| Parenteral Antimicrobial Agent | Common Adult Parenteral Doses | Monitoring/Unusual Adverse Effects | PK/PD | Elimination | T 1/2 | Action | Cidal/Static (may not be clinically relevant) |
| Anti-staphylococcal Agents (*MRSA) | |||||||
| Nafcillin | 1 to 2 g every 4 to 6h | Nafcillin is an inducer of the cytochrome P450 3A4, Periodic CBC, urinalysis, BUN, SCr, AST and ALT, can cause mild hypokalemia | T>MIC | Billary | 0.5-1 hr | Exerts bactericidal activity via inhibition of bacterial cell wall synthesis by binding one or more of the penicillin binding proteins (PBPs). | bactericidal |
| Cefazolin | 1 gm q 6h | BUN, SCr, AST and ALT, skin rash, neutropenia and leukopenia | T>MIC | Renal (adjust doses) | 2 | Exerts bactericidal activity via inhibition of bacterial cell wall synthesis by binding one or more of the penicillin binding proteins (PBPs). | bactericidal |
| Vancomycin* | 15-20 mg/kg | Serum concentrations, BUN, SCr, skin rash, Neutropenia | 24-hr AUC/MIC | Renal | 6 | Vancomycin inhibits transpeptidation by binding to D-alanyl-D-alanine residues of the bacterial cell wall. | |
| Linezolid* | 600 mg q12h | myelosuppression (reversible) – thrombocytopenia (most common), anemia, leukopenia Lactic acidosis Peripheral neuropathy, optic neuropathy Serotonin syndrome from interaction with SSRI antidepressants, weekly complete blood counts with differential are recommended to monitor for myelosuppression related adverse events, particularly in those that receive the drug for greater than 2 weeks | 24-hr AUC/MIC | Renal | 5 | Inhibition of bacterial ribosomal protein synthesis by binding to the 23S portion of the 50S ribosomal subunit. | bacteriostatic |
| Trimethoprim/Sulfamethoxazole* | 160/800 mg q 12h | Monitor renal function tests, serum potassium (Hyperkalemia especially in renal insufficiency or when using ACE/ARB). | time dependnat | Renal | 1-4 h | Sulfamethoxazole inhibits the synthesis of dihydrofolic acid. Trimethoprim inhibits thymidine and DNA synthesis. These two agents act synergistically in inhibiting folic acid synthesis. | bacteriostatic |
| Daptomycin* | 4-6 mg/kg q24h (do not use in pneumonia) | rhabdomyolysis, CPK levels should be monitored weekly. Daptomycin should be discontinued in patients with unexplained signs and symptoms of myopathy in conjuction with CPK elevation > 1000U/L, or in patients without reported symptoms who have marked elevations in CPK (>2000U/L). | 24-hr AUC/MIC | Renal | 8-9 | Calcium-dependent binding/insertion of the lipophillic tail into gram-positive cyotplasmic membrane. Oligomerization/channel formation occurs with subsequent ion leakage and collapse of organism leading to cell death. | |
| Doxycycline* | 100 mg q 12h | Photosensitivity and hyperpigmentation, tinnitus, teeth and bone discoloration, visual distrubances, Hypersensitivity syndrome reaction, serum sickness like reaction or single organ dysfunction – Monitor: CBC, LFTs, urinalysis, urea, creatinine, chest radiograph, Drug-induced lupus: monitor antinuclear antibody and hepatic transaminases General long-term therapy: Liver and renal function tests, Hematopoietic studies. Do not give with medications containing magnesium, aluminum, or calcium | 24-hr AUC/MIC | biliary, renal | 18 | Inhibits bacterial protein synthesis by binding with the 30S ribosomal subunit. | bacteriostatic |
| Clindamycin* | 600 to 900 mg every 8 to 12h | C. difficile associated diarrhea, Stevens-Johnson syndrome | 24 hr AUC/MIC | 2.4 h | bacteriostatic | ||
| Atypicals | |||||||
| Azithromycin | 500 mg q 24h | QTc Prolongation, transient hearing loss, | 24 hr AUC/MIC | biliary | 68 | 50 s ribosome | bacteriostatic |
| Levofloxacin** | 500 to 750 mg q 24h | Tendon rupture, interstitial nephritis QTC prolongation, peripheral neuropathy, monitor BUN, SCr, AST and ALT, Physicial examination: encephalopathic changes. Calcium can bind to fluoroquinolone antibiotics and make them ineffective, so it’s recommended to avoid taking calcium supplements, dairy products, or calcium-containing antacids for 2 hours before and 2 hours after taking the antibiotic | both concentration-dependent (peak:MIC), and a combination of concentration and time-dependent killing (AUC:MIC). | renal | 7 | Inhibition of topoisomerase (DNA gyrase) enzymes | bacteriocidal |
| Ciprofloxacin** | 500 to 750 mg PO q 12h | Calcium can bind to fluoroquinolone antibiotics and make them ineffective, so it’s recommended to avoid taking calcium supplements, dairy products, or calcium-containing antacids for 2 hours before and 2 hours after taking the antibiotic | both concentration-dependent (peak:MIC), and a combination of concentration and time-dependent killing (AUC:MIC). | Inhibition of topoisomerase (DNA gyrase) enzymes | bacteriocidal | ||
| Anaerobes | |||||||
| Metronidazole | 500 mg q8h | Periodic CBC, urinalysis, BUN, SCr, AST and ALT, diarrhea, Metallic taste , do not take with alcohol | 24 hr AUC/MIC | 6-14 hours | bacteriocidal | ||
| Piperacillin/Tazobactam | 3.375 g to 4.5 g every 4 to 6h | Urinalysis, BUN, SCr, AST and ALT, skin rash, Neutropenia and leukopenia, | T>MIC | Renal | 1 hr | The beta-lactamase inhibitors are recognized as substrates for the beta-lactamases produced by bacteria. This allows the actual beta-lactams to attack the bacterial cell wall by binding to penicillin binding proteins | bacteriocidal |
| Ampicillin/sulbactam | 1.5 g to 3 g every 6h | BUN, SCr, AST and ALT, skin rash, Neutropenia and leukopenia, | T>MIC | Renal | ~2hr | The beta-lactamase inhibitors are recognized as substrates for the beta-lactamases produced by bacteria. This allows the actual beta-lactams to attack the bacterial cell wall by binding to penicillin binding proteins | bacteriocidal |
| Ertapenem | 1 g daily | CBC; Vital signs post-infusion in patients with risk factors for hypersensitivity (eg, history of allergies or sensitivity to cephalosporins) (signs of anaphylaxis); Neurologic evaluation in patients developing focal tremors, myoclonus, or seizures during therapy; Signs/symptoms of toxicity (eg, rash, GI disturbances, mental status changes, seizure activity, local complications (phlebitis) | T > MIC | Renal | 4 hr | Cause rapid bacterial cell death by covalently binding to penicillin-binding proteins (PBPs) involved in the biosynthesis of mucopeptides in bacterial cell walls. Bactericidal effects result through inhibition of cellular growth and division and the loss of cell wall integrity, eventually causing cell wall lysis. The primary target is PBP 2. | bacteriocidal |
| Anti-Pseudomonals | |||||||
| Gentamicin | Per pharmacy | Ototoxicity, nephrotoxicity, Cause or exacerbate neuromuscular blockade, myasthenia gravis (rare), drug levels, urine output, BUN, serum creatinine; hearing should be tested before, during, and after treatment; particularly in those at risk for ototoxicity or who will be receiving prolonged therapy (>2 weeks). | 24-hr AUC/MIC | renal | 2-3 hrs | Inhibition of protein biosynthesis by irreversible binding of the aminoglycoside to the bacterial ribosome 30S subunit | bacteriocidal |
| Tobramycin | Per pharmacy | Ototoxicity, nephrotoxicity, Cause or exacerbate neuromuscular blockade, myasthenia gravis (rare), drug levels, urine output, BUN, serum creatinine; hearing should be tested before, during, and after treatment; particularly in those at risk for ototoxicity or who will be receiving prolonged therapy (>2 weeks). | Inhibition of protein biosynthesis by irreversible binding of the aminoglycoside to the bacterial ribosome 30S subunit | bacteriocidal | |||
| Cefepime | 2 gm IV q8h | UN, SCr, AST and ALT, skin rash, Neutropenia and leukopenia, Prothrombin time in patients with renal or hepatic impairment or poor nutritional state, as well as patients receiving a protracted course of antimicrobial therapy, and patients previously stabilized on anticoagulant therapy Cefepime competitively antagonizes the GABA receptors in the brain, leading to central overexcitation that results in confusion, myoclonus, seizures, reduced levels of consciousness, and coma | Exerts bactericidal activity via inhibition of bacterial cell wall synthesis by binding one or more of the penicillin binding proteins (PBPs). | bacteriocidal | |||
| Meropenem | 1 to 2 g IV q8h | Hepatic and renal function tests during therapy | T> MIC | Renal | 1 | Cause rapid bacterial cell death by covalently binding to penicillin-binding proteins (PBPs) involved in the biosynthesis of mucopeptides in bacterial cell walls. Bactericidal effects result through inhibition of cellular growth and division and the loss of cell wall integrity, eventually causing cell wall lysis. The primary target is PBP 2. | bacteriocidal |
| Imipenem-Cilastatin | 500 mg IV q6h or 1 g IV q8h | Hepatic and renal function tests during therapy | Renal | 1 | Cause rapid bacterial cell death by covalently binding to penicillin-binding proteins (PBPs) involved in the biosynthesis of mucopeptides in bacterial cell walls. Bactericidal effects result through inhibition of cellular growth and division and the loss of cell wall integrity, eventually causing cell wall lysis. The primary target is PBP 2. | bacteriocidal | |
| Gram Negative Agents | |||||||
| Ampicillin | 2 gm IV q 6h | anemia, thrombocytopenia, neutropenia, agranulocytosis, Jarisch-Herxheimer Reaction (fever, chills, sweating, tachycardia, hyperventilation, flushing, and myalgia), transient increases in transaminases, Periodic CBC, urinalysis, BUN, Creatinine, AST and ALT, diarrhea, skin rash Patients with mononucleosis are more likely to develop a skin rash with amoxicillin or other PCN antibiotics | T>MIC | renal | 1.2 h | Exerts bactericidal activity via inhibition of bacterial cell wall synthesis by binding one or more of the Exerts bactericidal activity via inhibition of bacterial cell wall synthesis by binding one or more of the penicillin binding proteins (PBPs). | bacteriocidal |
| Ceftriaxone | 1 gm q24h | BUN, SCr, AST and ALT, skin rash, Neutropenia and leukopenia, Prothrombin time in patients with renal or hepatic impairment or poor nutritional state, as well as patients receiving a protracted course of antimicrobial therapy, and patients previously stabilized on anticoagulant therapy, seizures, sludging in gall bladder, do not use in hyperbilirubinemic neonates, use with caution in patients with concurrent hepatic dysfunction | T>MIC | Renal, biliary | 8 | Exerts bactericidal activity via inhibition of bacterial cell wall synthesis by binding one or more of the penicillin binding proteins (PBPs). | bacteriocidal |
| Penicillins | |||||||
| Penicillin G | 3 million units q4h | Periodic CBC, urinalysis, BUN, SCr, AST and ALT, diarrhea, skin rash 20 million units of the potassium salt contains about 30 mmol of potassium, and in patients with renal insufficiency this amount can decisively aggravate potentially lethal hyperkalemia. High doses of sodium penicillin can cause urinary potassium loss, | T > MIC | Renal | 0.5 | Exerts bactericidal activity via inhibition of bacterial cell wall synthesis by binding one or more of the penicillin binding proteins (PBPs). | bacteriocidal |
| Penicillin G Benzathine (preferred agent for syphilis) | 2.4 million units IM as a single dose NO IV USE | Exerts bactericidal activity via inhibition of bacterial cell wall synthesis by binding one or more of the penicillin binding proteins (PBPs). | bacteriocidal | ||||
| Cephalexin | Exerts bactericidal activity via inhibition of bacterial cell wall synthesis by binding one or more of the penicillin binding proteins (PBPs). | bacteriocidal | |||||
| Cefdinir | Exerts bactericidal activity via inhibition of bacterial cell wall synthesis by binding one or more of the penicillin binding proteins (PBPs). | bacteriocidal | |||||
| Amoxicillin | Exerts bactericidal activity via inhibition of bacterial cell wall synthesis by binding one or more of the penicillin binding proteins (PBPs). | bacteriocidal | |||||