Antibiotics Flashcards
Anti-infective
Target foreign organisms that cause infection; goal is reduce organisms to allow immune response to eliminate
Narrow spectrum of activity
Effective against only a few microorganisms
Broad spectrum of activity
Effective against a wide variety of microorganisms
Antibiotics
Meds used to target invading bacteria
First identify the causative organisms through a culture and then potential antibiotic susceptibilities through a sensitivity test
Empiric therapy
Treatment of an infection before specific culture information has been reported or obtains
Definitive therapy
Antibiotic therapy tailored to treat organisms identified with culture
Prophylactic therapy
Treatment with antibiotics before exposure to prevent an infection
Superinfection
Occur due to destruction of normal flora during antibiotic therapy
Commonly c.diff and yeast infections
Most common hypersensitivity reactions
Difficulty breathing, significant rash, gives, or other skin reactions, and severe GI intolerance.
Bactericidal vs bacteriostatic
Bactericidal kills bacteria
Bacteriostatic inhibits growth of susceptible bacteria rather than killing them immediately
Antibiotics MOAs
Interference with cell wall synthesis, protein synthesis, or DNA replication
Alters permeability of cell membrane
Acting as metabolite to disrupt critical metabolic reactions inside the bacterial cell
Basic sites of antibiotic activity
Cell wall synthesis, DNA replication, RNA replication, Antimetabolites, protein synthesis (30 S ribosomes or 50S ribosomes)
Class of antibiotics
Sulfonamides, penicillines, cephalosporins, macrolides, quinolones, aminoglycosides, tetracyclines
Sulfonamides
Bacteriostatic, inhibit growth of susceptible bacteria by preventing bacterial synthesis of folic acid, do not effect human cells or certain bacteria; they can use preformed folic acid
Sulfonamides indications
Effective against both gram positive and gram negative bacteria
- treatment of UTIs before sensitivity is established
- Upper respiratory tract infections
- pneumocystis jiroveci pneumonia
- outpatient staph infections
Sulfonamide contraindications
Sulfa allergy, Celebrex, pregnancy, infants less than 2 months old
Sulfonamide interactions
Sulfonylureas, warfarin, phenytoin
Sulfonamide adverse effects
Blood- hemolytic and aplastic anemia, agranulocytosis, thrombocytopenia
integumentary- photosensitivity, exfoliative dermatitis, Stevens-Johnson syndrome, epidermal necrolysis
GI- nausea, vomiting, diarrhea, pancreatitis
Other- Hepatotoxicity, convulsions, crystalluria, toxic nephrosis, headache, peripheral neuritis, urticaria, cough
Natural penicillines
Penicillin G, penicillin V
Penicillinase-resistant drugs
Nafcillin
Aminopenicillins
Amoxicillin, ampicillin
Which acid is penicillins commonly combined with
Clavulanic acid
Examples of combination agents
Amoxicillin/clavulanic acid (augmenting)
Piperacillin/ tazobactam (zosyn)
Pencillins MOA
Disrupt cell wall synthesis, bacteria cells die from cell lysis,
Prevention and treatment of infections caused by susceptible bacteria
Penicillins contraindications
Usually safe and well-tolerated meds,
KDA, assess type of reaction that occurs in patients who state they are allergic to penicillins
Penicillins adverse effects
Allergic reactions, nausea, vomiting, diarrhea, abdominal pain
Penicillins interactions
Many interactions:
Nonsteroidal anti-inflammatory drugs (reduces efficiency on antibiotics)
Oral contraceptives (lowers effectiveness)
Warfarin
Others
Cephalosporins first generation
Good gram positive coverage, poor gram negative coverage
Parental and oral forms , Used for surgical prophylaxis and for susceptible staphylococcal infections
Cephalosporins first generation drugs YNTK
Cefadroxil (duricef, ultracef)
Cephradine (velosef)
Cefazoline (ancef)
Cephalexin (keflex)
Cephalosporins second genration
Good gram positive coverage, better gram-negative coverage than first generation , surgical prophylaxis
Cephalosporins third generation
Most potent group against gram-negative bacteria
less active against gram-positive bacteria, IV and IM forms, excellent gram negative coverage, used for difficult to treat organisms, excellent spectrum coverage, resistance is limiting usefulness
Cephalosporins third generation YNTK
Cefpodoxime
Fourth generation cephalosporins
Cefepime (maxiprime)
Broader spectrum of antibacterial activity than third generation, especially against gram-positive bacteria
Uncomplicated and complicated UTI
All cephalosporins you need to know
Cefadroxil (duricef, ultracef), Cephradine (velosef), Cefazolin (ancef), cephalexin (keflex), cefpodoxime, cefepime (maxipime)
Cephalosporins adverse effects
Mild diarrhea, abdominal cramps, rash, pruritus, redness, edema, potential cross-sensitivity with penicillins if allergies exist, if you’re allergic to one you’re probably allergic to the other
Carbapenems
Bactericidal and 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
Monobactams
Synthetic beta-lactam antibiotic
primarily used for moderately severe systemic infections and UTIs - url-septic
Bactericidal
Parenteral use only
Macrolides yntk
erythromycin , azithromycin, clarithromycin
Macrolides MOA
Prevent protein synthesis within bacterial cells, considered bacteriostatic but in high enough concentrations may also be bactericidal
Macrolides indications
Strep infections, mild to moderate upper and lower respiratory tract infections, spirochete infections, gonorrhea, chlamysdia, mycoplasma
Macrolides adverse effects
GI effects primarily with erythromycin, nausea, vomiting, diarrhea, hepatotoxicity, flatulence, jaundice, anorexia
Azithromycin and clarithromycin has fewer GI adverse effects, longer duration of action, better efficacy, better tissue penetration
Tetracyclines
Natural and semisynthetic, bacteriostatic, inhibit protein synthesis
Tetracycline, doxycycline (doryx, vibramycin)
Tetracyclines MOA
Bind to Calcium, magnesium, and aluminum ions to form insoluble complexes. This blocks connection between ribosomes and RNA causing bacteriostatic effects due to inhibition of protein synthesis
Tetracycline indications
Wide spectrum- gram neg and gram pos organisms
Demeclocycline is also used to treat syndrome of inappropriate antidiuretic hormone secretion by inhibiting the action of ADH
Tetracyclines adverse effects
Strong affinity for calcium, discoloration of permanent teeth and tooth enamel in fetuses and children or nursing infants if taken by the mother- MAY RETARD FETAL SKELETAL DEVELOPMENT IN TAKEN DURING PREGNANCY
Alteration in intestinal flora
Vaginal candidiasis
GI upset
Enterocolitis
Maculopapular rash
Nursing implications for antibiotics (general)
Before beginning therapy, assess drug allergies; renal, liver, and cardiac function; and other lab studies
Be sure to obtain thorough patient health history, including immune status
Assess for conditions that may be contraindications for antibiotic use or that may be indicate cautious use
Assess for potential drug interactions
It is essential to obtain cultures from appropriate sites before beginning antibiotic therapy
Instruct patients to take antibiotics exactly as prescribes
Assess for s/s of superinfection
Monitor for therapeutic effects
All oral antibiotics are absorbed better if taken with at least 6 to 8 oz of water
Nursing implications for sulfonamides
Take with 2000 to 3000 mL of fluid/24 hours to prevent kidney issues
Assess RBC count before beginning therapy
Take oral doses with food
Avoid UV exposure and use sunglasses and sunscreen protection year long
Nursing implications for penicillins
Take oral doses with water not juices
Monitor patients taking penicillin for an allergic reaction for at least 30 minutes after administration
Nursing implications for cephalosporins
Assess for penicillin allergy, may have cross-allergy
Give orally administered forms with food to decrease GI upset even though this will delay absorption
Avoid alcohol for up to 72 hours after discontinuation. Some of these drugs may cause a disulfiram like reaction
Combined with oral anticoagulants may experience increased bleeding
Nursing implications for macrolides
Highly protein bound and will cause severe interactions with other protein-bound drugs
The absorption of oral erthyromycin is enhanced when taken on an empty stomach, but because of the high incidence of GI upset, many drugs are taken after a meal or snack
Nursing implications tetracyclines
Avoid milk products, ion preparations, antacids, and other diary products because of the chelation and drug-binding that occur
Take all medications with 6 to 8 oz of fluid preferably water
Because of photosensitivity, avoid sunlight and tanning beds
How do you prevent antibiotic resistance
Drug dosing and timing, competition of course of drug, combination therapy
What contributes to antibiotic resistance
Overuse/incomplete course, over-prescribing of broad-spectrum antibx, extensive agriculture use, availability of fresh new antibiotics/regulatory barriers
Common types of multi-drug resistant organisms
MRSA, VRE, ESBLs, CRE
Aminoglycosides
Natural and semisynthetic, poor oral absorption, very potent antibiotics with serious toxicities, bactericidal (prevents protein synthesis) , Kill mostly gram-negative bacteria, often used in combination with other antibiotics for synergistic effects
Types of ahminoglycosides yntk
Gentamicin
neomycin
tobramycin
Aminoglycosides indications
Given parenterally, can also be given via inhalation
Neomycin is given orally to decontaminate the GI tract before surgical procedures, also used as an enema for this purpose, used to treat hepatic encephalopathy, surgical prophylaxis
Aminoglycosides toxic adverse effects
Nephrotoxiticity: renal failure, toxicity in the glomerulus, bone marrow depression, immune suppression, superinfection
Ototoxicity: irreversible deafness, vestibular paralysis, confusion, depression, disorientation, and numbness, tingling, and weakness due to the drug affects on nerves
- Must monitor drug levels to prevent toxicities, if used before surgery and given with anesthetics there is and increased risk of neuromuscular blockade and paralysis
Aminoglycosides general adverse effects
Ototoxicity and nephrotoxicity
Headache, paresthesia, fever, superinfections, vertigo, skin rash, dizziness
Quinolones
Oral absorption
effective against gram negative and some gram pos
Quinolones yntk
Ciprofloxacin (cipro)
Levofloxacin (levaquin)
Quinolones MOA
Bactericidal, interferes with the action of DNA necessary for growth and reproduction of bacteria
Quinolones interactions
Oral quinolones: antacids, calcium, magnesium, iron, zinc, sucralfate
PATIENTS NEED TO TAKE INTERACTING DRUGS AT LEAST 2 HOURS BEFORE OR AFTER TAKING QUINOLONES
Diary products, enteral tube feedings, probenecid, nutrofurantioin, oral anticoagulants,
INCREASED RISK OF TENDONITIS AND TENDON RUPTURE WITH USE OF THESE DRUGS
Quinolones adverse effects
Headache, dizziness, insomnia, depressions estlnessness, convulsions, nausea, vomiting, diarrhea, constipation, thrush, increased liver function study results, PROLONGED QT INTERVAL, Rash, pruritus, urticaria, flushing, ruptured tendons, tendonitis
Clindamycin (cleocin)
Used for chronic bone infections, GU infections, intraabdominal infections, other serious infections
May cause pseudomembranous colitis
Daptomycin (Cubicin)
Only drug of the new class known as lipopetides, binds to gram pos cells in a calcium dependent process and disrupts the cell membrane potential
Used to treat complicated skin and soft tissue infections caused by susceptible gram pos bacterial including MRSA and VRE
Linezolid (Zyvox)
New class: oxazolidinones, used to treat VREF, VRE, hospital acquired structure infections
May cause hypotension, serotonin syndrome if taken with selective serotonin retake inhibitors and reactions if taken with tyramine-containing foods (citrus, aged cheeses, cured meats)
Metronidasole (flagel)
Used for anaerobic organisms, intra-abdominal and gynecological infections, protozoal infections, several drug interactions.
Nitrofurantonin (macrodantin)
Primarily used for UTIs (especially for pregnant women)
Used carefully if renal function is impaired
Drug concentrates in the urine
May cause fatal hepatotoxicity
Vancomycin
Treatment of choice for MRSA and other gram-pos infections, oral vancomycin in indicated for the treatment of antibiotic-induced colitis and for the treatment of staphylococcal enterocolitis
Must monitor blood levels to ensure therapeutic levels and prevent toxicity
- may cause ototoxicity and nephrotoxicity
Should be infused over 60 minutes
Red man syndrome may occur
Nursing considerations for fluoroquinolone
Resistent stains require culture and sensitivity tests
Associated with lesions in cartilage so not recommended for patients under 18 years of age
Advise patient to avoid sun and ultraviolet light
If taken with other drugs that cause QT prolongation severe-to-fatal cardiac reactions are possible
