of Tetracyclines?
–> GI discomfort
Treatment of meningitis (H. influenza, N. meningitidis, Strep pneumonia)?
–>Chloramphenicol
Toxicities associated with Chloramphenicol:
- Aplastic anemia
- Gray baby syndrome (in preemies, b/c they lack UDP-glucuronyl transferase, so can’t get rid of bilirubin)
Treatment for anaerobic infections (Bacteroides, Clostridium perfringens) in aspiration pneumonia or lung abscesses?
–>Clindamycin
(for anaerobic infections above the diaphragm)
***toxicity = pseudomembranous colitis!
(note: use Metronidazole for anaerobic infections below the diaphragm)
TMP-SMX
cause sequential block of folate synthesis (so, block nucleotide synthesis)
- Sulfas –> block Dihyropteroate synthase
- Trimethoprim –> blocks Dihydrofolate reductase (like methotrexate!)
*TMP = “Treats Marrow Poorly” –> side effects of Trimethorpim: megaloblastic anemia, leukopenia, granulocytopenia
Fluoroquinolones mechanism:
–> inhibit DNA gyrase = Topoisomerase II
One case in which use fluoroquinolones in kids?
–>CF
Metronidazole mechanism:
- -> Damages DNA
- forms free radical toxic metabolites in the bacterial cell that damage DNA
Metronidazole uses:
“GET GAP”
- Giardia
- Entamoeba
- Trichomonas
- Gardnerella
- Anaerobes (Bacteroides, C. diff)
- H. Pylori (used with bismuth and amoxicillin (or tetracycline) for “triple therapy” against H. pylori)
Side effects of Metronidazole?
- -> Disulfiram-like rxn with alcohol (also get a disulfirum rxn when take cephalosporins with alcohol!)
- metallic taste
4 drugs used to treat Myco. TB:
- Rifampin
- Isoniazid (+ Pyridoxine/B6)
- Pyrazinamide
- Ethambutol
Dapsone:
–> treats Mycobacterium leprae
Isoniazid mechanism:
Decreases synthesis of Mycolic acids (so, specific to mycobacteria)
–> used as solo prophylaxis against TB (but not used alone in treatment of TB)
Isoniazid toxicities:
- drug-induced lupus
- P-450 inhibitor
- Hepatotoxicity
- Neurotoxicity
***Give Pyrodixine (Vitamin B6) with Isoniazid to prevent neurotoxicity and lupus side effects…
Rifampin mechanism:
–> Blocks mRNA synthesis by inhibiting DNA-dependent RNA polymerase (RNA-Polymerase inhibitor)
***Used to treat M Tb (RIPE) and for meningococcal prophylaxis (ciprofloxacin is also used for prophylaxis…)
Rifampin side effects:
- ->Orange body fluids! (not toxic, just happens)
- ->P-450 inducer
Pyrazinamide:
- use?
- mechanism?
- ->Treatment for M Tb (RIPE)
- ->inhibits mycolic acid production; effective in acidic environemnts –> acidic pH of phagolysosomes: best drug for reaching Tb organisms within macrophages!
Ethambutol:
- use?
- mechanism?
- Toxicity?
- ->treats M Tb (RIPE)
- ->decreases carbohydrate polymerization of mycobacterium (blocks enzyme)
***Toxicity: Red/Green color blindness = Optic neuropathy (Reversible!)
Prophylaxis against meningococcal infection?
- -> Ciprofloxacin (1st choice)
- -> Rifampin
prophylaxis against gonorrhea?
ceftriaxone
prophylaxis against syphilis?
penicillin G
prophylaxis in pts with recurrent UTIs?
–>TMP-SMX
prophylaxis for pts with endocarditis undergoing dental procedures?
Penicillins
Prophylaxis for HIV pt with CD4 <200? why?
- -> TMP-SMX
- -> prophylaxisx against PCP
Prophylaxis for HIV pt with CD4 < 100? why?
- -> TMP-SMX
- -> prophylaxis against PCP and Toxoplasmosis
Prophylaxis for HIV pt with CD4 < 50? why?
- -> Azithromycin
- -> prophylaxis against MAC
Amphotericin mechanism?
- -> Disrupts membrane function
- Binds ergosterol; forms pores in membrane allowing leakage of elecrolytes
Nystatin: mechanism? use?
–> like Amphotericin; binds ergosterol, forms membrane pores and causes leakage of electrolytes
- Very toxic, so only used topically
- Uses: Candidiasis
- swish-and-swallow for oral thrush
- topical for diaper rash or vaginal candidiasis
- azoles (Fluconazole, Ketoconazole, etc):
- ->Mechansim?
Inhibits egrosterol synthesis (by binding P-450 enzyme that converts lanosterol –> ergosterol)
Caspofungin:
- mechanism?
- use?
–>inhibits fungal cell wall synthesis by inhibiting synthesis of Beta-glucan
*Used to treat Invasive Aspergillosis
Terbinafine:
- mechanism?
- uses?
Inhibits fungal enzyme Squalene Epoxidase
–>indirectly blocking ergosterol synthesis
- Uses:
- toe nail fungus; other skin fungal infections
Griseofulvin:
- mecanism
- uses
- -> Interferes with fungal microtubule function; disrupts metosis; deposits in keratin-containing tissues (like nails)
- ->Treatment of Dermatophytes (like tinea, ringworm; also can be used for toe nail fungal infections)
Amantadine:
- mechanism?
- uses?
- Blocks viral penetration/uncoating (M2 protein)
- Causes release of dopamine from intact nerve terminals
- Uses:
- Influenza A (though most strains are resistant)
- Parkinson’s
Oseltamivir:
- mechanism?
- use?
- Inhibits influenza NA (Neuraminidase), decreasing release of progeny virus
- Treats influenza A and B
Zanamivir
- Inhibits influenza NA (Neuraminidase), decreasing release of progeny virus
- Treats influenza A and B
***like oseltamivir
Ribavirin:
- mechanism?
- uses?
- toxicities?
-Inhibits synthesis of guanine nucleotides by inhibiting IMP dehydrogenase
- Uses:
- RSV
- chronic hepatitis C
- Toxicity:
- hemolytic anemia
- Teratogenic
- **Only use in adults; except if severe case of RSV, can give to kids/infants… but, normally contraindicated
Acyclovir:
- mechanism?
- main uses?
Guanosine analog, so incorporates into newly replicated viral DNA, and inhibits viral DNA polymerase by chain termination
–> it’s monophosphorylated by HSV/VZV thymidine kinase
- Uses:
- HSV, VZV, EBV
Valacylcovir:
similar to Acyclovir, but better oral availability
Famciclovir:
similar to Acyclovir; but, drug of choice for herpes zoster (shingles)
Gangciclovir:
- mechanism?
- uses?
Guanosine analog; inhibits viral DNA polymerase
- Uses:
- CMV, especially in imm-compromised pts
- **#1 choice for CMV retinitis (if fails, then use foscarnet)
Foscarnet:
- mechanism?
- use?
Viral DNA polymerase inhibitor (does not require activation by a viral kinase, unlike acyclovir and gangciclovir)
- Use:
- CMV retinitis in immunocompromised pts when Gangciclovir fails
Cidofovir:
Inhibits viral DNA polymerase
–>treats CMV retinitis in imm-compromised pts
***does not require phosphorylation by viral kinase (like foscarnet; unlike acyclovir and ganciclovir)
