Antibiotics and Antifungals

The girls are fiiiightiiinnnggg !!!! (Girls = Bacteria and the antibiotics)

What properties make antibiotics selectively toxic and effective for treatment?

Selectively toxic —> Only affects bacteria, minimal harm to host.

• Disrupts bacterial wall wall (promotes bacterial lysis)

• Inhibits bacterial production of folic acid by targeting enzymes

• Disrupts bacterial protein synthesis

Narrow vs Broad spectrum antibiotics?

Narrow = Active against only a few species of bacteria. Very specific effects.

Broad = Active against a wide variety of microbes. Resistance tends to happen more with broad spectrum antibiotics.

Does antibiotic resistance typically happen more often with broad or narrow spectrum antibiotics?

Broad!

What are the 2 ways a bacteria can be resistant to antibiotics?

• Innate (bacteria are inherently resistant)

• Can be acquired over time

  • Loss of drug sensitivity

  • Can develop in response to several drugs

What is Antimicrobial Stewardship?

Healthcare practice to prescribe and use antimicrobials appropriately to prevent the development of resistance.

How is an antibiotic selected for treatment?

1. Identify the infecting organism (MUST be completed PRIOR to starting drug therapy!)

2. Determine if microbe is resistant to drugs (not always necessary)

3. Status of host defenses and whether drug can reach the infection site

What are the different methods used to identify what organism is causing an infection?

• Gram-stain (body fluid is specifically analyzed and tested)

• PCR (Can be used even when small amount of organism is present. More specific)

What must be considered when choosing an antibiotic for a patient?

• Allergies!

• Inability of drug to reach the infection site (ex: abscesses have no blood supply, purulent drainage makes it harder)

• Risk of “First-choice drug toxicity” (there are literally no definitions for this :/ )

T/F

If a patient has a fever of unknown origin, it is recommended to treat this with a broad spectrum antibiotic.

FALSE.

Treating a fever of unknown origin with antibiotics is a misuse.

Which type of bacteria are notoriously more harmful and difficult to treat?

Gram negative bacteria.

For a patient who has an infection, what should a nurse assess for?

• Vitals

• Appearance of wound (if any)

• Sputum presence, appearance, amount

• Urine and stool (if applicable)

• WBC throughout therapy

• Signs of anaphylaxis after medication administration

• Bowel function and signs of CDAD

If a patient is exhibiting signs of anaphylaxis after administering treatment, what is the appropriate response by the nurse?

• Discontinue drug IMMEDIATELY

• Get help!

  • If in patient —> Call rapid response team!

  • If outpatient —> Call 911!

• Patient will likely need epinephrine and antihistamine

What is a superinfection?

An infection that develops while getting treated for another infection, especially when caused by agents that are more resistant to treatment.

What are the possible signs of the development of a superinfection?

• Black furry tongue overgrowth

• Vaginal itching/discharge

• Loose/foul smelling stools

What family of antibiotics affect contraceptives?

Rifampacin

How are antibiotics classified?

• Mechanism of action

  • Ex: Inhibitors of cell wall synthesis

• Susceptibility of organisms

  • Narrow spectrum gram-neg aerobes

What class of antibiotics exhibits a cross-hypersensitivity to penicillin? What does this mean, and why does this occur?

Cephalosporins

Has a similar structure to penicillins. If a patient has a penicillin hypersensitivity reaction, then they will likely have a reaction if given a cephalosporin.

THEREFORE, a penicillin hypersensitivity/allergy is contraindicated in the use of a cephalosporin.

What are the adverse drug reactions of narrow spectrum penicillins?

• GI symptoms (nausea, vomiting, diarrhea)

• Allergic reactions (rash, urticaria)

  • This drug is the most common cause of a medication allergy!

  • High risk for anaphylactic shock if allergic!

• Past anaphylactic reaction —> Risk for cross-sensitivity with cephalosporins

When administering a narrow spectrum penicillin to a patient, what characteristics should you observe for that indicates an immediate hypersensitivity reaction?

• Occurs within 20 minutes

• Symptoms = Anaphylaxis!

  • Urticaria

  • Pruritis

  • Edema

  • Laryngospasms

  • Hypotension

  • Bronchospasms

  • Vascular collapse

  • Worst case = death

T/F

When administering a narrow spectrum penicillin medication, such as PCN G, to a patient, if a patient does not exhibit hypersensitivity within 20 minutes, then they will have no reaction in the future.

False.

Delayed hypersensitivity reactions to penicillin, while rare, do occur.

• Occur 1-2 weeks after treatment

• Symptoms:

  • Fever

  • Malaise

  • Urticaria

  • Myalgia and arthralgia

  • Abd pain

  • Skin rashes

What are the most common side effects associated with ampicillin?

• Rash (can be allergic or non-allergic)

• Diarrhea

What is the most common adverse drug reaction to Piperacillin?

Bleeding due to disruption of platelet count

What are the known drug interactions that occur with ceftriaxone?

• Must not give calcium-containing drugs

• Warfarin —> INC risk of bleeding

You have received an order to administer Imipenem to a patient who has a seizure disorder. What is the correct nursing action?

Check the patient’s current medications.

If the patient is taking valproate (anti-seizure), then imipenem can reduce valproate serum levels. —> Reduces effectiveness, results in breakthrough seizures.

When administering a sulfonamide to a patient, what drug interactions are important to keep in mind?

• Inhibits liver metabolism —> Intensifies effects of…

  • Warfarin = bleeding

  • Phenytoin

  • Sulfonylurea oral hypoglycemics

• Cross-hypersensitivity to sulfites may occur

What foods interact with cirpofloxacin?

• Reduced absorption with Cation compounds

  • Antacids w/ aluminum/magnesium

  • Salts w/ iron or zinc

  • Calcium supplements or dairy

What drug interactions occur with ciprofloxacin?

• Increased plasma levels with

  • Theophylline

  • Warfarin

  • Tinidazole

What drug interactions occur with metronidazole?

• Increases levels of

  • Phenytoin

  • Lithium (toxicity! range is 0.6-1.2)

  • Warfarin (bleeding!)

• Disulfiram-like reaction

  • Alcohol

• QT interval prolongation

T/F

Amphotericin B is a very safe medication to give due to its low reactivity and low toxicity.

FALSE.

This medication is highly toxic. Remember, this is an antifungal. Common adverse effects are:

• Cardiopulmonary (tachy and hypotension)

• N/V/D

• Increased liver enzymes, hyperbilirubinemia

• Nephrotoxic (need BUN and creatinine regularly monitored)

• Phlebitis!

When administering amphotericin B to a patient, what is important to continuously monitor for the patient?

• Thrombophlebitis/infusion reactions

  • Monitor IV site, assess patency before administration

• Renal toxicity in majority of patients

  • Temporary or permanent kidney damage

  • Monitor BUN and creatinine

What medication class, when administered with penicillins, have a high risk of cross-sensitivity?

Cephalosporins. Have a similar structure.

What narrow spectrum penicillins are highly resistant to beta-lactamase inactivation?

• Nafcillin

• Oxacillin

• Dicloxacillin

In what circumstances is it not appropriate to administer nafcillin, oxacillin, or Dicloxacillin?

If the patient has had previous reactions to penicillin, carbapenems, cephalosporins, or other beta lactam antibiotics.

How many generations of cephalosporins are there?

5

Which generation of cephalosporins are best for resistant organisms?

4th and 5th.

Which generation of cephalosporins are least effective against resistant organisms?

1st gen.

How do later generations of cephalosporins differ from earlier generations?

• Increasing activity against gram neg bacteria and anaerobes

• Increasing resistance to destruction of beta-lactamases = Increased effectiveness against bacteria that are resistant

• Increased ability to reach the cerebrospinal fluid

What medications are 1st generation Cephalosporins?

“Fa/Pha” in the middle

• Cefazolin

• Cefadroxil

• Cephalexin

• Cephalothin

• Cephapirin

• Cephradine

What medications are 2nd generation Cephalosporins?

“Everything else.” Have no specific way to memorize lol.

• Cefoxitin

• Cefotetan

• Cefmetazole

• Cefprozil

What medications are 3rd generation Cephalosporins?

“One/Ten/Ime” at the end.

• Ceftriaxone

• Ceftibuten

• Cefotaxime

• Ceftazidime

• Cefpodoxime

• Cefixime

What medications are 4th generation Cephalosporins?

“Pi” in the middle

• Cefepime

• Cefpirome

What medications are 5th generation Cephalosporins?

“Rol” in the middle

• Ceftaroline

• Ceftobiprole

What antibiotics weaken the bacterial cell wall?

• Beta-lactams

  • Penicillins

  • Cephalosporins

  • Carbapenems

• Vancomycin

(Others that weren’t reviewed)

• Telavancin

• Aztreonam

• Fosfomycin

What are the narrow spectrum penicillin drugs?

• PCN G, V, or VK

• Penicillins that are resistant to beta-lactamase inactivation

  • Nafcillin

  • Oxacillin

  • Dicloxacillin

What are the broad spectrum penicillin drugs?

• Ampicillin

• Amoxicillin

• Piperacillin

Are cephalosporins broad spectrum or narrow spectrum?

Broad

What medications does carbapenem include?

-penem’s

• Imipenem

• Meropenem

• Ertapenem

• Doripenem

What is the most widely used antibiotic in hospitals? What is it typically used for?

Vancomycin.

ONLY for gram-positive organisms and serious infections.

• MRSA

• C.diff

What is the mechanism of action for vancomycin?

• Inhibits cell wall synthesis

• Promotes bacterial lysis and death

Describe the pharmacokinetics of vancomycin?

• Oral administration — Poor absorption

  • Bad for systemic infections, but useful for c.diff treatment

• IV administration — Most common

  • Eliminated through kidneys

  • If renal impairment — Decreased dosing!

Is vancomycin used in patients with renal impairment?

It can be. However, dosing will be reduced.

Generally, vacncomycin normally produces renal impairment, and renal values must always be closely monitored.

However, for patients with serious infections, the benefit may outweigh the risk.

What are the adverse effects of vancomycin?

• Renal impairment

• Ototoxicity

• Phlebitis

Pixorize: A mom is driving a van, yelling at her kid which hurts his ears, which makes him drop his kidney beans, which makes him turn red

What is the therapeutic level for vancomycin?

10-20

What are important nursing considerations in regards to vancomycin?

• Levels = 10-20

• Monitor IV site closely for phlebitis (necrosis, pain, extravasation)

• Monitor renal function (bun and creatinine), urine, I/O

• Monitor for presence of superinfections

• Monitor patients ear function and balance (8th CN)

What drug classes are bacteriostatic inhibtors of protein synthesis?

• Tetracyclines

• Macrolides

• Aminoglycosides

Are tetracyclines broad spectrum or narrow spectrum?

Broad

Are macrolides broad spectrum or narrow spectrum?

Broad

What medications do macrolides include?

“-thromycin”

Ezithromycin, clarithromycin, and azithromycin

Are aminoglycosides broad spectrum or narrow spectrum?

• Narrow spectrum

  • Primarily affects gram neg

What drug classes are considered to be antifungal agents?

• Polyene antibiotics

• Azoles

• Echinocandins

• Pyrimidine analogs

What drug classes are considered beta-lactam antibiotics? What type of bacteria do they typically affect?

“Weaken the cell wall”

• Penicillins (+)

• Cephalosporins (+/-)

• Carbapenems (+/-)

How do beta-lactam antibiotics work? How can resistance occur?

• Attack the cell wall of bacteria

• Beta-lactam inhibits Transpeptidase PBP, which is necessary for production/structure of bacterial cell wall

• 2 ways that Resistance occurs

  • Change in transpeptidase PBP structure

  • Bacteria produces beta-lactamase which breaksdown beta-lactam

What medication class is ciprofloxacin?

Fluroquinolone (antibiotic)

End with “-floxacin”

When administering ciprofloxacin, what are the adverse effects to monitor for?

• Aortic aneurysm

• Photosensitivity

• Rash

• Hepatotoxicity

• C-diff

• Abd pain

• Arthralgia

• Myalgia

• Tendonitis, tendon rupture

• CNS agitation

Pixorize:

Woman gardening her flowers with flox in her hand. Her iron gardening shears fall and slice her tendon, she gets a sunburn, and everything on her table falls to the ground, including her tums, milk, and jumbled pills.

What are the blackbox warnings for ciprofloxacin?

• Tendon rupture

• Myasthenia gravis (can exacerbate muscle weakness)

What adverse drug reactions are associated with cephalosporins?

• C-diff

• Diarrhea

• IM site pain

• IV site phlebitis

• Inc risk of bleeding

Less common

• Overall altered WBCs and platelets

  • INC eosinophils

  • DEC neutrophils

  • INC lymphocytes

  • INC or DEC platelet count

What is amphotericin B?

Antifungal (class = polyene antibiotic)

Best for systemic fungi, but highly toxic

What are the adverse effects associated with amphotericin B?

• Chest pain

• Hypotension

• N/v/d

• Hyperbilirubinemia, increased liver enzymes

• Reduced potassium and magnesium

• Nephrotocity

• Phlebitis

What is fluconazole?

Antifungal (azole)

Often used for candidiasis, UTIs, opportunistic fungi infections

What adverse effects are associated with fluconazole?

• QT interval prolongation

• SJS

  • Monitor for rash

• Hepatotoxicity

• N/V/S

Expected range of platelets

between 150-400 thousand

(a restaurant has at least 150 plates, but 400 is too many!)

Expected potassium range

3.5-5

(3 to 5 bananas in a bunch, half off)

Expected creatinine range

0.6-1.2

(high creatinine = kidney toxicity/failure!)

(Nine is right in the middle)

Expected BUN range

5-20

(5 fingers/toes, 20 total)

Are tetracyclines broad spectrum or narrow spectrum?

Broad

What are tetracyclines?

Antibiotics — Bacteriostatic inhibitors of protein synthesis

Suppress bacterial growth (don’t directly kill! Bacteriostatic)

What medications are included in tetracyclines?

“-cycline”

• They all end in cycline, all have similar structure/mechanism

• Tetracycline, demeclocycline, doxycycline, eravacycline, eravacycline, omadacycline, sarecycline, & minocycline

What are the contraindications for the use of tetracyclines? Why?

Children younger than 8 and OB-gyn patients.

Results in permanent teeth staining and decreased long bone growth, teratogenic.

Pixorize - Tetracycline adverse effects!

Young boy falls of his bicycle after getting scared by a tarantula, gets dirt in his teeth, gets a sunburn, drops his kidney beans, and hurts his belly.

His mom is calling him and asking him to take tums and milk, but he is refusing.

• Teratogen, shouldnt be used in children or OB

  • Teeth staining

• GI symptoms and liver toxicity

• Nephrotoxicity

• Photosensitivity

• Don’t take with calcium (or iron or any other cation), antacids

What is often the cause of UTIs?

E.coli

Then s. saprophyticus, and enterococcus

What are the signs and symptoms of a UTI?

• Dysuria

• Urinary urgency

• Urinary frequency

• Suprapubic discomfort

• Pyuria

• Bacteriuria

What medications are the first line treatment for UTIs?

Sulfamethoxazole and Trimethoprim (can be individual or combined)

Nitrofurantoin

What is the mechanism of action for sulfonamide and trimethoprim preparations?

For UTIs

• Inhibits synthesis of folate

• Bacteria will be unable to synthesize DNA, RNA, and proteins

What adverse effects are associated with sulfonamides?

• Hypersensitivity (fever, SJS, photosensitivity)

• Blood dyscrasias (pretty much all blood values are low!)

• Kernicterus (Occurs in newborns — Bilirubin induced neuro damage)

• Renal damage/toxicity

• Teratogen

What are the adverse effects associated with trimethoprim?

• Altered taste

• Epigastric discomfort

• Glossitis (tongue inflammation)

• N/V

• Pruritis

• Rash

• Teratogen

What is Bactrim?

Combination sulfamethoxazole and trimethoprim

Used to treat UTIs

When is bactrim contraindicated?

(Combined sulfamethoxazole and trimethoprim)

• Severe hepatic and/or renal impairment

• Hypersensitivity to either component

• Thrombocytopenia

• Children under age 2 (kernicterus)

What patient education should you provide to a patient who is taking bactrim?

(combined sulfamethoxazole and trimethoprim)

• Use sunscreen/protective clothing

• Notify provider for rash, fever, mouth sores, bleeding/bruising

• DON’T get pregnant — Teratogenic!

What is the first drug of choice for a lower tract UTI?

Nitrofurantoin

What is the mechanism of action for Nitrofurantoin?

• Broad spectrum

• Low concentrations = bacteriostatic (prevents growth)

• High concentrations = Bactericidal (kills em)

• Damages DNA of bacteria

• Becomes concentrated in urine

• Active against gram + and gram -

When is the administration of nitrofurantoin contraindicated?

• Oliguria (less than 400 mL urine) / anuria (none)

• Significant renal impairment

• Pregnancy near term and infants less than 1 month old

Your patient has received a new prescription for nitrofurantoin. What is important to check before administration?

• I/O for oliguria/anuria

• Renal function

• Signs of UTI (to make sure it’s indicated)

• Signs of c-diff

• LFT (hepatotoxicity)

• CBC

What are the adverse effects associated with nitrofurantoin?

• GI (anorexia, n/v/d, hepatoxicity, c-diff)

• rust/brown urine discoloration

• photosensitive

• blood dyscrasias

• hypersensitivity

• pulmonary fibrosis