Extended Spectrum Penicillins
·
Also known as Antipseudomonal Penicillins
·
Broad-Spectrum
·
Well absorbed in the GI tract
·
Affective against Pseudomonas Aeruginosa (a gram
negative bacillus that if difficult to eradicate)
·
Can also be used to eradicate other
gram-negative organisms such as Proteus spp., Serratia Spp. Klebsibelle
Pneumoniae, Enterobacter spp. And Acinetobacter spp.
·
Can be given IM, IV, or oral
·
Medications:
o
Carbenicillin Indanyl (Geocilin): Given in po
form in a range of 382-764mg Q6H to adults only. This medication is used to
treat infections caused by Proteus spp. And Pseudomonas Aeruginosa. Should be used with caution in clients with hypertension or
heart failure because this medication contains large amounts of sodium
o
Piperacillin-tazobactam (Zosyn): Given in IV
form 3.375g, Q6H over 30 minutes for a duration of 7-10 days to adults
only. Has many uses such as severe
appendicitis, skin infections, pneumonia, and beta-lactamase-producing bacteria
(tazobactam is a beta-lactamase inhibitor) Monitor
hepatic and renal function, electrolytes as well. One of the most common
electrolyte imbalances to occur is hypokalemia. Can cause complications in
cystic fibrosis patients.
o
Ticarcillin-clavulanate (timentin): can be given
IV to adults 3.1 grams Q6H, or children older than 3 months based on weight
200-300 mg/kg/day in 4-6 divided doses. Indicated in the treatment of
septicemia, and lower respiratory tract infections, urinary tract infections,
skin infections, bone infections, and joint infections. Clavukanic acid
protects ticarcillin from degradation by beta-lactamase enzymes. Monitor hepatic and renal function, electrolytes as well. One
of the most common electrolyte imbalances to occur is hypokalemia. Make sure
that patient is aware that diarrhea can occur as late as 2+ months after last
dose of medication and make sure that patient knows to report diarrhea to MD.
Beta-Lactamase Inhibitors
·
Combined with broad spectrum antibiotics
·
When combined the beta-lactamase inhibitor
inhibits the bacterial beta-lactamases making the antibiotic more effective and
extends the antibiotics antimicrobial effect
·
Three beta-lactamase inhibitor: clavulanic acid,
sulbactam, and tazobactam.
·
The above beta-lactamase inhibitors are not given
alone, they are combined with a penicillinase-sensitive penicillin (examples
incude amoxicillin, ampicillin, piperacillin, or tiracillin)
·
Combined drugs currently on the market
o
Piperacillin-tazobactam (Zosyn): Given in IV
form 3.375g, Q6H over 30 minutes for a duration of 7-10 days to adults
only. Has many uses such as severe
appendicitis, skin infections, pneumonia, and beta-lactamase-producing bacteria
(tazobactam is a beta-lactamase inhibitor) Monitor
hepatic and renal function, electrolytes as well. One of the most common
electrolyte imbalances to occur is hypokalemia. Can cause complications in
cystic fibrosis patients
o
Ampicillin-Sulbactam (unasyn): given IV- dosing
in adults 1.5-3g Q6H, dosing in children 100-300mg/kg/day divided Q6H. Effective against gram negative and gram
positive bacteria, people who have allergies penicillin may be allergic to
ampicillin. Monitor for GI changes, hematological
changes –most common agranulocytosis, monitor hepatic and renal function,
monitor estrogen levels in pregnant women because this medication can cause a
false positive for glucose with the clinitest, bemedicts solution, or fehlings
solution.
o
Amoxicillin-Clavulanic acid (augmentin): given
in PO doses- Adult dosing 250-500 mg Q8-12h, Childrens dosing – if the child
weighs less than 40 kg than dosing is 20-40 mg/kg/day. This medication is used
to treat lower respiratory infections, otitis media, sinusitis, skin infections
and UTI’s. Monitor renal function, hepatic function and
electrolytes. Monitor for cholestatic jaundice. Make sure that patient is aware
that diarrhea can occur as late as 2+ months after last dose of medication and
make sure that patient knows to report diarrhea to MD.
o
Ticarcillin-clavulante (Timentin): given IV. In
adults 3.1g Q6H and in children who are
>3 months in age dosing in 200-300mg/kg/day in 4-6 divided doses. Indicated
in the treatment of septicemia, and lower respiratory tract infections, urinary
tract infections, skin infections, bone infections, and joint infections. Clavukanic
acid protects ticarcillin from degradation by beta-lactamase enzymes . Monitor hepatic and renal function, electrolytes as well. One
of the most common electrolyte imbalances to occur is hypokalemia. Make sure
that patient is aware that diarrhea can occur as late as 2+ months after last
dose of medication and make sure that patient knows to report diarrhea to MD.
Considerations:
·
Common side effects: hypersensitivity and
superinfection (occurance of a secondary infection when the flora of the body
is disturbed. GI disturbances (nausea,
vomiting, and diarrhea) Rash = mild to moderate allergic reaction, Signs of a
severe anaphylactic reaction include laryngeal edema, severe
bronchoconstriction with stridor and hypotension.
***
Always finish full dose of all antibiotics
By: Corey Bradley
Mechanism
of action:
Penicillin works by interfering with bacterial cell wall
synthesis. Penicillin has a beta-lactam
ring structure, which interferes with from four to eight (depending on the
bacteria) related enzymes responsible for bacterial cell division and bacterial
wall synthesis. (Calderwood, S. B.,
2014) Penicillin can be bactericidal and
bacteriostatic. Bacteria can combat
penicillin and other antibiotics by producing beta-lactamases. In the case of penicillin, these
beta-lactamases are called penicillinases.
(Kee, Hayes & McCuistion, 2012)
Broad
Spectrum Penicillins:
Indications/Dosage:
Amoxicillin (Amoxil): Treatment
of gram positive and gram negative bacterial infections such as skin
infections, lower respiratory tract infection, otitis media, skin infection,
and gonorrhea. Adult: PO250-500 mg q8-12 hours; Child: PO 20-40 mg/kg/d in 3 divided doses.
Amoxicillin-clavulanate (Augmentin):
Treatment of sinusitis, lower respiratory tract infections, pneumonia,
skin infection. Adult: PO:250-500 mg q8-12 hours; Child: PO: <40
kg: 20-40 mg/kg/d
Ampicillin (Principen)- treatment of gram positive/gram negative cocci;
gram positive bacilli; respiratory, GI and GU infections; meningitis;
septicemia; endocarditis. Adult:
PO/IM/IV: 250-500 mg q6h; Child: PO/IM/IV: 25-50 mg/kg/d in 4 doses
Ampicillin-sulbactam (Unasyn)- skin infections; intra-abdominal
infections; pneumonia; gynecologic infections; meningitis; septicemia. Adult: IV: 1.5 to 3 g q6 hours; Child: IV:
100-300 mg/kg/d in 4 doses.
(Skidmore-Roth, 2012)
Penicillinase-Resistant
Penicillins:
Indications/Dosages:
Dicloxacillin sodium (Dynapen): treatment of staphylococcus aureus
infection. Adult: PO: 1250500 mg q6
hours; Child: PO: 12.5-25 mg/kg/d in 3 divided doses.
Nafcillin (Nallpen): treatment
of penicillin G-resistant Staphylococcus aureus. Adult: IM/IV: 500 mg- 1g q4-6 hours, max 12
g/day. Child: IM: 25 mg/kg b.i.d. IV: 50-200 mg/kg/d in 4-6 doses, max 12
g/day
Oxacillin sodium (Bactocill):
For penicillin-resistant staphylococci.
Adult: PO: 500mg -1 g, q 4-6 hours.
IM/IV: 250mg to 1 g, q4-6 hours. Child:
PO/IM/IV: 50-100 mg/kg/d in divided doses
Pharmacokinetics:
Amoxicillin-
greater than 80% absorbed in the GI tract, it is 20% protein bound, with 60-70%
excreted in the urine. Its half-life is
1-1.5 hours. Clavulanate is 30-40%
excreted in urine. Fifty percent of
Ampicillin is absorbed in the GI tract, it is 15-28% protein bound, with a
half-life of 1-2 hours. Sulbactam has
the same absorption, is 28-38% protein bound, with a half-life of 1-2 hours. Dynapen is absorbed 35-76% in the GI tract,
it is 95% protein bound, it’s half-life is 0.5-1 hour. It is 90% protein bound, and its half-life is
1 hour. Bactocill is 95% protein bound,
with a half-life of 0.5-1 hour.
Pharmacodynamics:
Amoxicillin interferes with cell-wall synthesis, causing cell
destruction. Clavulanic acid added in
Augmentin increases the effect of amoxicillin by decreasing resistance to the
drug. Onset is 0.5 hour, peak 1 hour,
duration 4-6 hours.
(Kee, Hayes & McCuistion, 2012)
Side
Effects: Amoxicillin; Ampicillin;
Augmenten: Nausea,
vomiting, diarrhea, rash, edema, stomatitis; Dicloaxdillin: abdominal pain, flatulence; Nafcillin; Oxacillin: Nausea, vomiting, diarrhea, rash.
Adverse
reactions: Superinfections; Severe: respiratory distress, anaphylaxis,
hypotension, blood dyscrasias, hemolytic anemia, bone marrow depression.
By: Christine Barlow
One note to make sure to differentiate is that fact that Zosyn and Timentin are antipseudomonal but Unasyn and Augmentin are NOT. They all cover basic enterbactereciae but not the ugly ones like pseudomonas, serratia. Counsel patient on the need to use a backup method of birth control if they are on oral contraceptives and penicillins. Penicillins have the highest rate of drug reaction so monitor for signs/symptoms.
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