Penicillin dosing

Binding of (3-lactam antibiotics to PBP-1A and PBP-1 B (transpeptidase) of Escherichia coii leads to cell lysis to PBP-2 (transpeptidase) leads to oval cells deficient in rigidity and to inhibition of cell division to PBP-3 (transpeptidase) leads to abnormally long, filamentous shapes by failure to produce a septum and to PBP-4 through PBP-6 (carboxypeptidases) leads to no lethal effects. Approximately 8% of a dose of benzylpenicillin binds to PCP-1, 0.7% to PCP-2, 2% to PBP-3, 4% to PBP-4, 65% to PBP-5, and 21% to PBP-6. Thus, the majority of the penicillin dose bonds to PBPs for which the function remains obscure. Binding to PBP-1 is lethal. Other (3-lactam antibiotics display different binding patterns. Amoxicillin and the cephalosporins bind more avidly to PBP-1, methicillin and cefotaxime to PBP-2, and mezlocillin and cefuroxime to PBP-3. All these drugs are lethal to susceptible bacteria. 

Me otrexate Penicillin (dose) Indication (number of patients) Outcome Refs... 

The nurse should take and record vital signs. When appropriate, it is important to obtain a description of the signs and symptoms of the infection from the patient or family. The nurse assesses the infected area (when possible) and records finding on the patient s chart. It is important to describe accurately any signs and symptoms related to the patient s infection, such as color and lype of drainage from a wound, pain, redness and inflammation, color of sputum, or presence of an odor. In addition, the nurse should note the patient s general appearance. A culture and sensitivity test is almost always ordered, and the nurse must obtain the results before giving the first dose of penicillin. 

Adequate blood levels of the drug must be maintained for die agent to be effective. Accidental omission or delay of a dose results in decreased blood levels, which will reduce the effectiveness of the antibiotic. It is best to give oral penicillins on an empty stomach, 1 hour before or 2 hours after a meal. Bacampicillin (Spectrobid), penicillin V (Pen-Vee K), and amoxicillin (Amoxil) may be given without regard to meals. 

Isolated seizures that are not epilepsy can be caused by stroke, central nervous system trauma, central nervous system infections, metabolic disturbances (e.g., hyponatremia and hypoglycemia), and hypoxia. If these underlying causes of seizures are not corrected, they may lead to the development of recurrent seizures I or epilepsy. Medications can also cause seizures. Some drugs that are commonly associated with seizures include tramadol, bupropion, theophylline, some antidepressants, some antipsy-chotics, amphetamines, cocaine, imipenem, lithium, excessive doses of penicillins or cephalosporins, and sympathomimetics or stimulants. 

The antibiotic of choice for group B streptococcal disease is penicillin G, although ampicillin is an alternative.43 No resistance to either agent has been reported, and their narrow spectrum of activity makes them ideal choices.43 Resistance has developed with the use of alternative choices for penicillin-allergic patients. A treatment algorithm for group B Streptococcus is shown in Fig. 44—3, and dosing recommendations are shown in Table 44-5. 

Children with SCD should receive prophylactic penicillin until at least the age of 5 years, even if they have been immunized appropriately with PCV 7 against pneumococcal infections. Penicillin V potassium typically is initiated at age 2 months with a dose of 125 mg orally twice daily until age 3 years and then 250 mg orally twice daily until 5 years of age. The intramuscular use of benzathine penicillin 600,000 units every 4 weeks from age 6 months to 6 years is also an option for non-compliant patients. Penicillin-allergic patients may receive erythromycin 10 mg/kg twice daily. Penicillin prophylaxis usually is not continued in children over the age of 6 years but may be considered in patients with a history of invasive pneumococcal infection or surgical splenectomy.6,18-20... 

Penicillin G 0.15 million units/kg IV per day in divided doses every 8-12 hours 0.2 million units/kg IV per day in divided doses every 6-8 hours 0.3 million units/kg IV per day in divided doses every 4-6 hours... 

Traditionally, high-dose penicillin G was the treatment standard for meningococcal disease. However, increasing penicillin resistance requires that third-generation cephalosporins now be used for empirical treatment until in vitro susceptibilities are known.23 Patients with a history of type I penicillin allergy or cephalosporin allergy may be treated with vancomycin. Treatment should be continued for 7 days, after which no further treatment is necessary. 

FIGURE 69-3. Treatment algorithm3 for acute bacterial rhinosinusitis in patients with mild disease without recent antibiotic exposure.31 aAntibiotics are listed in order of predicted efficacy based on predicted clinical and bacteriologic efficacy rates, clinical studies, safety, and tolerability. Doses can be found in Table 69-4. 6Cephalosporins should be considered for patients with non-type I hypersensitivity to penicillins they are more likely to be effective than the alternative agents. cHigh doses (90 mg/kg per day) are recommended for most children, especially those with day-care contacts or frequent infections. 

Penicillin G benzathine 1.2 million units 600,000 units (if under 27 kg) 1 IM dose Useful for nonadherence or emesis painful injection... 

Amoxicillin 250-500 mg 3 times daily 750 mg daily being studied 40-50 mg/kg per day in 3 doses 10 days Preferred over penicillin V for young children (more palatable)... 

Cephalexin 250-500 mg 4 times daily 25-50 mg/kg per day in 4 doses 10 days Consider in penicillin allergy (if non-type I reaction)... 

If GAS is identified as the sole causative organism from deep tissue culture, antimicrobial therapy can be narrowed to high-dose IV penicillin G plus clindamycin. Antibiotic therapy should be continued until further operative debridements are unnecessary, the patient displays substantial clinical improvement, and fevers have abated for at least 48 to 72 hours.3... 

Pediatric dose penicillin less than 1 mcg/mL when 3 divided... 

For enterococci, it is imperative to determine species and antibiotic susceptibilities. If the organism is susceptible to penicillin and vancomycin, treatment may consist of high-dose penicillin G, ampicillin, or vancomycin plus gentamicin (see Table 71-6). Treatment length is usually 4 to 6 weeks, with the aminoglycoside used over the entire course. As resistance develops to penicillin, ampicillin and vancomycin remain treatment options. Once the isolate becomes resistant to ampicillin, vancomycin is considered the treatment of choice. 

For penicillin-allergic (nonanaphylactoid type) patients cefazolin 6 g/24 hours IV in 3 equally divided doses 6 IB Consider skin testing for oxacillin-susceptible staphylococci and questionable history of immediate-type hypersensitivity to penicillin cephalosporins should be avoided in patients with anaphylactoid-type hypersensitivity to P-lactams vancomycin should be used in these cases ... 

Penicillin C 24 million units/24 hours IV in 4 to 6 equally divided doses may be used in place of nafcillin or oxacillin if strain is penicillin-susceptible (minimum inhibitory concentration less than or equal to 0.1 mcg/mL) and does not produce P-lactamase. cGentamicin should be administered in close temporal proximity to vancomycin, nafcillin, or oxacillin dosing. 

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