Abrams Chap 18 - Beta Lactam Antibacteral Agents

Monobactam

- gram - - does not cause kidney damange, hearing loss (as can aminoglycosides)

Cephalosporins

-Structurally and functionally similar to penicillins -Broad-spectrum antibiotics that can be used by most patients that are allergic to penicillin - more effective against gram- than gram+ - max concentration in liver and kidneys - reach therapeutic concentrations in most tissues except CSF

To maximize the prevention of an incisional infection, when will the nurse administer the prophylactic antibiotic therapy prescribed for a surgical client

1 hour prior to the first planned skin incision Rationale:When used perioperatively, cephalosporins should be given within 60 minutes before the first skin incision is made so the drug has time to reach therapeutic serum and tissue concentrations. It is not done as part of the surgical prep since that timing is not as specific.

Five generations of Cephalosporins

1) Cephalothin - no longer available 2) Cefotiam 3) Cephalexin 4) Cefepime 5) Ceftaroline- effective against MRSA *Higher generations are most broad spectrum *more effective against gram + gram + has wall that is easier to get to

contraindications for use of cephalosporins

1. previous anaphylactic reaction to penicillin 2. cross sensitivity low in those with delayed reactions to penicillin 3. skin rash 4. cephalosporin allergy 5. watch for GI upset/ bleeding

clinical indications for use of cephalosporins

1. surgical prophylaxis 2. treatment of infections (respiratory tract, urinary tract, skin, soft tissues, bones, joints, brain, spinal cord)

A client has been diagnosed with an infected postoperative wound, and cultures reveal methicillin-resistant Staphylococcus aureus (MRSA). The client is currently receiving intravenous ceftaroline because in vitro testing indicates susceptibility. When con

Administer the medication as prescribed and monitor for expected outcomes. Rationale: The nurse's responsibility in supporting prescribed medication therapy is to administer the medication as prescribed and to monitor for expected outcomes. Ceftaroline is an IV cephalosporin used for the treatment of community-acquired pneumonia and skin infections. It is the first cephalosporin to be considered active against resistant gram-positive organisms, such as MRSA, vancomycin-resistant S. aureus (VRSA), vancomycin-insensitive S. aureus (VISA), and heteroresistant VISA. Decreased renal function, not hepatic function, is a prescribing concern

A client diagnosed with E. coli resistant to other drugs has been prescribed imipenem-cilastatin to be given IM. When preparing the medication for administration, what information should the nurse obtain from the client?

Allergy to local lidocaine Rationale:To prepare the solution for IM injection of imipenem-cilastatin, lidocaine, a local anesthetic, is added to decrease pain. This solution is contraindicated in people allergic to this type of local anesthetic or who have severe shock or heart block

Penicillin prototype

Ampicillin

A client being treated with an oral penicillin should be encouraged to administer the medication on which schedule to best achieve a therapeutic effect? Select all that apply.

At regular intervals, Around the clock Rationale: Clients should aim to take penicillins at even intervals, preferably around the clock. These drugs are not normally taken with food.

A client receiving the first dose of IV ampicillin asks the nurse to evaluate a rash on the torso. What should be the nurse's initial response to the client's rash?

Attempt to differentiate a hypersensitivity reaction from a nonallergic ampicillin rash. Rationale:The nurse carefully assesses the characteristics of a rash, if present. It is necessary to distinguish, if possible, a hypersensitivity reaction from a nonallergic ampicillin rash. Corticosteroids are not indicated, and the infusion does not necessarily need to be stopped. The rash should be reported only after the initial assessment is completed

Pregnancy category for penicillins

B

CEPHAL

C - Creatine and BUN labs E - ethanol intolerance (3 days after last dose) P - pseudomembranous colitis (c-diff), monit. stool H - Hypersensitivity (rash, swelling, itching) A - thromboflebitis (IV can cause pain) L - lowers prothrombin (inc. risk for bleeding b/c Vit K)

Prototype of Cephalosporins

Cefazolin (Ancef)

A client being prepared for surgery has been prescribed antibiotics as prophylaxis. Which medication would the nurse anticipate being ordered?

Cephalosporin Rationale: Clinical indications for the use of cephalosporins include surgical prophylaxis and treatment of infections of the respiratory tract, skin and soft tissues, bones and joints, urinary tract, brain and spinal cord, and bloodstream (septicemia). In most infections with streptococci and staphylococci, penicillins are more effective and less expensive.

A client has been diagnosed with an infected postoperative wound, and cultures reveal methicillin-resistant S. aureus (MRSA). The client is currently receiving cephalosporins IV based on previous in vitro testing that indicated susceptibility. What is th

Contact the health care provider to discontinue cephalosporin. Rationale:In infections caused by MRSA, cephalosporins are not clinically effective, even if in vitro testing indicates susceptibility (except for the newest cephalosporin, ceftaroline). The health care provider will determine the need for additional tests or alternative anti-infectives.

A client with a complex medical history is scheduled to begin treatment with an IV cephalosporin. After the initiation of therapy, the nurse should monitor the client for which potential adverse effect of intravenous cephalosporin therapy? Select all that apply.

Diarrhea, Nausea and vomiting, Abdominal pain Rationale: Adverse effects to cefazolin and the other cephalosporins are like those of most other antibiotics: abdominal pain, diarrhea, gastritis, nausea, and vomiting. Neither oliguria nor itching is associated with adverse reactions to cephalosporin therapy

A client being treated for cellulitis with a cephalosporin asks the nurse what the essential difference is between generations of this medication. The nurse should respond to the client's question based on what fact?

Each successive generation is more effective against gram-negative microorganisms Rationale:Cephalosporins are grouped into generations by their antimicrobial properties. Each newer generation of cephalosporins has significantly greater gram-negative antimicrobial properties than the preceding generation, with decreased activity against gram-positive organisms. None of the remaining options accurately describe the concept of generations associated with medications

Aminopenicillins (ampicillin, amoxicillin)

Gram Positive: Streptococcus spp., Viridans, Enterococcus faecalis, Listeria Gram Negative: (HNPE) = H. influenzae, Neisseria spp., Proteus mirabilis, E. Coli (but a lot of resistance) drug of choice for bacterial endocarditis

Penicillins are more effective when used on infections caused by what organism?

Gram-positive bacteria

The nurse is justified in suspecting that a client who recently completed a course of ceftaroline may have been treated for what health problem?

Methicillin-resistant Staphylococcus aureus (MRSA) infection Ceftaroline is an IV cephalosporin for the treatment of community-acquired pneumonia and skin infections. It is the first cephalosporin to be considered active against resistant gram-positive organisms, such as MRSA. This drug is not indicated in the treatment of chlamydial infections, endocarditis, or encephalitis

8 A client has been diagnosed with an infected postoperative wound, and cultures reveal methicillin-susceptible Staphylococcus aureus. What medication should the nurse anticipate being prescribed for this client? Select all that apply.

Nafcillin, Dicloxacillin, Oxacillin Rationale:Penicillinase-resistant (antistaphylococcal) penicillins include three drugs (dicloxacillin, nafcillin, and oxacillin) that are the drugs of choice for methicillin-susceptible Staphylococcus aureus. These drugs are formulated to resist the penicillinases that inactivate other penicillins. Neither ampicillin nor doxycycline would be effective in treating this type of infection.

The nurse is providing education to a client who has been prescribed oral amoxicillin. The nurse will repeat teaching related to fluid intake if the client indicates that the drug can be taken with what beverage?

Orange juice Rationale:Clients should not take penicillins with orange juice or any acidic beverages because these may destroy the drug. None of the other options have a negative effect on the medicatio

A client has been diagnosed with streptococcal pharyngitis. What drug would the nurse expect to be prescribed by the health care provider?

Penicillin G Rationale:Some strains of streptococci have acquired resistance to penicillin G, although the drug is still effective in many streptococcal infections. It remains the drug of choice for the treatment of streptococcal pharyngitis; for prevention of recurrent attacks in clients who have had previous acute rheumatic fever due to group A streptococcus; and for the treatment of neurosyphilis. Aminopenicillins (e.g., amoxicillin) are the drugs of choice for prevention of bacterial endocarditis due to procedures that produce transient bacteremia. Penicillinase-resistant penicillins (e.g., dicloxacillin) are the drugs of choice for MRSA. Although first-generation cephalosporins such as cephalexin are effective against streptococci species, they are not the drugs of choice.

types of beta-lactam antibiotics

Penicillins Cephalosporins Carbapenems Monobactams

What event triggers the development of a superinfection

Proliferation of antibiotic-resistant microorganism

The nurse initiated administration of IV cefazolin with the dose ending at 13:00. When would the nurse expect the drug to reach peak effect?

Shortly after 13:00 Rationale: Cefazolin is distributed into most body tissues and crosses the placenta. The onset of action is rapid with both IV and IM administration. The drug peaks at the end of IV infusion and within 1 to 2 hours with IM injection.

How will a client's diagnosis of liver cirrhosis affect the potential use of appropriate ampicillin therapy to treat an infected pressure ulcer?

The client can safely be treated with ampicillin. Rationale:Ampicillin can be used in clients experiencing hepatic impairment, as can almost all the penicillins. No specific dosing are needed.

Indications for use of monobactam

UTI Skin Lower Respiratory Gynecologic infections Septicemia

Penicillin drugs

amoxicillin; ampicillin; penicillin G (inj., IV); penicillin V (PO, tabs. Veetids)

superinfection

an infection on top of another infection; typically caused by microorganisms that are resistant to the antibiotics used previously.

penicillin use in renal impairement

excreted primarily and rapidly in kidney's, so use caution

Prototype of Carbapenems

imipenem/cilastatin

What are beta-lactam antibacterials?

inhibit synthesis of bacterial cell by binding to protein in bacterial cell membrane causing defective cell wall that allows leakage if ICF destroying the microorganism.

What produced drug resistant straings of staph?

overuse of penicillins

Indications for use of penicillin

skin infections, otitis media, strep pharyngitis, animal bite, impetigo, gonorrhea more effective with gram+ than gram- bacterial infections caused by susceptible organisms

Contraindications for penicillin's.

· Hypersensitivity/Allergies to penicillin or cephalosporins * potential for cross-allergenicity w/ cephalosporins and carbapenems. · Caution with renal disease (lowered doses are necessary because excretion is reduced) · Caution with pregnancy/lactation (because diarrhea and superinfections may occur in the infant).

Carbapenems

•Broadest antibacterial action of any antibiotics to date •Reserved for complicated body cavity and connective tissue infections in acutely ill hospitalized patients •Must be infused over 60 minutes •May cause drug-induced seizure activity •This risk can be reduced with proper dosage. * effective for gram+ and gram-