Antibiotics Flashcards
Penicillins
Beta Lactams
MOA- Inhibit the biosynthesis of petidoglycan bacterial cell wall
Sensitivity- Effective against streptococcus (Group A and B), enterococcus, staphylococci
Aminopenicillin Sensitivity
(e. g. Ampicillin, Amoxicllin)
- beta Lactam
- Effective against strep, some enterococcus, and some staphylococci
- Combining with beta lactase inhibitor (clavulanic acid, sulbactam, tazobactam) is synergistic and broadens the spectrum against more microorganisms including: MRSA, streptococcus, E Coli, clostridium, Klebsiella Proteus, shigella, salmonella
Tetracycline and Minocycline
Class: Tetracyline
MOA: inhibit protein synthesis
Clinical use: P. acnes, some H. pylori regimens
AE: renal, hepatoxcicity, GI runs, photosensitivity, Steve-Johnsons Syndrome
Contraindications: Pregnancy class X, DO NOT use in pregnant women, lactating women, children <8 yrs.
Vancomycin
Class: Glycopeptides
MOA: inhibits cell wall synthesis
Clinical use: Used to treat serious gram-positive infections that are resistant to other antibiotics
e.g. Vancomycin IV treatment of MRSA
Oral vancomycin is used to treat C. difficile colitis
AE: Ototoxicity (transient or permanent)
Nephrotoxicity
“Red Man” syndrome if infused too fast
Contraindications:
Misc: oral absorption poor from GI, IV excreted by kidneys and PO excreted in the feces
Acyclovir
Class: Antiviral-Nucleoside Analogues
MOA: inhibit viral replication
Clinical use: active against HSV 1 and 2, varicella-zoster virus (VZV), Epstein-Barr virus (EBV), Cytomegalovirus (CMV), and herpes virus 6
AE: Headache, nausea, vomiting, skin rash, diarrhea, renal impairment
Anti-pseudomonal PCN Sensitivity
(Piperacillin, ticarcillin)
Enhanced activity against gram-negative bacilli like pseudomonas aeruginosa, enterobacter, morganella, and Providencia species
-Exist as combinations with beta-lactamase inhibitors, wider spectrum of activity
Penicillin Pharmacokinetics
- Oral PCN absorbed well orally
- excreted as unchanged meds in urine
- Renal failure have longer half life and increased risk of toxicity
PCN Adverse Reactions
- Serious immediate allergic reactions in 10% of patients
- Type I hypersensitivity reactions (anaphylaxis) occurs within 30 minutes
- Pruritic, maculopapular rash may occur 7-10 days after starting treatment with PCN, especially aminopencillin
- Rash is NOT a contraindication
- GI symptoms: diarrhea, nausea, vomiting
- bacterial or fungal overgrowth, C diff may occur
- Pregnancy category B
- Small concentrations in breast milk
PCN clinical use
- Safe for children and adults
- Otitis Media (amoxicillin)
- Sinusitis (Amoxicillin in peds, amoxicillin/clauvulnate in adults)
- Pharyngitis (GBA strep 1st line PCN)
- wound infections (amoxiclilin/clauvulnate 1st line for prophylaxis after animal bite and post op wounds)
- STI (Syphlis)
- UTI (2nd line therapy)
- pneumonia ( 2nd line)
Zanamivir
Antiviral for influenza
MOA: Inhibits neuraminidase viral enzyme, which prevents release of the virus and further propagation
Clinical use: influenza A and B, inhaled
AE: should not be given to patients with underlying respiratory disease, adverse reactions include bronchitis, cough and dyspnea
Doxycycline
Class: Tetracyline
Pregnancy class D
MOA: inhibit protein synthesis
Clinical use: first line therapy for C. trachomatis and Ureaplasma urealyticum, some H. Pylori regimens
AE: renal, hepatoxcicity, GI runs, photosensitivity, Steve-Johnsons Syndrome
Contraindications: DO NOT use in pregnant women, lactating women, children <8 yrs.
Valacyclovir
Class: Antiviral-Nucleoside Analogues
MOA: inhibit viral replication
Clinical use: converted to acyclovir after oral administration and is active against the same viruses
AE: Headache, nausea, vomiting, skin rash, diarrhea, renal impairment
***May cause thrombotic thrombocytopenia purpura (TTP) and hemolytic uremic syndrome (HUS) in immunocompromised patients
Famiciclovir
Class: Antiviral-Nucleoside Analogues
MOA: inhibit viral replication
Clinical use: active against HSV-1 and HSV-2, VZV, EBV, and hepatitis B virus
AE: Headache, dizziness, somnolence
Ganciclovir
Class: Antiviral-Nucleoside Analogues
MOA: inhibit viral replication
Clinical use: active against CMV
AE: Granulocytopenia, anemia, and thrombocytopenia
Oseltamivir (Tamiflu)
Antiviral for influenza
MOA: Inhibits neuraminidase viral enzyme, which prevents release of the virus and further propagation
Clinical use: influenza A and B, oral route
AE: N/V, skin rxns, neuropsychiatric events
Most effective when given within 48 hours of symptom onset of the flu
Zanamivir (Relenza)
Antiviral for influenza
MOA: Inhibits neuraminidase viral enzyme, which prevents release of the virus and further propagation
Clinical use: influenza A and B, inhaled
AE: skin rxns, neuropsychiatric events
Most effective when given within 48 hours of symptom onset of the flu
Cephalosporin adverse reactions
- Cross sensitivity with PCN, do not prescribe with history of PCN anaphylactic reaction
- Skin rash, arthralgia, fever, renal failure, hepatic failure, anemia, diarrhea,, superinfection, C diff
Fluconazole
Class: Azole antifungal
MOA: inhibitor of CYP450 3A4 and 2C9
*requires a loading dose, has the fewest drug interactions of all the Azoles.
AE: All of the Azoles and terbinafine have been associated with hepatotoxicity. Monitor liver fxn.
Fluoroquinolones
MOA- interferes with bacterial enzymes required for the synthesis of bacterial DNA
Well absorbed, but take on empty stomach
increasingly resistant, considered broad spectrum
Do not use for gonorrhea, uncomplicated cystitis, or TB
Ketoconozole
Class: Azole antifungal
MOA: inhibitor of CYP450 3A4
AE: All of the Azoles and terbinafine have been associated with hepatotoxicity. Multiple drug interactions due to CYP3A4 enzyme inhibition. Monitor liver fxn.
Metronidazole
Clinical use: protozoal infections by T. vaginalis, G. lamblia, and E. histolytica AND anaerobic bacterial infections, bacterial vaginosis and is one of the drugs in H. pylori treatment
AE: Leukopenia, alcohol use can cause disulfiram-like rxn
Contraindications: AVOID in 1st trimester of pregnancy, can cause cleft palate
Azithromycin
Class: Macrolides
MOA: inhibit RNA dependent protein synthesis
Clinical use: Drug of choice for CAP, chlamydia, Mycobacterium avium complex (MAC), alt. for its with penicillin allergies (gram +, gram -, atypical and intracellular organisms)
Contraindications: FDA warning of cardiac arrhythmias, risk of prolonged QT interval and tornadoes de pointes
Pregnancy category B, also safe in children
*least drug interactions of the macrocodes
Clarithromycin
Class: Macrolides
MOA: inhibit RNA dependent protein synthesis
Clinical use: Drug of choice for CAP, chlamydia, Mycobacterium avium complex (MAC), alt. for its with penicillin allergies (gram +, gram -, atypical and intracellular organisms)
Pregnancy category C
Cautions: They inhibit CYP450 enzymes, particularly CYP3A4, Increased drug levels due to interaction
e.g. most statins, warfarin, digoxin, colchicine, etc.
Erythromycin
Class: Macrolides
MOA: inhibit RNA dependent protein synthesis
Clinical use: Drug of choice for CAP, chlamydia, Mycobacterium avium complex (MAC), alt. for its with penicillin allergies (gram +, gram -, atypical and intracellular organisms)
Pregnancy category B, also safe in children
Cautions: They inhibit CYP450 enzymes, particularly CYP3A4, Increased drug levels due to interaction
e.g. most statins, warfarin, digoxin, colchicine, etc.
3rd gen Cephalosporin
- Used for broader indications
- More active against G- bacteria
- (ceftriaxone, cefotaxime ceftazidime)
- Ceftazidime- pseudomonas aeruginosa
Azithromycin
Class: Macrolides
Contraindications: FDA warning of cardiac arrhythmias, risk of prolonged QT interval and tornadoes de pointes
Pregnancy category B, also safe in children
*least drug interactions of the macrocodes
Clarithromycin
Class: Macrolides
Pregnancy category C
Cautions: They inhibit CYP450 enzymes, particularly CYP3A4, Increased drug levels due to interaction
e.g. most statins, warfarin, digoxin, colchicine, etc.
Erythromycin
Class: Macrolides
Pregnancy category B, also safe in children
Cautions: They inhibit CYP450 enzymes, particularly CYP3A4, Increased drug levels due to interaction
e.g. most statins, warfarin, digoxin, colchicine, etc.
What are some adverse rxns of the Macroclides (azithromycin, clairthromycin, erythromycin)?
Most common are GI: nausea, vomiting, abdominal pain, cramping, and diarrhea appears to be dose related Liver abnormalities (e.g. hepatitis, hepatic failure) Skin: urticaria, bullous eruptions, eczema, and Stevens-Johnson syndrome Hearing loss at high doses (which is reversible)
Trimethoprim/Sulfamethoxazole
Clinical uses: Most commonly used to treat UTI infections
Trimethoprim/sulfamethoxazole may be used to treat MRSA if susceptible in some areas
Pneumocystis jiroveci pneumonia prophylaxis and treatment
Bactrim
Clinical uses: Most commonly used to treat UTI infections, Pneumocystis jiroveci pneumonia prophylaxis and treatment
Septra
Trimethoprim/sulfonamide
Nitrofurantoin
*Pregnancy Class B
MOA: Inactivates or alters bacterial ribosomes causing inhibition of DNA synthesis, RNA synthesis, protein synthesis, cell wall synthesis, and aerobic energy metabolism.Inhibits many gram-positive cocci and gram-negative bacilli that cause UTIs.
List 6 of the clinical uses for Macroclides
- Drug of choice for community acquired pneumonia (CAP)
- Treatment for Exacerbation of Chronic Bronchitis
Patients who have COPD exacerbation with 2 of the 3 following criteria: increased sputum production, increased dyspnea, change in color of sputum - Chlamydia infection
- H. Pylori infections (clarithromycin)
- Mycobacterium avium complex (MAC)
- Alternative for patients with penicillin allergies
Cephalosporin Clinical Uses
- 1st gen- strep pharyngitis, skin infections
- Cephalexin, cefpodoxime, cefixime can be used as second line for UTI
- may be used to treat AOM when amoxicillin has failed
- Ceftriaxone and cefixime for GC/Chlamydia
- cefpodxime, cefuroxime, or parenteral ceftriaxone followed by oral cefpodxime can be used to treat community acquired pneumonia
Fluoroquinolones
MOA- interferes with bacterial enzymes required for the synthesis of bacterial DNA
Well absorbed, but take on empty stomach
Sulfonamides
MOA: Inhibits dihydrofolate synthetase which blocks the synthesis of folic acid.
Uses: Sulfonamides and trimethoprim work synergistically together. Active against gram-positive bacteria, gram-negative bacteria, and some protozoa.
AE: can cause acute hemolytic anemia in patients with G6PD deficiency
Trimethoprim
MOA: Inhibits dihyrofolic acid reductase which inhibits DNA synthesis.
Uses: Sulfonamides and trimethoprim work synergistically together. Active against gram-positive and gram-negative bacteria.
AE: blocks folic acid synthesis, so use caution in patient with folate deficiency and give folate supplement
Nitrofurantoin
MOA: Inactivates or alters bacterial ribosomes causing inhibition of DNA synthesis, RNA synthesis, protein synthesis, cell wall synthesis, and aerobic energy metabolism.
Inhibits many gram-positive cocci and gram-negative bacilli that cause UTIs.
List Drug interactions for Sulfonamides, trimethoprim, nitrofurantoin
GI: nausea, vomiting, anorexia, diarrhea, stomatitis, abdominal pain, C. difficile colitis
Skin: rashes, increased hypersensitivity reactions, photosensitivity
CNS: headache, dizziness, drowsiness
Liver: hepatitis, cholestatic jaundice
Sulfonamides can cause acute hemolytic anemia in patients with G6PD deficiency
Sulfonamides, trimethoprim, and nitrofurantoin can cause renal impairment—use with caution in patients with renal failure
Trimethoprim blocks folic acid synthesis, so use caution in patient with folate deficiency and give folate supplement
Linezolid
Class: Oxalodinone
MOA: Inhibitor of bacterial ribosomal protein synthesis
Most effective against aerobic gram-positive bacteria
Uses: Pneumonia, Complicated skin infections, Treatment of MRSA infections, Treatment of Vancomycin Resistant Enterococcus (VRE) infections, Very expensive (Use other drugs first)
AE: Diarrhea, Nausea, Headache, Myelosuppression, anemia, leukopenia, thrombocytopenia resolves when discontinue drug
Tetracyclines have activity against…
- Gram-positive bacteria
- Gram-negative bacteria
- Rickettsia (e.g. organisms that cause Rocky Mountain spotted fever, typhus)
- Spirochetes (e.g. Treponema pallidum that causes syphilis)
- Intracellular organisms (e.g. Chlamydia, Mycoplasma pneumoniae, Legionella)
Fluoroquinolones activity
- extensive activity against G- bacteria
- E coli, proteus, serrate, klebsiella, enterobacter, haemophilus, campylobacter, salmonella, shigella, neisseria gonorrhoeae
- some activity against G+
- activity against atypical organisms (chlamydia, legionella, mycoplasma species)
- Levofolaxcin and ciprofloxacin- pseudomonas aeruginosa
- Moxifloxacin- anaerobic
- Levofloxacin, mixofloxacin, and gemifloxacin more active against G+
Fluoroquinolones Adverse reactions
- Black box warning for tendonitis or tendon rupture
- GI: n/v, abdominal pain, C diff, altered taste
- Hepatic failure, renal calculi, prolonged Qt, angina, a flutter
- Pregnancy C, avoid
- Do not prescribe<18 years
Fluoroquinolones Clinical uses
- Complicated UTI, pyelonephritis, chronic bacterial prostatitis, pneumonia, chronic bronchitis, PCN resistant strep pneumonia, skin infections, bone/joint infections, complicated intra abdominal, infectious diarrhea
Fluoroquinolones Monitoring
- Patients with renal failure should have dosage adjusted
- Monitor EKG for QT prolongation
- Tendonitis or tendon rupture
Fluoroquinolone Education
- Food delays absorption
- Many drug interactions
- Full glass of water
- Stop med and notify provider for tendon tenderness
Clindamycin
- inhibit protein synthesis of the bacteria, binds to 50S subunit of bacterial ribosome to suppress the protein synthesis
- Oral is completely absorbed, not affected by food or gastric acid
- Metabolized by the liver and excreted in bile and urine
Clindamycin sensitivity
- G+ and anaerobic organisms
- Used to treat staph infections or strep for PCN allergic
- decreases toxin production from strep, staph, and Clostridium
Clindamycin adverse reactions
- GI: n/v, c diff, bitter or metallic taste
Skin: rash, erythema
Clindamycin indications
- 1st line for dental infections
- MRSA with low resistance
- 2nd line G+ cocci
- 2nd/3rd line treatment for upper and lower respiratory tract infections
- Treat infections in PCN allergic
- Pregnancy Category D
Clindamycin
- Lincosamides
- oral is completely absorbed
- G+ and anaerobic organisms
- Use for PCN allergic, dental infections, low resistance MRSA, pregnancy B
Levofloxacin
Fluoroquinolone effective against Pseudomonas aeruginosa Broad spectrum AVOID pregnancy and <18 Tendonitis/tendon rupture SJ syndrome Prolonged QT interval common
Ciprofloxacin
Fluoroquinolone effective against Pseudomonas aeruginosa Broad spectrum AVOID pregnancy and <18 Tendonitis/tendon rupture SJ syndrome Prolonged QT interval common
Moxifloxacin
Fluoroquinolone Anaerobic organisms Avoid pregnancy and <18 SJ syndrome Prolonged QT
Cephalexin
First gen Cephalosporin
G+ bacteria, MSSA, staph epidermidis, most strep
Cefazolin
First gen Cephalosporin
G+ bacteria, MSSA, staph epidermidis, most strep
Cefotetan
2nd gen cephalosporin
G+ bacteria, MSSA, staph epidermidis, most strep, Klebsiella, proteus, e coli
cefoxitin
2nd gen cephalosporin
G+ bacteria, MSSA, staph epidermidis, most strep, Klebsiella, proteus, e coli
