Term
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Definition
bacteriostatic antibiotics chemically similar to PABA;
inhibits dihydropteroate synthetase in biosynthetic pathway of tetrahydrofolic acid;
used in combo with anti-folate drugs that inhibit dihydrofolate reductase;
most microorganisms require PABA to form dihydrofolic acid (esential source of cofactors for synthesis of thymidine, methionine, glycine, adenine, guanine;
ULTIMATELY, decreases DNA synthesis |
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Term
| Antibacterial Activity of Sulfonamides - Broad Spectrum |
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Definition
Gram (+): Staph., Strept., Bacillus, Clostridium, C. perfringens; Combo drug exhibits activity AGAINST S.aureus (MRSA);
Gram (-): Enterobacter, E.coli, Klebsiella, Proteus - increasing resistance to Gram (-)'s;
Other - Chlamydia, Toxoplasma; Resistance from spirochetes, mycoplasmas, Rickettsia; |
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Term
| Bacterial Resistance to Sulfonamides |
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Definition
limits use of these drugs as single agents;
alterations in dihydropteroate synthetase so drug cannot bind to enzyme;
N.gonorrhoaea & S.aureus overproduce PABA; |
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Term
| Bacterial Resistance to Trimethoprim |
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Definition
| involves chromosomal or plasmid-mediated expression of mutated dihydrofolate reductase; |
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Term
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Definition
poor oral absorption;
used to treat ulcerative colitis;
DON'T USE on pts w/ Sulfa allergies; |
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Term
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Definition
| bind to plasma proteins & displace other drugs bound to plasma proteins (oral anticoagulants, sulfonylurea hypoglycemic agents, hydantoin anticonvulsants) |
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Term
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Definition
decrease metabolism of drugs that are displaced from proteins --> potentiates effects/toxicities;
displaces bilirubin from protein binding sites leading to KERNICTERUS (C/I'd in children <2 months); |
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Term
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Definition
| DON'T use during 3rd trimester of pregnancy --> kernicterus |
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Term
| Hypersensitivity & Skin Rxns with Sulfonamides |
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Definition
cross-sensitization between anti-infective drugs & other drugs that contain sulfonamide group (acetazolamide, thiazides, sulfonylureas);
If allergic to these drugs, DO NOT receive topical preparations since SJS (Stevens-Johnson Syndrome) can occur;
Severe skin rxns --> rashes, angioedema, SJS, Lyell's syndrome;
Initial S/Sx: high fever, severe HA, stomatitis, conjunctivitis, rhinitis;
photosensitivity rxns |
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Term
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Definition
| sulfonamides can act as oxidants & may lead to this problem, especially in pts w/ glucose 6-phosphate dehydrogenase deficiency (G6PD); |
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Term
| renal damage caued by crystalluria |
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Definition
occurs because sulfonamides & N-acetyl liver metabolites have poor solubility in urine; older drugs cause this more commonly than newer drugs;
managed by maintaining urine output & if necessary alkalinization of urine with NaHCO3; |
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Term
| GI Side Effects of Sulfonylureas |
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Definition
nausea & vomiting;
clostridium difficile-associated pseuodomembranous colitis |
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Term
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Definition
may occur in new-born children because sulfonamides displace bilirubin from binding sites on albumin --> bilirubin enters CNS;
DO NOT use in newborns <2 months or in pregnant women at term due to this effect |
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Term
| sulfamethoxazole (Gantanol) |
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Definition
| used to treat UTIs in combo w/ trimethoprim |
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Term
| sulfasalazine (Azulfidine) |
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Definition
PKs: 10% of drug is absorbed as unchanged drug, other 90% travels to colon where drug is cleaved by intestinal flora to form sulfapyridine & 5-aminosalicylic acid (mesalamine);
Uses:
- mild to moderate ULCERATIVE COLITIS, inflammatory bowel disease; |
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Term
| silver sulfadiazine topical cream (SSD) |
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Definition
antibacterial activity of silver salt & drug does not appear to be related to inhibition of bacterial folic acid production, but has effect on cell membrane & cell wall;
Uses:
- ADJUNCT therapy for tx of infections associated w/ 2nd & 3rd degree burns;
- activity against Psuedomonas Aeruginosa |
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Term
| trimethoprim (Proloprim, Trimpex) |
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Definition
PKs: completely absorbed after oral administration;
Activity:
- Gram (+): Strep. Pneumoniae, Strep. Pyogenes, but Enterococcus is resistant;
- Gram (-): active against common gram (-) microorganisms that cause UTIs;
- NOT good anaerobic drug;
Uses:
- UTIs caused by E.coli, Proteus, Klebsiella, Enterobacter, Staph. saprophyticus; |
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Term
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Definition
rash & pruritus;
GI - N/V, elevated LFTs;
Hematological - thrombocytopenia, neutropenia, megablastic anemia, methemoglobinemia (occurs most often in folate-depleted pts [i.e. alcoholics]);
teratogen - use w/ caution in nursing mothers, or during pregnancy;
Hyperkalemia |
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Term
| leucovorin (folinic acid) |
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Definition
used to treat hematological effects (thrombocytopenia, neutropenia, megablastic anemia) in malnourished/folate-deficient pts;
Dose:
3-15 mg daily for 3 days or longer PRN |
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Term
| sulfamethoxazole + trimethoprim (Bactrim, Septra) |
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Definition
ADV: synergistic bactericidal effect observed when 2 drugs are administered together & less development of resistance;
readily absorbed from GI;
distributes to most tissues INCLUDING CSF;
long T1/2 metabolized by liver & excreted in urine by kidneys;
Uses:
- UTIs (single dose, 3-day, or 7-10 day therapy) to treat acute uncomplicated UTIs caused by E.coli, Proteus, Klebsiella, Enterobacter;
DRUG of CHOICE for EMPIRIC therapy for acute UTIs;
also used from chronic tx of recurrent UTIs;
tx pneumocystis jiroveci pneumonia for pts w/ AIDS --> causes fever, dermatological rxns, & hematological rxns |
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Term
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Definition
GI - N/V, anorexia;
Skin rxns - rash, urticaria;
occur in up to 80% of AIDS pts taking drug;
Hematological - aplastic anemia, agranulocytosis, leukopenia, neutropenia (increased risk in folate-depleted, malnourished pts |
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Term
| Pneumocystis jiroveci - pneumocystosis |
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Definition
protozoan with characteristics of fungi;
life-threatening pneumonia in immunocompromised pts;
leading cause of death in AIDS pts; |
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Term
| Preferred Drugs for Pneumocystis jiroveci pneumonia |
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Definition
1) TMP-SMX - drug of choice for acute & prophylactic treatment;
2) pentamidine isethionate - alternative for pts intolerant to TMP-SMX w/ severe pneumonia |
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Term
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Definition
IV dosage used to tx P. jiroveci infections, inhalation form used for prevention;
MoA: not well understood, DOES appear to interfere w/ synthesis of DNA, RNA, phospholipids & proteins;
- alternative to TMP-SMX for P.Jiroveci infections;
ADRs:
- hypotension;
- hypoglycemia - pancreatic islet necrosis, followed by hyperglycemia, & DM several months after therapy;
- pulmonary - bronchospasm & cough; |
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Term
| ciprofloxacin (Cipro, Cipro IV) |
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Definition
fluoroquinolone widely used, oral & IV; has better activity against gram (-) than gram (+);
Best Uses:
Best activity against Pseudomonas Aeruginosa;
tx Prostatis;
GI infections like bacterial diarrhea; |
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Term
| levofloxacin (Levaquin, oral & IV) |
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Definition
newer, better coverage against Gram (+);
Used to treat:
- LRTIs (CAP) |
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Term
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Definition
| fluoroquinlone withdrawn due to cardiovascular side effects (serious ventricular arrhythmias) |
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Term
| moxifloxacin (Avelox, oral/IV) |
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Definition
newer fluoroquinolone with better Gram (+) coverage;
Best Uses:
- LRTIs (CAP) |
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Term
| nitrofurantoin (Furadantin, Macrodantin, Macrobid) |
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Definition
- can ONLY be used to tx UTIs b/c excretion of drug is SO rapid that systemic effects are not seen;
MoA: not well understood;
Active against many Gram (+) & Gram (-) bacteria EXCEPT Proteus, Pseudomonas Aeruginosa;
Used to tx chronic UTIs (urinary tract antiseptic);
ADRs:
- GI upset (anorexia, N/V);
- rare hemolytic anemia |
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Term
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Definition
Oral, IV;
Excreted by kidney - dose-adjust in renal failure;
- does NOT penetrate CNS well, but DOES penetrate abscesses well;
MoA: binds to 50S subunit & inhibits bacterial protein synthesis;
Resitance: methylase inactivates drug, mutations in 50-S subunit;
Activity:
- Gram (+): against MOST Staph. aureus strains (NOT MRSA);
- NOT useful against Gram (-);
- active against BOTH Gram (+) & Gram (-) anaerobes (B. fragilis, C. perfringens);
Uses:
- tx anaerobic infections (abscesses);
- prophylaxis against endocarditis in pts w/ valvular heart dx having dental procedures performed;
ADRs:
- diarrhea, nausea, skin rashes;
- pseudomembranous colitis (C. difficile) |
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Term
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Definition
MoA: inhibits bacterial cell wall synthesis by binding to D-alanyl-D-alanine portion of peptidoglycan pentapeptide;
Bactericidal;
Resistance: due to bacterial enzymes that can induce alterations in cell wall precursors, can't bind as well;
Activity:
- gram (+): against MRSA, Staph. epidermidis;
- NO USEFULNESS against Gram (-);
- used for Gram (+) infections allergic to penicillins & cephs;
- enterococcal endocarditis --> w/ aminoglycoside (synergism);
- diarrhea caused by C.difficile (Pseudomembranous colitis);
ADRs:
- ototoxicity;
- nephrotoxicity;
- "red man" or "red neck" syndrome - prevent by slowing IV infusion rate; |
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Term
| polymyxin B (Aerosporin, Roerig) |
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Definition
used topically due to toxicity that is associated w/ parenteral administration;
PDs: interacting w/ cell membrane phospholipid & disrupting cell membrane permeability, causes leakage of intracellular components;
Activity: restricted to Gram (-) bacteria - Enterobacter, E.coli, Klebsiella, Bordatella, Shigella, PSEUDOMONAS AERUGINOSA;
Uses: topical tx of infections of eye, skin, mucous membranes, ear, wounds, burns (infections caused by P. aeruginosa);
ADRs: nephrotoxicity, neurotoxicity; |
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Term
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Definition
widely distributed including CNS & brain abscesses;
MoA: reduction of drug to compounds that bind to intracellular macromolecules that are bactericidal;
Activity: bactericidal activity against Anaerobes (including B. fragilis - DRUG OF CHOICE);
Uses:
- anaerobic infections (soft tissue, intra-abdominal, pelvic infections, brain abscesses);
- pseudomembranous colitis (C. difficile);
- tx of peptic ulcer dx caused by H. pylori (in combo);
ADRs: carcinogenic potential, disulfiram-like rxn w/ EtOH, peripheral neuropathy (prolonged use) |
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Term
| bacitracin (Bacitracin USP, Baci-IM) |
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Definition
opthalmic & dermatolic ointments;
MoA: inhibits cell wall formation by interfering w/ lipid that carries peptidoglycan subunits to site of cell wall formation;
Uses:
- topically for open wounds to eradicate mixed microorganisms;
- used for eye infections (conjunctivitis);
may be used in combo w/ polymyxin + neomycin
Side Effects: serious nephrotoxicity from parenteral use, renal failure; |
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Term
| quinupristin/dalfopristin (Synercid) |
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Definition
Uses: IV tx of bacteremia & other life-threatening infections caused by vancomycin-resistant Enterococcus & complicated skin infections caused by S. aureus & S. pyogenes;
MoA: similar to macrolide antibiotics, binds to 50-S ribosomal subunit, prevent extrusion of new proteins which results in bacterial cell death;
Activity:
- enterococcus faecium;
- MRSA & Staph. epidermidis;
- penicillin-susceptible & resistant Strep. Pneumonia;
Uses:
- infections caused by Staph., E. faecium, & strep. when resistant to other antibiotics; |
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Term
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Definition
MoA: bacterial protein synthesis inhbitor by binding to 50-S ribosomal subunit;
Activity & Uses:
- vancomycin-resistant E. faecium;
- nosocomial pneumonia (CAP) due to Staph. aureus or penicillin-susceptible S. pnuemonia;
- skin & skin structure infections including MRSA & strep. pyogenes;
ADRs: diarrhea, N/V, thrombocytopenia, reversible inhibitor of MAO - don't take with tyramine-rich foods (HTNsive crisis) |
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Term
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Definition
MoA: conc.-dependent killing effect by binding to & depolarizing bacterial cell membranes which leads to loss of membrane potential, K efflux, & cell death;
No known resistance mechanisms;
UNIQUE: useful for MRSA w/ vanco-resistance;
Uses:
- complicated skin & skin structure infections caused by MRSA, hemolytic strep., & vanco-susceptible E. faecalis;
DO NOT USE for PNEUMONIA - deactivated by lung surfactants; |
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Term
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Definition
well absorbed after oral administration;
T1/2 = 3-10 hrs;
Oral absorption impaired by divalent cations found in antacids;
Fe, Zn, Ca supplements decrease oral absorption - DO NOT take antacids containing Mg/Al or products containing Fe or Zn within 4 hrs before or 2 hrs after dosing;
Widely distributed to tissues --> low in CSF, HIGH in prostate (used for prostate infections);
doses adjusted for renal failure; |
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Term
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Definition
bactericidal;
works by inhibiting bacterial enzymes DNA gyrase & topoisomerase IV;
Resistance:
- mutation on DNA gyrase which prevents binding of drug --> BIG PROBLEM very rapid development, used to be very effective against MRSA;
Broad spectrum, relatively safe, but are being overused |
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Term
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Definition
Spectrum:
- gram (+) bacteria - older agents better against gram (-), newer agents (levofloxacin, moxifloxacin) better with gram (+);
Gram (-): more than 90% of enterbacteria are SUSCEPTIBLE;
Pseudomonas (cipro has best activity);
Anaerobes: NOT good activity against; |
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Term
| Clinical Uses of Fluoroquinolones |
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Definition
UTIs caused by multi-drug resistant bacteria;
Prostatis;
GI infections like bacterial diarrhea;
LRTIs (CAP - S.pneumoniae resistant to penicillins - use levofloxacin, moxifloxacin);
Useful against pneumonia & bronchitis caused by gram (-) bacteria;
NO LONGER RECOMMENDED for gonorrhea; |
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Term
| Toxicity, ADRs of Fluoroquinolones |
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Definition
Common: nausea, HA, dizziness;
CNS stimulation: seizures, psychoses - RARE (more common in people w/ CNS disorders);
Photosensitivity;
Can cause damage growing cartilage & NOT recommended in children under 18 or during pregnancy;
Adult tendinitis;
Prolongation of QT interval & torsades de pointes;
Superinfections; |
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Term
| fluoroquinolones in children <18 yrs old |
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Definition
| fluoroquinolones can ONLY be used if pts have cystic fibrosis or pseudomonal infections; |
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