Pharm Chp 7 Antimicrobial agents

Question 1

Considerations for antimicrobial agent administration

Answer 1

Location of infecting organism in the body
Status of the clients organ function
Client age
Pregnancy and/or lactation
Likelihood of developing organisms resistant to the antimicrobial agent
(TB is notorious for developing resistance easily)

Question 2

Culture and Sensitivity testing (C/S)

Answer 2

A culture is done to find out what organism is causing the infection
A sensitivity test determines what kind of antibiotic will work best to treat the infection
Obtain cultures from appropriate sites before beginning therapy

Question 3

Patient and family education about Antibiotics

Answer 3

Complete the full course of therapy Do NOT stop taking the drug even if symptoms disappear.
Take the drug at the prescribed time of day.
Take yogurt, buttermilk or Acidophilus capsules with antibiotics to reduce the risk of super infection during therapy.
Notify Dr. immediately if any one of more of the following occur: skin rash, hives, black furry tongue, vaginal or anal itching, breathing difficulty or N/V/D.
NEVER share this drug with anyone who’s symptoms are similar to yours.
Notify Dr. if symptoms of the infection do not improve or if the condition becomes worse.

Question 4

Classifications for antimicrobial agents

Answer 4

Bactericidal (Kill bacteria) or bacteriostatic (prevent growth).
Site of action
Narrow (single gram +/- effectiveness) or broad spectrum (effective on both gram +/-)
Adverse effects (Negative reaction).

Question 5

Antimicrobial classes

Answer 5

Drug Prefix
Sulfonamides (sulfa)
Penicillins (cillin)
Cephalosporins (cef or cep)
Tetracyclines (cycline)
Macrolides/Erythromycins (thromycin)
Aminoglycosides (cin)
Fluoroquinolones (oxacin)
Carbapenem (penem, comycin)
Ketolides

Question 6

Sulfonamides

Answer 6

Bacteriostatic.
Still used to treat uncomplicated UTI’s, certain vaginal infections, otitis media, and some respiratory infections.
Broad spectrum and interfere with (PABA) para-aminobenzoic acid allowing organism to synthesize its own folic acid.
Adverse effects:
Crystalluria (crystals in urine)
Must not be used near end (at term) of pregnancy. May cause jaundice in neonate.
Organisms become easily resistant.
Nursing implications:
Consume at least 3-4 liters of fluid/day.
Complete full course of therapy.
Avoid sunlight.

Question 7

Penicillins

Answer 7

Derived from fungus or mold
Called beta-lactams due to chemical structure.
Bacterial resistance is extremely high.
Most effective on newly forming cell walls.
Orally taken on empty stomach 1hr before or 2hrs after meals.
Penicillinase developed due to frequent early use, potassium clavulanate inhibits penicillinase when combined with penicillin.
Therapeutic uses:
Prevention and treatment of g+ bacterial infections.
Adverse effects:
Hypersensitivity (rash, itching, hypotension)
Superinfections.

Question 8

Super infection

Answer 8

Can develop rapidly and is potentially serious and life threatening.
Pseudomembranous colitis:
Common bacterial superinfection caused by Clostridium difficile.
Candidiasis:
Type of superinfection in the GI and reproductive systems. S/S creamy white patches on the mouth or tongue, vaginal discharge and anal or vaginal itiching.
If penicillin destroys Doderlein’s bacteria in the vagina, yeast becomes uncontrolled, multiplies rapidly and can cause candidiasis or moniliasis.

Question 9

Cehpalosporins

Answer 9

Chemically and pharmacologically related to penicillins.
Action depends on:
Bacteriostatic
Susceptibility of organism
Dose of drug
Tissue of concentration
Rate of bacteria multiplication
Classes:
1st gen- good g+ coverage.
2nd gen- good g+ coverage, some g- coverage.
3rd gen- less g+ coverage, more g- coverage.
4th gen- good g- coverage.
Cross-sensitivity reaction to penicillin.

Question 10

Tetracyclines

Answer 10

Action: Bacteriostatic and broad spectrum effective on protozoa as well as bacteria.
Never give with dairy products, antacids or iron salts as these will prevent absorption in the intestines.
Do NOT give to children under 8 years of age as it will interfere with bone and teeth development and cause teeth staining.
Avoid sunlight from 10-4 due to photosensitivity.
Risk of superinfection.

Question 11

Macrolides

Answer 11

Bacteriostatic (prevents organism growth) and Bacteriocidal (kills bacteria)
Erythromycin (pertussis) and azithromycin are examples of drug.
Adverse effects:
Hepatotoxicity (liver toxic) tests nurses must monitor for liver damage while pt is on drug are;
Alanine amino transferase (ALT) normal 10-40 U/L
Aspartate aminotransferase (AST) normal 0-41 U/L
Bilirubin, total normal 0.2-1.0 mg/dL

Question 12

Aminoglycosides

Answer 12

Given IV or IM
Bactericidal
Narrow therapeutic range MEC and MTC very small.
Potent antibiotic with serious toxicities.
Nephrotoxicity (Kidney damage)
Ototoxicity (Ear damage)
Can lead to respiratory paralysis.
Must monitor both peak and trough drug levels.

Question 13

Fluoroquinolones

Answer 13

Bactericidal: alter organism DNA
Broad spectrum especially effective agains Pseudomonas aeruginosa (green mucous, discharge)
Excellent oral absorption.
Pt must drink at least 1 L/day of fluids to decrease crystalluria.

Question 14

Carbapenems

Answer 14

Bacteristatic (prevent growth, and cause death of susceptible cells.
Broad spectrum
Treat community acquired pneumonia and pseudomonas aeruginosa.
Cross-sensitivity to penicillin.
Given once every 24 hours.

Question 15

Ketolides

Answer 15

FDA approved in 2004.
New class developed from macrolides.
Semisynthetic derivatives of erythromycin.
Treat macrolide-resistant strep pneumonia.

Question 16

Vancomycin

Answer 16

Bactericidal antibiotic used to treat serious infections that cannot be treated with less toxic agents, such as penicillins or cehpalosporins.
Useful in treating pseudomembranous colitis produced by C. diff.
May cause ototoxicity and nephrotoxicity.
Tests to check kidney function; uria uric acid and creatinine (most reliable test).
By IV route hypotension, pain and thrombophlebitis occur.

Question 17

Urinary tract anti-infectives

Answer 17

Trimethoprim/sulfamethoxazole (Septra)
Most commonly used urinary anti-infective.
Methenamine: local bactericidal effect.
Nitrofurantoin: stops CHO metabolism
Phenazopyridine (Pyridium): Topical analgesic effect on mucosal lining of urinary tract.

Question 18

Antitubercular agents

Answer 18

TB requires oxygen to survive.
Drug therapy given in 2 forms:
Preventative and Active
INH (Isoniazid) known as chemoprophylaxis
adverse effect Hepatotoxicity (jaundice)
Multi drug therapy of 2 or more agents required to prevent resistant strain development.

Question 19

Antitubercular agent therapy

Answer 19

Pt education is critical
Therapy can last up to 24 months
Med must be taken as ordered
Emphasize importance of strict compliance
To prevent non-compliance (DOT) directly-observed therapy is used to administer drugs.

Question 20

Antitubercular agent therapy cont’d

Answer 20

Supplement INH therapy with vitamin B6 to prevent neuropathy.
Family members of infected must be given prophylactic treatment with INH for 6 months to 1 year.

Question 21

Rifampin therapy

Answer 21

Bodily fluids may be colored orange-red, this is normal.
Diabetics, monitor blood glucose levels.
Oral contraceptives are ineffective.
Monitor pt monthly for S/S of hepatic dysfunction; anorexia, fatigue, weakness, jaundice, dark urine, check lab test (AST, ALT, bilirubin).
Instruct pt to report any of these sypmtoms.

Question 22

Lyme disease

Answer 22

Borrelia burgdorferi- transmitted from deer tick.
S/S Bulls eye rash, flulike. Best treated in early stages.
Treatment- Oral doxycycline.

Question 23

Fungi

Answer 23

Contracted thru air and skin to skin.
Mycotic infections 3 general types;
Cutaneous (least life threatening)
Subcutaneous
Systemic (can be life threatening)

Question 24

Antifungal agents

Answer 24

Antibiotic therapy will not work.
Requires prolonged treatment due to cell structure resembling human cell structure.
Agents take advantage of the slight differences of the cell sturctures.

Question 25

Antiviral agents

Answer 25

Viruses cause many infectious disorders:
Acute: common cold
Chronic: herpes
Slow: AIDS
A virus cannot replicate on its own, it must attach to and enter a host cell in order to synthesize protein (reproduce itself).
Agents end in “vir”
Limited in ability to treat infections due to damage to host cell.
Agents are used to treat influenza A and B, Herpes, RSV, HIV, and Hepatitis B and C.
Teach proper application of ointments and aerosol powders. To wear gloves for topical solutions.