58 terms

AntiInfectives-Bacteriostatic & Bactericidal

Tetracyclines TCNs MOA
Bacteriostatic inhibitors of protein synthesis. Broad spectrum abx. Mechanisms of resistance-reduced drug accumulation-decreased uptake, increased ability to actively extrude TCNs, increased drug inactivation.
TCNs Uses
Rickettsial diasease, chlamydia, cholera, M.pneumoniae, Lyme disease, anthrax, H. pylori, acne!--lots of resistance so mainly used for acne.
Tetracycline-short acting, Demeclocycline-intermediate acting, doxycycline and minocycle-long acting
Absorption-food reduces absorption (except doxy and mino). Chelation with Ca++supplements, etc. caused insoluble chelates and will defecate it out without absorbing drug and infx will remain. Minimal liver metabolism. Short and intermediate TCNs elimination is renal--should not be given to pt. with renal failure, long acting via bile and is safe for pt with renal failure.
Gastrointestinal, effect on bone and teeth, superinfection--c.dif, candida, hepatotoxicity, renal toxicity, photosensitivity, vestibular toxicity, pseudotumor cerebri, diabetes insipidus.
Tetracyclines DI
Acitretin, isotretinoin--also pseudotumor cerebri risk, PCNs, oral contraceptives, Ca Mg Fe Al, Zn (except doxy)-positive cations, chelation and defecate out, don't absorb drug.
Tigecycline (Glycycline) MOA
Bacteriostatic, some bactericidal activity against some pneumonia isolates. Similar to TCNs.
Tigecycline Use
Complicated abdominal and skin infx that need broad empiric coverage, community-acquired bacterial pneumonia caused by step pneumoniae. Relatively new drug, not as much resistance as TCNs.
Tigecycline AE
Not for use in children <8 years, preg category D, N/V, pseudotumor cerebri, photosensitivty, teeth staining, pm colitis, can decrease clearance of warfarin, monitor INR.
Macrolides MOA
Bacteriostatic, broad spectrum abx, inhibits protein synthesis. Use if allergic to PCNs--great alternative to beta lactams! Mechanisms of resistance-production of a pump that exports the drug, modification of target ribosomes so that binding of the macrolide is impaired.
Macrolides Uses
Antibacterial spectrum similar to PCNs, most gram + bacteria some gram -. legionnaires disese, whooping cough, c. diptheriae, chlamydia, prophylactic tx rheumatic fever and bacterial endocarditis. New DIFIC FIDAXOMICIN--C. DIFFICILE!!preg category B!!!
Macrolides Drugs
Erythromycin, clarythromycin, azithromycin, fidaxomicin
Macrolides PK
(Except fidaxomicin which has minimal systemic absorption) absorption: food may decrease absorption, distribution: widely distributed except CSF. METABOLISM LIVER 3A4--erythromycins (worst offenders DDI)>clarithromycin DDI>azithromycin (least DDI). Excretion bile and urine. Pregnancy Category B, except clarithromycin is C.
Macrolides AE
GI, distorted/metallic taste (clarithromycin), suprainfection (c.dif), QT prolongation (torsades de pointes, sudden cardiac death)--erythromycins > clarithromycin > azithromycin. Ototoxicity.
Fidaxomicin-N/V abdominal pain, GI hemorrhage, neutropenia, anemia.
Macrolides DI
Antidysrhythmic drugs, digoxin, epleronone, phenothiazines, pimozide, ranolazine. CI drugs that increase QT prolongation and cardiac arrythmias.
CYP3A4 inhibitors--azole antifungals, HIV protease inhibitors.
CYP3A4 substrates--eletriptan, ergot alkaloids, statins, theophylline, carbamazepine, valproate, phenytoin, warfarin.
Telithromycin, bactericidal, broad spectrum abx inhibits protein synthesis, 2 different binding sites so active against macrolide resistant strains.
Ketolide Uses
although active against a number of organisms its use tends to be limited to Strep. Pneumonia strains that are resistant to PCNs and macrolides
Ketolides AE
Adverse reactions similar to macrolides, also hepatotoxicity, visual disturbances, CI in pt. with myasthenia gravis
Ketolides DI
CI in pt with QT prolongation or with drugs that can increase this risk. Telithromycin is both a substrate and inhibitor of CYP3A4 therefore drugs that are substrates, inhibitors, inducers will cause potential drug interactions. Same as macrolide drug interactions, but more pronounced with ketolides.
Clindamycin MOA
Primarily bacteriostatic, inhibits protein synthesis, broad spectrum abx. Mechanism of Resistance is alteration of protein binding sites.
Clindamycin Use
Most anaerobes (+/-) and gram + aerobes, pelvic infection, severe group A streptococcal infx, gas gangrene, atypical coverage includes PCP pneumonia and toxoplasmosis in HIV pt, also malarial infx
Clindamycin PK
No CSF penetration, does not penetrate into synovial fluid and bone. Primarily metabolized by the liver. Common uses include BV, skin infection, and acne.
Clindamycin AE
PM Colitis, diarrhea, hypersensitivity rash, hepatoxicity, blood dyscracias, IV infusion reactions.
Clindamycin DI
Oral contraceptives, mycophenolate mofetil
Linezolid (Oxazolidinones) MOA
Bacteriostatic/Bactericidal, broad spectrum abx, inhibits bacterial protein synthesis by interfering with translation.
Linezolid (Oxazolidinones) Use
Although active against a number of aerobic and facultative gram + bacteria it is typically reserved for use the MDR strains. ACTIVE AGAINST MDR PATHOGENS, VRE, MRSA. Bacteriostatic against stpah and enterococci, bacteriocidal against strep. Low resistance and does not appear to be cross resistant with other abx classes.
Linezolid (Oxazolidinones) AE
N/V, diarrhea, HA, PM colitis, abdominal pain, fever, REVERSIBLE MYELOSUPPRESSION-BLOOD LEVELS CHANGE, WATCH H&H, RBCS, optic neuropathy/visual loss.
Linezolid DI
Bupropion, triptans, TCA, SSRI, SNRI, MAOI, tramadol, sympathomimetic amines, foods containing tyramine (bananas)--too much norepinephrine, tachycardia, hypertensive crisis.
Dalforpristin/Quinupristin (strepogramins) MOA
Each individual agent is bacteriostatic, combo of agents is bactericidal, broad spectrum, inhibits protein synthesis by interfering with translation.
Dalforpristin/Quinupristin (strepogramins) Uses
Vancomycin Resistant E. faecium, MRSA, MRSE, MDR Strep. pneumoniae--safe for pt. allergic to PCNs/cephalosporins
Dalforpristin Quinupristin AE
HEPATOXICITY, HYPERBILIRUBINEMIA, infusion related thrombophlebitis, N/V, diarrhea, muscle pain, rash
Dalforpristin/Quinupristin DI
3A4 substrates--e.g. cyclosporins, tacrolimis, MMF, ranolazine, statins, etc.
Broad spectrum abx, ONLY FOR LIFE THREATENING INFECTIONS for which safer drugs are ineffective or contradindicated.
Chloramphenicol MOA
Distributed in CSF useful in treating meningitis and brain abscesses. Hepatically metabolized/excreted.
Chloramphenicol AE
CBC blooding monitoring is necessary, BLACK BOX-serious blood dyscrasias, bone marrow depression, aplastic anemia (can be fatal), gray baby syndrome, GI effects, peripheral neuropathy. NO BABIES OR PREGNANT WOMEN.
Chloramphenicol DI
inhibits metabolism of phenytoin, warfarin, hypoglycemic agents
Aminoglycosides MOA
Narrow spectrum abx, microbial resistance--production of enzymes that inactivate AGs, AGs are inactive against most gram (+) bacteria unless used in combo therapy
Aminoglycosides Uses
Aerobic gram - bacilli, principal use is parenteral administration b/c crosses membranes poorly.
Aminoglycosides PK
Absorption cross membranes poorly, distribution limited largely to ECF, entry into CSF is insufficient to tx meningitis, bind to renal tissue, penetrate inner ear, CROSS PLACENTA-PREG CATEGORY D, renal excretion.
Aminoglycosides Considerations
Interpatient variability, dosing scedules, narrow therapeutic index drugs--monitoring serum drug levels, AGs can be combined with other abx to treat serious infections caused by gram + cocci, can be mixed with vanco, cephalosporin, PCN (but not in same IV solution)
Aminoglycosides AE
Nephrotoxicity, ototoxicity, hypersensitivity reactions, neuromuscular blockade-can inhibit neuromuscular transmission--stop breathing!!
Aminoglycosides DI
PCNs, Cephalosporins and Vanco, Ototoxic drugs, nephrotoxic drugs, skeletal muscle relaxants.
Aminoglycosides Drugs
Tobramycin, Amikacin, Neomycin, Gentamicin, Kanamycin, Streptomycin, Paromomycin
Sulfamethoxazole-SMZ, sulfisoxazole, sulfadiazine. Bacteriostatic, broad spectrum abx, suppress bacterial growth by inhibiting dihydropteroate synthetase and ultimately folic acid.
Trimethoprim-bacteriostatic/bacteriocidal, broad spectrum, suppress bacterial growth by inhibiting dihydrofoloate reductase and ultimately folic acid.
Gram + cocci, MRSA, gram - bacilli,
Gram - bacilli, some gram + bacilli
Sulfonamides AE/DI
Hypersensitivity-rash, photosensitivity, Stevens-Johnson syndrome, Hematologic effects, kernicterus, not recommended during preg or lactation, crystalluria. Can increase warfarin, phenytoin, and sulfonylurea type oral hypoglycemics, oral contraceptives, methotrexate
Trimethoprim AE/DI
Hematologic effects, not recommended during pregnancy or lactation, can decrease urinary potassium excretion.Oral contraceptives, methotrexate, drugs that increase K+.
TMP-SMZ combo inhibits sequential steps in bacterial folic acid synthesis, making it much more powerful than TMP or SMZ alone. Uses uncomplicated UTI, pneumocystis carinii, GI infections, otitis media, bronchitis.
Quinolones MOA
Broad spectrum abx, bactericidal, inhibits bacterial DNA gyrase. Weak gram + activity, limited enterococci and poor anaerobic activity, atypical bacteria coverage legionella, chlamydia, mycoplasma, TB, anthrax
Quinolones Uses
Drug of choice for anthrax, STD, travelers diarrhea, UTI
Quinolones PK
well absorbed orally, avoid + cations, penetrate into bone (do not use in children), great urinary concentration.
Quinolones AE
GI, HA, dizziness, diarrhea, phototoxicity, slight prolongation of QT interval, risk of tendonitis and tendon rupture, nephrotoxicity and hepatotoxicity, potential exacerbation of myasthenia gravis. NOT RECOMMENDED IN PREGNANCY, BREASTFEEDING, OR CHILDREN.
Quinolones DI
+cations, milk/dairy, sucralfate, theophylline, warfarin, drugs than can cause QT prolongation-antidysrhythmic drugs, ranolazine, macrolides, drugs that can increase K+.
Quinolones Drugs
Cirpofloxacin, Levofloxacin, Ofloxacin, Norfloxacin, Gemifloxacin, Moxifloxacin
Metronidazole MOA
Alteration of organism DNA helical structure inhibiting nucleic acid synthesis, bactericidal. Spectrum of activity great for all anaerobes-C. DIF!, good atypical coverage, does penetrate the CSF, hepatically metabolized.
Metronidazole AE/DI
neurotoxicity, allergy, superinfections-yeast, GI, N/V/D, metallic taste, Seizure-caution with pt. w/neuro disorders. CI in breast feeding. Warfarin--increased anticoagulant effect, alcohol-disulfuram reaction, phenytoin-increased concentrations, lithium-increased concentrations.