566 Midterm Study Guide WEEK 1 -Things to know about each of the major antibiotic drug classes
· Contraindications and high-risk patients
· Know examples of each of the major antibiotic drug classes
· Monitoring needs
· Which ones require renal dosing adjustments and how much (i.e., 25%, 50%, etc.)
· Patient education
· Lifespan considerations including pregnancy
· Indications for use
Penicillins
caution with patients allergic reactions to penicillins, cephalosporins, or carbapenems
Treats infection cause by sensitive bacteria
check culture to identify infecting organism
Can order skin test to assess allergy status
adjusted doses for patients with impaired renal fnx
NARROW SPECTRUM PENICILLINS: PENICILLIN SENSITIVE(PEN G &PEN V)
-Mechanism of Action : “Bactericidal”- Weakens the cell wall, causing bacteria to take up excessive amounts of water and rupture. Occurs by two actions simultaneously: inhibiting transpeptidases and activating autolysins
which disrupts synthesis of the cell wall and promotes the active destruction resulting in cell lysis and death.
-Examples: Penicillin G (Prototype Drug), Penicillin V , Nafcillin, Oxacillin, Dicloxacillin, Ampicillin, Amoxicillin, Piperacillin
Penicillin G-
-First Penicillin Available and often referred to plainly as Penicillin
-Bactericidal for gram negative and gram positive bacteria
-Should be taken with medications whereas Penicillin V is stable in stomach acids.
-Side Effects: Allergic reactions, pain at IM injection sites, prolonged (but reversible) sensory and motor dysfunction if injected into peripheral nerves, and neurotoxicity (seizures, confusion, hallucinations- if levels too high)
.
-Life Span Considerations:
*Infants- Used safely in infants with bacterial infections including syphilis, meningitis, & group A streptococcus
*Children/Adolescents- Common drug used to treat bacterial infections in children.
*Pregnant- No well controlled studies but evidence suggests no 2nd or 3rd trimester fetal risk.
*Breastfeeding- Amoxicillin is safe. Data is lacking about transmission of other PCNs from
mother to infant through breast milk.
*Older Adults- Doses should be adjusted in older adults with renal dysfunction. Penicillin Allergy:
-Most common drug allergy to date with severity ranging from minor rash to anaphylaxis
-Can possibly display cross sensitivity to cephalosporins and should not be used if possible
-observed 30 minutes minimum post drug injection for adverse reactions
-For history of PCN allergy , a skin allergy test can be done to assess current risk by injecting a tiny amount of allergen ID (only to be done where epinephrine and respiratory support is available if needed)
Penicillin V-
Stable in stomach acid ( Pen G is not)
Used for oral therapy, can be taken with meals
NARROW SPECTRUM PENICILLIN: PENICILLIN RESISTANT: (Nafcillin, Oxacillin, Dicloxacillin)
-Treats S. aureus and S. epidermidis
Broad-Spectrum Penicillins ( Ampicillin & Amoxicillin ): -Most common side effects are rash and diarrhea (rash usually 3-10 days post TX start).
-Therapy can be PO or IV and requires dosage adjustment for renal impairment
-Treats Haemophilus influenzae, E. Coli, proteus mirabilis, enterococci, and Neisseria gonorrhoeae
EXTENDED SPECTRUM PENICILLIN: (Piperacillin) -Treats same diseases as broad spectrum PLUS: *pseudomonas aeruginosa*, enterobacter spp, proteus, bacteroides fragilis, klebsiella spp
-Can cause bleeding secondary to disrupting platelet function
-Usually administered IV
-Reduce dose in renal pt’s
Cephalosporins (Cephalexin) -Bactericidal drug (similar to PCNs)
-Increases activity against gram-negative agents
-Increases ability to reach cerebral spinal fluid (CSF)-3rd,4th,5th generations
-no routine lab monitoring
-Administered IM or IV
-Take cultures to determine sensitivity and infecting organism
-Contraindicated in pt’s with severe allergic reaction to cephalosporins or penicillins
- CAN CAUSE C. DIFF INFECTION (tell pt. To monitor for frequent stools)
-Used to treat infants & neonates. Especially in otitis media and gonococcal and pneumococcal infections
-Adverse Effects: Maculopapular rash, bronchospasm, anaphylaxis
-Education: Patients should not consume alcohol
First generation: tx’ s staphylococci or streptococci Cefadroxil, Cefazolin, Cephalexin
Second generation: TX’ s H. Influenza, Klebsiella, pneumococci, staphylococci Cefaclor, Cefotetan, Cefoxitin, Cefurozime
Third generation: tx’ s pseudomonas aeruginosa, Neisseria gonorrhoeae, Klebsiella, Serratia Cefdinir, Cefotaxime, Cefpodoxime, Ceftazidime, Ceftriaxone
Fourth generation: Pseudomonas aeruginosa Cefepine, Ceftolozane/tazobactam
Fifth generation: Methicillin resistant Staphylococcus aureus
Ceftaroline Carbapenems (Imipenem)
-Patients on valproate for seizures not to give
-Avoid in renal impairment pts
-Adverse effects: N/V/D, seizures (rare), rashes, pruritus
Vancomycin
-Used for C. Diff infection
-Treats S. Aureus and S. epidermidis, and MRSA
-Monitor Vanco drug levels
-Use caution in pt’s with renal impairment
Telavancin
-Black Box Warning : when used to tx hospital acquire or ventilator-associated bacterial pneumonia with creatinine clearance of less thn 50 ml/min, increased chance of mortality. Not safe in pregnancy Aztreonam
-Adverse effects: pain & thrombophlebitis at injection site
USES: -treats gram negative bacteria: E. Coli, salmonella, Shigella, Serratia, Klebsiellam Proteus, H. influenza, P. aeruginosa
Fosfomycin
-Single dose therapy in women with uncomplicated UTI
-Adverse effects: diarrhea, headache, vaginitis, nausea, abdominal pain, rhinitis, drowsiness, dizziness, rash
Tetracyclines (Tetracycline)
-Broad spectrum bacteriostatic
-Contraindication/Precautions:
- After the 4th month of pregnancy can stain deciduous teeth and stain permanent teeth of children ages of 4 month and 8 years
- If given to treat an STD, abstain from intercourse until med is finished.
o Food decreases absorption
· Complications
o GI discomfort (cramping, nausea, diarrhea, and esophageal ulceration )
§ Taking Doxycycline and Minocycline with meals will with GI discomfort BUT food will reduce absorption.
§ Avoid taking at bedtime to reduce the risk of esophageal ulceration. o Yellow/Brown tooth discoloration, Hypoplasia of tooth enamel, Effects on bones
§ Avoid in children younger than 8 and women who are pregnant.
§ Can suppress the growth of long bones in premature infants .
o Hepatoxicity (lethargy, jaundice)
§ Avoid high daily doses IV.
§ Fatty infiltration of the liver
o Photosensitivity (exaggerated sunburn )
§ Use sunscreen with an SPF 30 or higher.
o Superinfection of the Bowel
§ C-diff associated diarrhea AKA antibiotic-associated pseudomembranous colitis. D/C med immediately
§ Yeast infections of the mouth, pharynx, vagina
o Dizziness. Lightheadedness (Minocycline)
o Renal Toxicity
· Contraindication/Precautions
o After the 4th month of pregnancy can stain deciduous teeth and stain permanent teeth of children ages of 4 month and 8 years
o If given to treat an STD, abstain from intercourse until med is finished.
· Interactions
o Interaction with milk products, calcium, iron supplements, laxatives containing magnesium and antacids causes formation of nonabsorbable chelates, thus reducing the
absorption of tetracyclines.
§ Administer 1 hour BEFORE or 2 hours ingestion of chelating agents.
o Increase the risk of digoxin toxicity and increase INR by altering Vitamin K -producing flora in the gut.
o Decrease efficacy of oral contraceptives – use alternative form of birth control.
Life Stage Patient Care Concerns
Children/adolescents Tetracyclines should not be used in children younger than 8 years because they may cause permanent discoloration of the teeth.
Pregnant women Animal studies reveal that tetracyclines can cause fetal harm in pregnancy. Thus, this class of drugs should be avoided in pregnant women.
Breastfeeding womenUse of tetracyclines during tooth development can cause permanent staining. Tetracyclines should be avoided by breastfeeding women.
Older adults Tetracyclines can interact with drugs, including digoxin. In the older adult who takes many medications, check for interactions.
Macrolides (Erythromycin)
· Uses
o Treatment of choice for Corynebacterium diphtheria and may be used as an alternative to Penicillin G in patients with PCN allergy.
o Treats chlamydial infections, pneumonia d/t Mycoplasma pneumonia , & streptococcal
infections
