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NURS 406 Pharmacology Nursing 2023-2024 Exam Guide
What are the major functions of the α1 receptor? - CORRECT ANSWER--Increase vascular smooth muscle contraction, increase pupillary dilator muscle contraction (mydriasis), increase intestinal and bladder sphincter muscle contraction What are the major functions of the α2 receptor? - CORRECT ANSWER--Decrease sympathetic outflow, decrease insulin release, decrease lipolysis, increase platelet aggregation, decrease aqueous humor production What are the major functions of the β1 receptor? - CORRECT ANSWER--Increase heart rate, increase contractility, increase renin release, increase lipolysis What are the major functions of the β2 receptor? - CORRECT ANSWER--Vasodilation, bronchodilation, increase lipolysis, increase insulin release, decrease uterine tone (tocolysis), ciliary muscle relaxation, increase aqueous humor production What are the major functions of the M1 receptor? - CORRECT ANSWER--CNS, enteric nervous system What are the major functions of the M2 receptor? - CORRECT ANSWER--Decrease heart rate and contractility of atria What are the major functions of the M3 receptor? - CORRECT ANSWER--Increase exocrine gland secretions (e.g., lacrimal, salivary, gastric acid), increase gut peristalsis, increase bladder contraction, increase bronchoconstriction, pupillary sphincter muscle contraction (miosis), ciliary muscle contraction (accommodation) What are the major functions of the D1 receptor? - CORRECT ANSWER--Relaxes renal vascular smooth muscle What are the major functions of the D2 receptor? - CORRECT ANSWER--Modulates transmitter release, especially in the brain What are the major functions of the H1 receptor? - CORRECT ANSWER--Increase nasal and bronchial mucus production, increase vascular permeability, contraction of bronchioles, pruritis, pain What are the major functions of the H2 receptor? - CORRECT ANSWER--Increase gastric acid secretion What are the major functions of the V1 receptor? - CORRECT ANSWER--Increase vascular smooth muscle contraction
What are the major functions of the V2 receptor? - CORRECT ANSWER--Increase H2O permeability and reabsorption in collecting tubules of kidney (V2 is found in the "2" kidneys) What receptors are associate with Gq? - CORRECT ANSWER--H1, α1, V1, M1, and M What receptors are associated with Gs? - CORRECT ANSWER--H2, B1, B2, V2, D What receptors are associated with Gi? - CORRECT ANSWER--M2, α2, D Bethanechol - CORRECT ANSWER---Direct cholinergic agonist
- Activates bowel and bladder smooth muscle
- Used in postoperative and neurogenic ileus
- Resistant to AChE Carbachol - CORRECT ANSWER---Direct cholinergic agonist
- Carbon copy of acetylcholine
- Constricts pupils and relieves intraocular pressure in glaucoma Methacholine - CORRECT ANSWER---Direct cholinergic agonist
- Stimulates muscarinic receptors in airways when inhaled
- Used as a challenge test for diagnosis of asthma Pilocarpine - CORRECT ANSWER---Direct cholinergic agonist
- Contracts ciliary muscle of eye (open angle glaucoma), contracts pupillary sphincter (closed angle glaucoma)
- Potent stimulator of sweat, tears and saliva
- AChE resistant Donepezil - CORRECT ANSWER---Anticholinesterse - increases ACh
- Alzheimer disease Galantamine - CORRECT ANSWER---Anticholinesterse - increases ACh
- Alzheimer disease Rivastigmine - CORRECT ANSWER---Anticholinesterse - increases ACh
- Alzheimer disease Edrophonium - CORRECT ANSWER---Anticholinesterse - increases ACh
- Historically used to diagnose myasthenia gravis (MG is now diagnosed by anti-AChR Ab test. Neostigmine - CORRECT ANSWER---Anticholinesterse - increases ACh
- Used in postoperative and neurogenic ileus and urinary retention, myasthenia gravis, and postoperative reversal of neuromuscular junction blockade
Tolterodine - CORRECT ANSWER---Muscarinic antagonist
- Reduced bladder spasms and urge urinary incontinence Scopalamine - CORRECT ANSWER---Muscarinic antagonist
- Motion sickness Tetrodotoxin - CORRECT ANSWER---Poisoning can result from ingestion of poorly prepared puffer fish (exotic sushi)
- Highly potent toxin that binds fast voltage-gated Na+ channels in cardiac and nerve tissue, preventing depolarization - blocks action potential without changing resting potential (same mechanism as Lidocaine)
- Causes nausea, diarrhea, paresthesias, weakness, dizziness, loss of reflexes.
- Treatment is primarily supportive. Ciguatoxin - CORRECT ANSWER---Consumption of reef fish (e.g. barracuda, snapper, eel...)
- Causes ciguatera fish poisoning.
- Opens Na+ channels causing depolarization. Symptoms easily confused with cholinergic poisoning.
- Temperature-related dysesthesia (e.g., "cold feels hot; hot feels cold") is regarded as a specific finding of ciguatera.
- Treatment is primarily supportive. Scombroid poisoning - CORRECT ANSWER---Caused by consumption of dark-meat fish (e.g., bonito, mackerel, mahi-mahi, tuna) improperly stored at warm temperature.
- Bacterial histidine decarboxylase converts histidine to histamine. Histamine is not degraded by cooking.
- Acute-onset burning sensation of the mouth, flushing of face, erythema, urticaria, pruritus, headache. May cause anaphylaxis-like presentation (i.e., bronchospasm, angioedema, hypotension).
- Frequently misdiagnosed as allergy to fish.
- Treat supportively with antihistamines; if needed, antianaphylactics (e.g., bronchodilators, epinephrine). Albuterol - CORRECT ANSWER---β2 > β1 direct agonist
- Acute asthma Salmterol - CORRECT ANSWER---β2 > β1 direct agonist
- Long term asthma or COPD control Dobutamine - CORRECT ANSWER---β1 > β2, α direct agonist
- Uses: heart failure (HF) (inotropic > chronotropic), cardiac stress testing. Dopamine - CORRECT ANSWER---D1 = D2 > β > α direct agonist
- Uses: unstable bradycardia, HF, shock; inotropic and chronotropic α effects predominate at high doses. Epinephrine - CORRECT ANSWER---β > α direct agonist
- Uses: anaphylaxis, asthma, open-angle glaucoma; α effects predominate at high doses. Significantly stronger effect at β2-receptor than norepinephrine. Isoprterenol - CORRECT ANSWER---β1 = β2 direct agonist
- Uses: electrophysiologic evaluation of tachyarrhythmias. Can worsen ischemia Norepinephrine - CORRECT ANSWER---α1 > α2 > β1 direct agonist
- Hypotension (butrenal perfusion). Significantly weaker effect at β2-receptor than epinephrine. Phenylephrine - CORRECT ANSWER---α1 > α2 direct agonist
- Uses: hypotension (vasoconstrictor), ocular procedures (mydriatic), rhinitis (decongestant) Amphetamine - CORRECT ANSWER---Indirect general sympathetic agonist
- reuptake inhibitor; also releases stored catecholamines
- Narcolepsy, obesity, ADHD. Cocaine - CORRECT ANSWER---Indirect general sympathetic agonist
- Reuptake inhibitor
- Causes vasoconstriction and local anesthesia.
- Never give β-blockers if cocaine intoxication is suspected (can lead to unopposed α1 activation and extreme hypertension). Ephedrine - CORRECT ANSWER---Indirect general sympathetic agonist
- Releases stored catecholamines
- Nasal decongestion, urinary incontinence, hypotension. Norepinephrine vs. isoproterenol - CORRECT ANSWER---Norepinephrine increases systolic and diastolic pressures as a result of α1-mediated vasoconstriction causing increased in mean arterial pressure and reflex bradycardia. - However, isoproterenol (no longer commonly used) has little α effect but causes β2-mediated vasodilation, resulting in decreased mean arterial pressure and increased heart rate through β1 and reflex activity. Clonidine - CORRECT ANSWER---α2-agonist
- Uses: hypertensive urgency (limited situations); does not decrease renal blood flow; ADHD, Tourette syndrome
- Toxicity: CNS depression, bradycardia, hypotension, respiratory depression, miosis bα-methyldopa - CORRECT ANSWER---α2-agonist
- SVT (metoprolol, esmolol)—decrease AV conduction velocity (class II antiarrhythmic)
- Hypertension—decrease cardiac output, decrease renin secretion (due to β1-receptor blockade on JGA cells)
- HF—decrease mortality in chronic HF
- Glaucoma (timolol)—decrease secretion of aqueous humor Nonselective β-blockers - CORRECT ANSWER---Nadolol, pindolol (partial agonist), propranolol, timolol
- Mostly go from N to Z β1-selective antagonist - CORRECT ANSWER---acebutolol (partial agonist), atenolol, betaxolol, esmolol, metoprolol
- Mostly go from A to M Nonselective α- and β-antagonists - CORRECT ANSWER---Carvedilol, labetalol Nebevolol - CORRECT ANSWER---Combines cardiac-selective β1-adrenergic blockade with stimulation of β3-receptors, which activate nitric oxide synthase in the vasculature Toxicity of β-blockers - CORRECT ANSWER---Impotence, cardiovascular adverse effects (bradycardia, AV block, HF), CNS adverse effects (seizures, sedation, sleep alterations), dyslipidemia (metoprolol), and asthma/COPD exacerbations
- Avoid in cocaine users due to risk of unopposed α-adrenergic receptor agonist activity
- Despite theoretical concern of masking hypoglycemia in diabetics, benefits likely outweigh risks; not contraindicated Acetaminophen toxicity antidote - CORRECT ANSWER--N-acetylcysteine (replenishes glutathione) AChE inhibitor/organophosphate toxicity antidote - CORRECT ANSWER--Atropine > pralidoxime Amphetamines toxicity antidote - CORRECT ANSWER--NH4Cl (acidify urine) Antimuscarinic, anticholinergic agents toxicity antidote - CORRECT ANSWER-- Physostigmine salicylate, control hyperthermia Benzodiasepines toxicity antidote - CORRECT ANSWER--Flumazenil β-blocker toxicity antidote - CORRECT ANSWER--Glucagon Carbon monoxide toxicity antidote - CORRECT ANSWER--100% O2, hyperbaric O Penicillamine bCyanide toxicity antidote - CORRECT ANSWER--Nitrite + thiosulfate, hydroxocobalamin
Digitalis toxicity antidote - CORRECT ANSWER--Anti-dig Fab fragments Heparine toxicity antidote - CORRECT ANSWER--Protamine sulfate Iron toxicity antidote - CORRECT ANSWER--Deferoxamine, deferasirox Lead toxicity antidote - CORRECT ANSWER--EDTA, dimercaprol, succimer, penicillamine Mercury, arsenic, gold toxicity antidote - CORRECT ANSWER--Dimercaprol (BAL), succimer Copper, arsenic, gold toxicity antidote - CORRECT ANSWER--Penicillamine Methanol, ethylene glycol (antifreeze) toxicity antidote - CORRECT ANSWER-- Fomepizole > ethanol, dialysis Methemoglobin toxicity antidote - CORRECT ANSWER--Methylene blue, vitamin C Opioids toxicity antidote - CORRECT ANSWER--Naloxone, naltrexone Salicylates toxicity antidote - CORRECT ANSWER--NaHCO3 (alkalinize urine), dialysis TCAs toxicity antidote - CORRECT ANSWER--NaHCO3 (plasma alkalinization) tPA, streptokinase, urokinase toxicity antidote - CORRECT ANSWER--Aminocaproic acid Warfarin toxicity antidote - CORRECT ANSWER--Vitamin K (delayed effect), fresh frozen plasma (immediate) Drugs that cause coronary vasospasm - CORRECT ANSWER--Cocaine, sumatriptan, ergot alkaloids Drugs that cause cutaneous flushing - CORRECT ANSWER--Vancomycin, Adenosine, Niacin, Ca2+ channel blockers (VANC) Drugs that cause dilated cardiomyopathy - CORRECT ANSWER--Anthracyclines (e.g., doxorubicin, daunorubicin); prevent with dexrazoxane Drugs that cause Torsades de pointes - CORRECT ANSWER--Class III (e.g., sotalol) and class IA (e.g., quinidine) antiarrhythmics, macrolide antibiotics, antipsychotics, TCAs Drugs that cause adrenocortical insufficiency - CORRECT ANSWER--HPA suppression 2° to glucocorticoid withdrawal
Drugs that cause thrombotic complications - CORRECT ANSWER--OCPs, hormone replacement therapy Drugs that cause gingival hyperplasia - CORRECT ANSWER--Phenytoin, Ca2+ channel blockers, cyclosporine Drugs that cause gout - CORRECT ANSWER--Pyrazinamide, Thiazides, Furosemide, Niacin, Cyclosporine Drugs that cause myopathy - CORRECT ANSWER--Fibrates, niacin, colchicine, hydroxychloroquine, interferon-α, penicillamine, statins, glucocorticoids Drugs that cause osteoporosis - CORRECT ANSWER--Corticosteroids, heparin Drugs that cause photosensitivity - CORRECT ANSWER--Sulfonamides, Amiodarone, Tetracyclines, 5 - FU Drugs that cause Stevens-Johnson syndrome - CORRECT ANSWER--Anti-epileptic drugs (especially lamotrigine), allopurinol, sulfa drugs, penicillin Drugs that cause SLE-like syndrome - CORRECT ANSWER--Sulfa drugs, Hydralazine, Isoniazid, Procainamide, Phenytoin, Etanercept Drugs that cause teeth discoloration - CORRECT ANSWER--Tetracyclines (TETra=bad TEeTh) Drugs that cause tendonitis, tendon rupture, and cartilage damage - CORRECT ANSWER--Fluoroquinolones Drugs that cause cinchonism (symptoms are tinnitus and slight deafness, photophobia and other visual disturbances, mental dullness, depression, confusion, headache, and nausea) - CORRECT ANSWER--Quinidine, quinine Drugs that cause Parkinson-like syndrome - CORRECT ANSWER--Antipsychotics, Reserpine, Metoclopramide Drugs that cause seizures - CORRECT ANSWER--Isoniazid (vitamin B6 deficiency), Bupropion, Imipenem/cilastatin, Enflurane Drugs that cause tardive dyskinesia - CORRECT ANSWER--Antipsychotics, metoclopramide
Drugs that cause diabetes insipidus - CORRECT ANSWER--Lithium, demeclocycline Drugs that cause fanconi syndrome - CORRECT ANSWER--Expired tetracycline Drugs that cause hemorrhagic cystitis - CORRECT ANSWER--Cyclophosphamide, ifosfamide Drugs that cause interstitial nephritis - CORRECT ANSWER--Methicillin, NSAIDs, furosemide Drugs that cause SIADH - CORRECT ANSWER--Carbamazepine, Cyclophosphamide, SSRIs Drugs that cause dry cough - CORRECT ANSWER--ACE inhibitors Drugs that cause pulmonary fibrosis - CORRECT ANSWER--Bleomycin, amiodarone, methotrexate, busulfan Drugs that cause antimuscarinic reaction - CORRECT ANSWER--Atropine, TCAs, H1- blockers, antipsychotics Drugs that cause disulfiram-like reaction - CORRECT ANSWER--Metronidazole, certain cephalosporins, griseofulvin, procarbazine, 1st-generation sulfonylureas Drugs that cause nephrotoxicity/ototoxicity - CORRECT ANSWER--Aminoglycosides, vancomycin, loop diuretics, cisplatin. Cisplatin toxicity may respond to amifostine. Cytochrome P-450 inducers - CORRECT ANSWER--Chronic alcohol use, St. John's wort, Phenytoin Phenobarbital, Nevirapine, Rifampin, Griseofulvin, Carbamazepine Cytochrome P-450 substrates - CORRECT ANSWER--Anti-epileptics, Theophylline, Warfarin OCPs Cytochrome P-450 inhibitors - CORRECT ANSWER--Acute alcohol abuse, Ritonavir, Amiodarone, Cimetidine, Ketoconazole, Sulfonamides, Isoniazid (INH), Grapefruit juice, Quinidine, Macrolides, (except azithromycin) Sulfa drugs - CORRECT ANSWER--Probenecid, Furosemide, Acetazolamide, Celecoxib, Thiazides, Sulfonamide antibiotics, Sulfasalazine, Sulfonylureas. Patients with sulfa allergies may develop fever, urinary tract infection, Stevens- Johnson syndrome, hemolytic anemia, thrombocytopenia, agranulocytosis, and urticaria (hives). Symptoms range from mild to life threatening.
- azole - CORRECT ANSWER--Ergosterol synthesis inhibitor
- pril - CORRECT ANSWER--ACE inhibitor
- sartan - CORRECT ANSWER--Angiotensin-II receptor blocker
- statin - CORRECT ANSWER--HMG-CoA reductase inhibitor
- dronate - CORRECT ANSWER--Bisphosphonate
- glitazone - CORRECT ANSWER--PPAR-γ activator
- prazole - CORRECT ANSWER--Proton pump inhibitor
- prost - CORRECT ANSWER--Prostaglandin analog
- tidine - CORRECT ANSWER--H2-antagonist
- tropin - CORRECT ANSWER--Pituitary hormone
- ximab - CORRECT ANSWER--Chimeric monoclonal Ab
- zumab - CORRECT ANSWER--Humanized monoclonal Ab Penicillin G, V - CORRECT ANSWER---Prototype β-lactam antibiotics
- G=IV or IM; V=Oral administration
- Bind penicillin-binding proteins (transpeptidases).
- Block transpeptidase cross-linking of peptidoglycan in cell wall. Activate autolytic enzymes.
- Mostly used for gram-positive organisms (S. pneumoniae, S. pyogenes, Actinomyces). Also used for gram-negative cocci (mainly N. meningitidis) and spirochetes (namely T. pallidum). Bactericidal for gram-positive cocci, gram-positive rods, gram-negative cocci, and spirochetes.
- Penicillinase in bacteria (a type of β-lactamase) cleaves β-lactam ring.
- Toxicity: hypersensitivity reactions, hemolytic anemia Amoxicillin, ampicillin (aminopenicillins) - CORRECT ANSWER---Penicillinase-sensitive penicillins
- Same mechanism as penicillin (inhibits peptidoglycan cross-linking) with wider spectrum;
- Penicillinase sensitive (ombine with clavulanic acid to protect against destruction by β- lactamase)
- Use: extended-spectrum penicillin—H. influenzae, H. pylori, E. coli, Listeria monocytogenes, Proteus mirabilis, Salmonella, Shigella, enterococci.
- Toxicity: Hypersensitivity reactions; rash; pseudomembranous colitis.
- Resistance: penicillinase in bacteria (a type of β-lactamase) cleaves β-lactam ring.
Dicloxacillin, nafcillin, oxacillin - CORRECT ANSWER---Penicillinase-resistant penicillins Same mechanism as penicillin (inhibits peptidoglycan cross-linking)
- Narrow spectrum;
- Penicillinase resistant because bulky R group blocks access of β-lactamase to β- lactam ring.
- Use with S. aureus (except MRSA; resistant because of altered penicillin-binding protein target site).
- Toxicity: Hypersensitivity reactions, interstitial nephritis. Piperacillin, ticarcillin - CORRECT ANSWER---Antipseudomonals
- Same mechanism as penicillin (inhibits peptidoglycan cross-linking); extended spectrum
- Use: Pseudomonas spp. and gram-negative rods; susceptible to penicillinase; use with β-lactamase inhibitors.
- Toxicity: hypersensitivity reactions β-lactamase inhibitors - CORRECT ANSWER---Clavulanic Acid, Sulbactam, Tazobactam
- Often added to penicillin antibiotics to protect the antibiotic from destruction by β- lactamase (penicillinase). Mechanism of action of cephalosporins - CORRECT ANSWER---β-lactam drugs that inhibit cell wall synthesis but are less susceptible to penicillinases. Bactericidal.
- Organisms typically not covered by cephalosporins are LAME: Listeria, Atypicals (Chlamydia, Mycoplasma), MRSA, and Enterococci. Exception: ceftaroline covers MRSA. 1st generation cephalosporins - CORRECT ANSWER--Cefazolin, cephalexin Use: Gram- positive cocci, Proteus mirabilis, E. coli, Klebsiella pneumoniae. Cefazolin used prior to surgery to prevent S. aureus wound infections 2nd generation cephalosporins - CORRECT ANSWER---Cefoxitin, cefaclor, cefuroxime
- Use: gram-positive cocci, Haemophilus influenzae, Enterobacter aerogenes, Neisseria spp., Proteus mirabilis, E. coli, Klebsiella pneumoniae, Serratia marcescens. 3rd generation cephalosporins - CORRECT ANSWER---Ceftriaxone, cefotaxime, ceftazidime)
- Use: serious gram-negative infections resistant to other β-lactams. Ceftriaxone— meningitis, gonorrhea, disseminated lyme disease; ceftazidime—Pseudomonas 4th generation cephalosporins - CORRECT ANSWER---Cefepime
- Use: gram-negative organisms, with activity against Pseudomonas and gram-positive organisms. 5th generation cephalosporins - CORRECT ANSWER---Ceftaroline
- Severe gram-negative rod infections. Synergistic with β-lactam antibiotics.
- Neomycin for bowel surgery.
- Toxicity: Nephrotoxicity, Neuromuscular blockade, Ototoxicity (especially when used with loop diuretics). Teratogen.
- Resistance: Bacterial transferase enzymes inactivate the drug by acetylation, phosphorylation, or adenylation. Tetracyclines - CORRECT ANSWER---Tetracycline, doxycycline, minocycline
- Bacteriostatic; bind to 30S and prevent attachment of aminoacyl-tRNA; limited CNS penetration. Doxycycline is fecally eliminated and can be used in patients with renal failure. Do not take tetracyclines with milk (Ca2+), antacids (Ca2+ or Mg2+), or iron- containing preparations because divalent cations inhibit drugs' absorption in the gut.
- Clinical use: Borrelia burgdorferi, M. pneumoniae. Drugs' ability to accumulate intracellularly makes them very effective against Rickettsia and Chlamydia. Also used to treat acne.
- Toxicity: GI distress, discoloration of teeth and inhibition of bone growth in children, photosensitivity. Contraindicated in pregnancy.
- Resistance: decrease uptake or increased efflux out of bacterial cells by plasmid- encoded transport pumps. Chloramphenicol - CORRECT ANSWER---Blocks peptidyltransferase at 50S ribosomal subunit.
- Bacteriostatic.
- Use: Meningitis (Haemophilus influenzae, Neisseria meningitidis, Streptococcus pneumoniae) and Rocky Mountain spotted fever (Rickettsia rickettsii). Limited use owing to toxicities but often still used in developing countries because of low cost.
- Toxicity: anemia (dose dependent), aplastic anemia (dose independent), gray baby syndrome (in premature infants because they lack liver UDP-glucuronyl transferase).
- Resistance: plasmid-encoded acetyltransferase inactivates the drug. Clindamycin - CORRECT ANSWER---Blocks peptide transfer (translocation) at 50S ribosomal subunit. Bacteriostatic.
- Anaerobic infections (e.g., Bacteroides spp., Clostridium perfringens) in aspiration pneumonia, lung abscesses, and oral infections. Also effective against invasive group A streptococcal infection.
- Treats anaerobic infections above the diaphragm vs. metronidazole (anaerobic infections below diaphragm)
- Toxicity: pseudomembranous colitis (C. difficile - overgrowth), fever, diarrhea Linezolid - CORRECT ANSWER---Oxazolidinone
- Inhibit protein synthesis by binding to 50S subunit and preventing formation of the initiation complex.
- Gram-positive species including MRSA and VRE.
- Toxicity: Bone marrow suppression (especially thrombocytopenia), peripheral neuropathy, serotonin syndrome.
- Resistance: Point mutation of ribosomal RNA.
Macrolides - CORRECT ANSWER---Azithromycin, clarithromycin, erythromycin
- Inhibit protein synthesis by blocking translocation ("macroslides"); bind to the 23S rRNA of the 50S ribosomal subunit. Bacteriostatic.
- Atypical pneumonias (Mycoplasma, Chlamydia, Legionella), STIs (Chlamydia), gram- positive cocci (streptococcal infections in patients allergic to penicillin), and B. pertussis. Toxicity: MACRO: Gastrointestinal Motility issues, Arrhythmia caused by prolonged QT interval, acute Cholestatic hepatitis, Rash, eOsinophilia. Increases serum concentration of theophyllines, oral anticoagulants. Clarithromycin and erythromycin inhibit cytochrome P-450. Resistance: methylation of 23S rRNA-binding site prevents binding of drug. Trimethoprim - CORRECT ANSWER---Inhibits bacterial dihydrofolate reductase. Bacteriostatic.
- Used in combination with sulfonamides (trimethoprim-sulfamethoxazole [TMP- SMX]), causing sequential block of folate synthesis. Combination used for UTIs, Shigella, Salmonella, Pneumocystis jirovecii pneumonia treatment and prophylaxis, toxoplasmosis prophylaxis.
- Toxicity: megaloblastic anemia, leukopenia, granulocytopenia. (May alleviate with supplemental folinic acid). TMP Treats Marrow Poorly. Sulfonamides - CORRECT ANSWER---Sulfamethoxazole (SMX), sulfisoxazole, sulfadiazine
- Inhibit folate synthesis. Para-aminobenzoic acid (PABA) antimetabolites inhibit dihydropteroate synthase. Bacteriostatic (bactericidal when combined with trimethoprim). (Dapsone, used to treat lepromatous leprosy, is a closely related drug that also inhibits folate synthesis.)
- Gram-positives, gram-negatives, Nocardia, Chlamydia. Triple sulfas or SMX for simple UTI.
- Toxicity: Hypersensitivity reactions, hemolysis if G6PD deficient, nephrotoxicity (tubulointerstitial nephritis), photosensitivity, kernicterus in infants, displace other drugs from albumin (e.g., warfarin).
- Resistance: Altered enzyme (bacterial dihydropteroate synthase), decreased uptake, or increased PABA synthesis. Fluoroquinolones - CORRECT ANSWER---Ciprofloxacin, norfloxacin, levofloxacin, ofloxacin, moxifloxacin, gemifloxacin, enoxacin.
- Inhibit prokaryotic enzymes topoisomerase II (DNA gyrase) and topoisomerase IV. Bactericidal. Must not be taken with antacids.
- Gram-negative rods of urinary and GI tracts (including Pseudomonas), Neisseria, some gram-positive organisms. Toxicity: GI upset, superinfections, skin rashes, headache, dizziness. Less commonly, can cause leg cramps and myalgias.
- Contraindicated in pregnant women, nursing mothers, and children < 18 years old due to possible damage to cartilage. Some may prolong QT interval. May cause tendonitis or tendon rupture in people > 60 years old and in patients taking prednisone.
- Resistance: mutations reduce drug binding to RNA polymerase. Monotherapy rapidly leads to resistance. Isoniazid - CORRECT ANSWER---Decrease synthesis of mycolic acids. Bacterial catalase- peroxidase (encoded by KatG) needed to convert INH to active metabolite.
- Use in Mycobacterium tuberculosis. The only agent used as solo prophylaxis against TB.
- Toxicity: Neurotoxicity, hepatotoxicity. Pyridoxine (vitamin B6) can prevent neurotoxicity.
- Resistance: mutations leading to underexpression of KatG. Pyrazinamide - CORRECT ANSWER---Mechanism uncertain. Pyrazinamide is a prodrug that is converted to the active compound pyrazinoic acid.
- Use: Mycobacterium tuberculosis.
- Toxicity: Hyperuricemia, hepatotoxicity. Ethambutol - CORRECT ANSWER---Reduces carbohydrate polymerization of mycobacterium cell wall by blocking arabinosyltransferase.
- Use: Mycobacterium tuberculosis.
- Toxicity: optic neuropathy (red-green color blindness). High risk for endocarditis and undergoing surgical or dental procedures - CORRECT ANSWER--Amoxicillin Exposure to gonorrhea - CORRECT ANSWER--Ceftriaxone History of recurrent UTIs - CORRECT ANSWER--TMP-SMX Exposure to meningococcal infection - CORRECT ANSWER--Ceftriaxone, ciproflaxacin, or rifampin Pregnant woman carrying group B strep - CORRECT ANSWER--Penicillin G Prevention of gonococcal conjunctivitis in newborn - CORRECT ANSWER-- Erythromycin ointment Prevention of postsurgical infection due to S. aureus - CORRECT ANSWER--Cefazolin Prophylaxis of strep pharyngitis in child with prior rheumatic fever - CORRECT ANSWER--Benzanthine penicillin G or or penicillin V Exposure to syphili - CORRECT ANSWER--Benzanthine penicillin G Prophylaxis in HIV patients - CORRECT ANSWER--
Treatment of MRSA - CORRECT ANSWER--Vancomycin, daptomycin, linezolid, tigecycline, ceftaroline Treatment of Vancomycin-resistant enterococci (VRE) - CORRECT ANSWER-- Linezolid and streptogramins (quinupristin, dalfopristin). Treatment of multidrug-resistant P. aeruginosa, multidrug-resistant Acinetobacter baumannii - CORRECT ANSWER--Polymyxins B and E (colistin). Antifungal therapy (general overview) - CORRECT ANSWER-- Amphotericin B MoA - CORRECT ANSWER---Binds ergosterol (unique to fungi); forms membrane pores that allow leakage of electrolytes.
- Amphotericin "tears" holes in the fungal membrane by forming pores Aphotericin B clinical use - CORRECT ANSWER---Serious, systemic mycoses. Cryptococcus (amphotericin B with/without flucytosine for cryptococcal meningitis), Blastomyces, Coccidioides, Histoplasma, Candida, Mucor.
- Intrathecally for fungal meningitis.
- Supplement K+ and Mg2+ because of altered renal tubule permeability Amphotericin B toxicity - CORRECT ANSWER--Fever/chills ("shake and bake"), hypotension, nephrotoxicity, arrhythmias, anemia, IV phlebitis ("amphoterrible"). Hydration nephrotoxicity. Liposomal amphotericin toxicity. Nystatin MoA - CORRECT ANSWER--Same as amphotericin B. Topical use only as too toxic for systemic use. Nystatin clinical use - CORRECT ANSWER--"Swish and swallow" for oral candidiasis (thrush); topical for diaper rash or vaginal candidiasis. Flucytosine MoA - CORRECT ANSWER--Inhibits DNA and RNA biosynthesis by conversion to 5 - fluorouracil by cytosine deaminase. Flucytosine clinical use - CORRECT ANSWER--Systemic fungal infections (especially meningitis caused by Cryptococcus) in combination with amphotericin B. Flucytosine toxicity - CORRECT ANSWER--Bone marrow suppression. Name the - azoles - CORRECT ANSWER--Clotrimazole, fluconazole, itraconazole, ketoconazole, miconazole, voriconazole. Azoles MoA - CORRECT ANSWER--Inhibit fungal sterol (ergosterol) synthesis by inhibiting the cytochrome P- 450 enzyme that converts lanosterol to ergosterol.
