AntibioticsQuang TruongJennafer McCoy

Categories of IV antibiotic medications Sulfonamides - Treatment: UTIs and GI Infections

Penicillins - Bactericidal agents, many therapeutic uses; prevents bacteria from forming rigid walls

Cephalosporins - Same mechanism as penicillin, cover a broader spectrum of organisms

Tetracyclines - Bacteriostatic

Quinolones- Penetrate bone and joints

Aminoglycosides - Commonly used against serious life-threatening (septic) infections; Bactericidal

Uses for the drugs1)Inhibit cell wall formation

2)Block protein formation

3)Disrupt cell membrane

4)Interfere with DNA formation

5)Prevent folic acid synthesis

Dosages & How they are calculated

Sulfonamide-Bactrim IV dose: 8-10mg/kg/day divided q6-12h Calculated: By appropriate culture/susceptibility studies

Penicillin-Penicillin G IV dose: 2-24 million units/day in divided doses q4h Calculated: Depending on organism sensitivity and severity of infection

Cephalosporin-Cefoxitin IV dose: 1g- 2g q6-8h Calculated: By causative organism susceptibility, severity of infection, and patient’s condition

Tetracyclines-Minocycline IV dose: 100mg q12h not to exceed 400mg/24hs Calculated: With culture and susceptibility information

Quinolones-Ciprofloxacin IV dose: 500mg q12h for 4 to 6 wks. Calculated: By severity/nature of the infection, integrity of patient’s host-defense mechanisms, and status of renal/hepatic function

Aminoglycosides-Amikacin IV dose: 5 to 7.5 mg/kg/dose q8h Calculated: Based on IBW or adjusted body weight if current weight is > than 25-30% over IBW

ActionBactericidal Vs. Bacteriostatic

Bacteriostatic is capable of inhibiting the growth or reproduction of bacteria

Bactericidal is capable of killing bacteria outright

Onset and duration of actionOnset-immediately since the medications

are given intravenously

Duration- Varies according to duration of treatment; the effects of continue to work after treatment is completed

ContraindicationsPatients should avoid sun, dairy,

antacids, anticoagulants, anti-seizures, consuming alcohol or medications containing alcohol, pregnancy, and breastfeeding, etc. (varies depending specific type of antibiotic)

Possible drug interactionsRuins the effects of the antibiotic or could

cause a severe reaction.

Anti-seizure

Anticoagulants

Bethkis (tobramycin)

Cisatracurium

Doxacurium

Potential dangers associated with useSulfonamides – rash, N/V, HA

Penicillins – diarrhea, N/V

Cephalosporins – similar to penicillin

Tetracyclines - GI discomfort, N/V; Can cause fatal renal syndrome

Quinolones - GI discomfort, N/V, dizziness

Aminoglycosides - mild hearing loss, mild dizziness, clumsiness, N/V, etc.

Length of time on marketSulfonamides – Discovered in 1932, marketed in 1935

Penicillins – Discovered in 1928, marketed on March 15, 1945

Cephalosporins – Discovered in 1950, marketed in 1964

Tetracyclines – Discovered in 1948, marketed in 1955

Quinolones – Discovered in 1962, marketed for clinical use in 1967

Aminoglycosides – Discovered in 1943, marketed in 1963

CostIV medications are more costly

Switching from (IV) to oral (PO) therapy as soon as patients are clinically stable can reduce the length of hospitalization and lower associated costs

While intravenous medications may be more bioavailable and have greater effects, some oral drugs produce serum levels that are the same or comparable to those of the IV form

Resources www.drugs.com

www.ncbi.nlm.nih.gov

www.faqs.org/health

www.globalrph.com/antibiotics

www.oxfordjournals.org

www.fda.gov

www.psr.org

www.aafp.org