Term
| Mechanism of Bacterial Resistance |
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Definition
1.The gram-negative cell envelope—Three cell layers (cytoplasmic membrane, thin cell wall, and outer membrane
2.Penicillinases (beta-lactamases)—Enzymes that cleave beta-lactam ring, making penicillins inactive. Synthesized by gram-positive and gram-negative bacteria.
3.Alteration of penicillin binding proteins (PBP's) |
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Term
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Definition
Narrow spectrum penicillin
Effective against gram positive (except penicillinase-producing staphylococci), some anaerobic bacteria, and spirochetes; resistance with beta-lactamase production, gram negative bacilli |
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Term
| Penicillin G Adverse Effects |
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Definition
| Allergic reactions; may get pain at site of injection; if accidentally given into peripheral nerve, get motor and sensory dysfunction or flaccidity; if use large doses of potassium penicillin G, can get hyperkalemia, neurotoxicity if blood levels too high – confusion, hallucinations. |
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Term
| Development of penicillin allergy |
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Definition
| Has to bind to a protein; called “hapten”; this combination completes antigen, which stimulates antibody formation |
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Term
| Penicillin G drug interactions |
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Definition
i. Aminoglycosides—cannot be mixed in IV or will be inactivated. Need to be administered separately.
ii. Probenecid—Delays renal excretion of penicillin
iii. Bacteriostatic antibiotics- Decreased bactericidal effects of PCN (antagonist) |
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Term
| Pharmacokinetics of Penicillin G |
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Definition
i. Different salts (potassium, procaine, and benzathine) of penicillin G
ii. Absorption—Oral administration not good since unstable in acid; IM but absorption of the different salts varies; IV when need high blood levels fast (only potassium salt for IV administration, NOT procaine or benzathine salts)
iii. Distribution—To most tissues and body fluids; without inflammation, poor penetration to meninges, joints and eye
iv. Elimination—By kidneys by active tubular secretion (90%); short half-life (30 minutes); renal excretion can be delayed with probenecid |
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Term
i. Nafcillin
ii. Oxacillin
iii. Dicloxacillin |
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Definition
III. Penicillinase Resistant Penicillins/Antistaphylococcal Penicillins
a. Narrow spectrum- used only against penicillinase-producing strains of Staph
b. Increasing problem with drug resistance: Methicillin resistant Staph aureus (MRSA) |
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Term
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Definition
| Gram positive, better gram negative coverage than penicillin G; sensitive to beta-lactamases so are ineffective against Staph aureus for most part |
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Term
| Ampicillin (Principen)is similar to: |
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Definition
| Amoxicillin (Amoxil) - which is preferred for oral administration; less diarrhea |
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Term
| Adverse effects Ampicillin (Principen) |
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Definition
| Hypersensitivity, rash, diarrhea |
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Term
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Definition
Extended-Spectrum Penicillins, Antipseudomonal Penicillins
b.Mechanism of Action: Cell wall active antibiotic; bactericidal
c.Antimicrobial Spectrum: Broad spectrum, susceptible to degradation by beta-lactamase |
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Term
| Adverse effects of Piperacillin |
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Definition
| Hypersensitivity, impaired platelet function |
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Term
| Administration and monitoring of Piperacillin |
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Definition
ii.Administration: IV- make sure not mixed with an Aminoglycoside
iii.Monitoring: Monitor for development of allergic reactions (including anaphylactic reactions). Be aware of potential for cross allergenicity. Watch for development of other adverse effects. Monitor signs and symptoms of infection to determine drug efficacy. |
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Term
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Definition
Like Piperacillin but are indicated for Pseudomonas aeruginosa;
Adverse effects (allergic reactions, sodium overload (CHF), interferes with platelet function-bleeding) |
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Term
| Penicillin combined with a Beta-lactamase Inhibitor |
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Definition
a.Extend antimicrobial spectrum of penicillin- combining a beta-lactamase inhibitor with a penicillinase-sensitive penicillin will extend spectrum of coverage
b.Sulbactam, clavulanic acid, and tazobactam inhibit activity of beta-lactamase
i.Ampicillin/sulbactam (Unasyn)
ii.Amoxicillin/clavulanate (Augmentin)- strengthens bond so cannot be cleaved
iii.Piperacillin/tazobactam (Zosyn)
iv.Ticarcillin/clavulanate (Timentin)
v.These lead to suprainfections |
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Term
| What can you not give w/ Penicillin? |
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Definition
| IV Aminoglycosides. administer seperate |
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Term
| What is the drug that delays renal excretion of penicillin and cephalosporins? |
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Definition
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Term
| What effect do bacteriostatic antibiotics have on bacteriocidal antibiotics such as the penicillins? |
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Definition
| Decreased effectiveness of bacterocidal antibiotics - antagonist. |
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Term
| Which 2 penicillins can cause platlet dysfunction? |
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Definition
| Piperacillin & Ticarcillin |
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