Drug Summary: Antibiotics (PDF)

ANTIBIOTICS AMINOGLYCOSIDES GENTAMICIN Def: bactericidal used to treat serious infections caused by Gram-negative aerobic bacilli THERAPEUTIC ACTIONS Inhibit protein synthesis in Gram-negative bact...

ANTIBIOTICS AMINOGLYCOSIDES GENTAMICIN Def: bactericidal used to treat serious infections caused by Gram-negative aerobic bacilli THERAPEUTIC ACTIONS Inhibit protein synthesis in Gram-negative bacteria Irreversibly bind to unit of bacteria ribosomes, leading to misreading of the genetic code & cell death. INDICATIONS For pseudomonas infections and a wide variety of gram-negative infections PHARMACOKINETICS Through IM, IV; rapid onset Peak of 30-90 mins; HL of 2-3 hrs, metabolized in the liver CONTRAINDICATIONS & C/Is: Known allergy to aminoglycosides; renal/hepatic dse; preexisting hearing loss; active herpes or mycobacterial infections; CAUTION myasthenia gravis or parkinsonism; lactation. Administer w/ caution during pregnancy, benefits must be weighed against potential adverse effects on the fetus. Frequent urine function tests are necessary because drugs depend on the kidney for excretion. Potential for nephrotoxicity & ototoxicity with amikacin is very high, used only if absolutely necessary Streptomycin, reserved for use in special situations (very toxic to the eighth cranial nerve and kidney. ADVERSE EFFECTS Sinusitis, dizziness, rash, fever, risk of nephrotoxicity DRUG-DRUG Have synergistic bactericidal effects when given with penicillins or cephalosporins. Avoid combining w/ potent diuretics (increases INTERACTIONS AEs). If given w/ anesthetics, nondepolarizing neuromuscular blockers, succinylcholine, or citrate anticoagulated blood, increased neuromuscular blockade with paralysis is possible. If given to patient for surgery, indicate in chart & provide extended monitoring and support after surgery CARBAPENEMS ERTAPENEM THERAPEUTIC ACTIONS Bactericidal that inhibit cell membrane synthesis in susceptible bacteria, leading to cell death INDICATIONS Treatment of community-acquired pneumonia, complicated GU infections, complicated intra-abdominal infections, skin-and-skin structure infections, and acute pelvic infections caused by susceptible bacteria PHARMACOKINETICS Given IV or IM, once a day for 5 to 14 days, depending on the infection. Rapid onset Peak of 30-120 mins. HL 4 hrs, excreted unchanged in urine CONTRAINDICATIONS & C/Is: Known allergy, seizure disorders, meningitis, lactation CAUTION Use caution during pregnancy. Test urine function regularly (depend on kidney for excretion & toxic to kidney). Ertapenem & meropenem-vaborbactam - not recommended in patients younger than 18 years of age. ADVERSE EFFECTS Headache, dizziness, nausea, vomiting, pseudomembranous colitis, rash, pain at injection site DRUG-DRUG Consider an alternative treatment if patient is on valproic acid. Combination of these drugs can cause serum valproic acid levels INTERACTIONS to fall and increase the risk of seizures. CEPHALOSPORINS CEFACLOR THERAPEUTIC ACTIONS Inhibits the synthesis of bacterial cell walls, causing cell death in susceptible bacteria INDICATIONS For respiratory tract infections, skin infections (dermatologic), UTI, otitis media (middle ear), typhoid fever, anthrax exposure PHARMACOKINETICS Via oral, peak of 20-60 mins, duration of 8-10 hrs HL of 30-60 mins, excreted unchanged in urine CONTRAINDICATIONS & C/Is: Allergies to cephalosporins or penicillins because cross-sensitivity is common. CAUTION Cautions: Hepatic or renal impairment - cephalosporins are toxic to kidneys & could interfere w/ metabolism & excretion. Pregnant or lactation – potential effects on fetus/infant not known; use only if benefits outweigh risk. ADVERSE EFFECTS Nausea, vomiting, diarrhea, rash, superinfections, bone marrow depression, risk for pseudomonas colitis DRUG-DRUG Cephalosporins with aminoglycosides increases the risk for nephrotoxicity. Frequently monitor patients receiving this INTERACTIONS combination, & evaluate serum blood urea nitrogen (BUN) & creatinine levels. Oral anticoagulants + cephalosporins - may increase bleeding. Monitor blood loss (e.g., bleeding gums, easy bruising), may reduce anticoagulant dose. Avoid alcohol for up to 72 hours after discontinuation the drug to prevent a disulfiram-like reaction, which results in unpleasant symptoms such as flushing, throbbing headache, nausea and vomiting, chest pain, palpitations, dyspnea, syncope, vertigo, blurred vision, and, in extreme reactions, cardiovascular collapse, convulsions, or even death. FLUOROQUINOLONES CIPROFLOXACIN THERAPEUTIC ACTIONS Interferes with DNA replication in susceptible Gram-negative bacteria, preventing cell reproduction INDICATIONS Treatment of respiratory, dermatological, UTI, ear, eye, bone and joint infection; treatment after anthrax exposure, typhoid fever, plague PHARMACOKINETICS ORAL - onset varies, peak of 60-90 min, duration of 4-5 hrs IV - onset in 10 mins, peak of 30 mins, duration of 4-5 hrs HL of 3.5-4 hrs, metabolized in the liver, excreted via bile and urine CONTRAINDICATIONS & C/Is: Allergy to drug, pregnancy, lactation. CAUTION Cautions: presence of renal dysfunction (could interfere w/ metabolism & excretion of drug), & seizures (exacerbated by drugs’ effects on cell membrane channels). Not recommended for use in patients younger than 18 (drug is associated with lesions in developing cartilage). ADVERSE EFFECTS Headache, dizziness, hypotension nausea, vomiting, diarrhea, fever, rash DRUG-DRUG Effect decreased if taken concurrently w/ iron salts, sucralfate, mineral supplements, or antacids. INTERACTIONS If drug combination is necessary, administer 2 agents by at least 4 hours apart. Fluoroquinolones taken w/ drugs that increase the QTc interval- severe- to-fatal cardiac reactions are possible & should be avoided, but if used, patients should be hospitalized with continual cardiac monitoring. Fluoroquinolones w/ theophylline leads to increased theophylline levels coz 2 drugs use similar metabolic pathways. Theophylline dose should be decreased by one-half and serum theophylline levels monitored carefully. Fluoroquinolones w/ nonsteroidal antiinflammatory drugs- increased risk of CNS stimulation is possible. closely monitor patients, especially those who have a history of seizures or CNS problems. Fluoroquinolone with corticosteroids- can increase risk of tendonitis & tendon rupture. Instruct patient to report any tendon pain or weakness. PENICILLINS AND AMOXICILLIN PENICILLINASE-RESISTANT ANTIBIOTICS THERAPEUTIC ACTIONS Inhibits synthesis of the cell wall in susceptible bacteria, causing cell death INDICATIONS For infections caused by susceptible strains of bacteria; treatment of helicobacter infections as part of combination therapy. Tow off label uses include post exposure prophylaxis for anthrax and endocarditis PHARMACOKINETICS Oral, reaching peak levels in 1 hour. Sensitive to gastric acid levels in stomach & should be taken on empty stomach to ensure adequate absorption. Onset varies. Peak of 1hr, duration of 6-8 hrs Excreted unchanged in urine, making renal function an important factor in safe use of the drug, HL of 1-1.4 hrs CONTRAINDICATIONS & C/Is: allergies to penicillin or cephalosporins or other allergens. CAUTION Cautions: renal disease (lowered doses are necessary because excretion is reduced). Although there’s no adequate studies of use during pregnancy, use in patients who are Use in pregnant or lactating mothers- only when benefit is clear. Diarrhea & superinfections may occur in the infant. Perform culture and sensitivity tests ADVERSE EFFECTS Nausea, vomiting, diarrhea, glossitis, stomatitis, bone marrow suppression, rash, fever, superinfections, lethargy DRUG-DRUG Combinations that should be avoided: INTERACTIONS Penicillins & penicillinase-resistant antibiotics with tetracyclines- will decrease penicillin’s effectiveness. Penicillin doses should be raised if cannot be avoided, which could increase the occurrence of adverse effects. Parenteral forms of penicillins & penicillinase- resistant drugs with any of the parenteral aminoglycosides, inactivation of the aminoglycosides occurs. SULFONAMIDES COTRIMOXAZOLE THERAPEUTIC ACTIONS Blocks two consecutive steps in protein and nucleic acid production, leading to inability for cells to multiply INDICATIONS For UTI, acute otitis media in children, exacerbations of chronic bronchitis in adults, traveler’s diarrhea in adults, pneumocystis jiroveci pneumonia when caused by susceptible strains of bacteria PHARMACOKINETICS Combination of sulfamethoxazole & trimethoprim. Orally, rapidly absorbed; peak: 1-4 hrs. Half-life: 8-10 hrs, excreted in urine CONTRAINDICATIONS & C/Is: allergy to: Any sulfonamide, Sulfonylureas, Thiazide diuretics (due to cross-sensitivities). Pregnancy (risk of birth defects CAUTION and kernicterus). Lactation (risk of kernicterus, diarrhea, and rash in the infant Cautions: Renal disease or history of kidney stones (risk of increased toxic effects) Elderly (increased incidence of CNS effects and safety concerns) ADVERSE EFFECTS GIT: Nausea, vomiting, diarrhea, hepatocellular necrosis, hematouria, bone marrow suppression, rash, urticaria, photophobia, fever and chills DRUG-DRUG Antidiabetic Agents- increased risk of hypoglycemia when combined with: Tolbutamide, tolazamide, glyburide, glipizide, INTERACTIONS chlorpropamide. Requires monitoring and possible dose adjustment of the antidiabetic agent during and after sulfonamide therapy. Cyclosporine- increased risk of nephrotoxicity. Requires close monitoring; D/C sulfonamide if renal dysfunction occurs. TETRACYCLINE TETRACYCLINE THERAPEUTIC ACTIONS Inhibit protein synthesis in bacteria; Prevent bacteria from multiplying; Potential toxicity to humans at high concentrations due to similarity to human proteins. INDICATIONS For infections caused by susceptible strains of bacteria, acne, and when penicillin is contraindicated for eradication of susceptible organisms PHARMACOKINETICS Oral - onset varies, peak of 2-4 hrs Topical - minimal absorption occurs, peak of 2-4 hrs HL of 6-12 hrs, excreted unchanged in urine CONTRAINDICATIONS & C/Is: Allergy to tetracyclines or tartrazine. Pregnancy & lactation (due to effects on developing bones and teeth). CAUTION Ophthalmic preparation in patients with fungal, mycobacterial, or viral ocular infections (risk of exacerbating infection by disrupting normal flora) Cautions: Children younger than 8 years of age (potential damage to developing bones and teeth). Patients with hepatic or renal dysfunction (due to concentration in bile and excretion in urine). ADVERSE EFFECTS Nausea, vomiting, diarrhea, glossitis, discoloring and inadequate calcification of primary teeth of fetus or secondary teeth in children, bone marrow suppression, photosensitivity, superinfections, rash, local irritation (topical) DRUG-DRUG Effectiveness of penicillin G decreases when taken with tetracyclines. Increase the dose of penicillin G if used in combination with INTERACTIONS tetracyclines. Digoxin toxicity rises when tetracyclines are taken concurrently. Administer on an empty stomach 1 hour before or 2 to 3 hours after any meal or other medication. ANTIMYCOBACTERIALS ISONIAZID THERAPEUTIC ACTIONS Interferes with lipid and nucleic acid synthesis in actively growing tubercle bacilli INDICATIONS Treatment of TB as part of combination therapy, prophylactic treatment of household members of pt diagnosed with TB PHARMACOKINETICS Well absorbed from the GI tract when taken orally, onset varies, peak of 1-2 hrs, duration of 24 hrs Metabolized in the liver and excreted in the urine with HL of 1-4 hrs CONTRAINDICATIONS & Contraindicated for patients with known allergies to these agents. CAUTION Not recommended for those with severe renal or hepatic failure or severe CNS dysfunction. Pregnancy is a caution due to potential adverse effects on the fetus; if necessary, a regimen of isoniazid, ethambutol, and rifampin is considered safest. ADVERSE EFFECTS Peripheral neuropathies, nausea, vomiting, hepatitis, bone marrow suppression, fever, local irritation at injection sites, gynecomastia, lupus syndrome DRUG-DRUG Increased risk of toxic liver reactions when rifampin and INH are combined. Decreased effectiveness due to increased INTERACTIONS metabolism when rifampin or rifabutin is combined with various other drugs (e.g., quinidine, metoprolol, oral contraceptives). Bedaquiline users should avoid other drugs that prolong the QTc interval. Close monitoring and dose adjustments required for patients on these drug combinations. KETOLIDES TELITHROMYCIN THERAPEUTIC ACTIONS Binds to bacterial ribosomes, altering protein function and leading to bacterial cell death INDICATIONS Effective against several resistant strains, including: S. pneumoniae (including multidrug-resistant strains), H. influenzae, M. catarrhalis, Chlamydophila pneumoniae, & M. pneumoniae. Approved for treating mild to moderate community-acquired pneumonia PHARMACOKINETICS Oral, rapid onset, peak at 0.5-4 hrs HL of 10 hours, metabolized in the liver, excreted in feces and urine CONTRAINDICATIONS & Contraindicated with: CAUTION Allergy to the drug or macrolide antibiotics. Known congenital prolonged QT interval, bradycardia, or proarrhythmic conditions (e.g., hypokalemia). Concurrent use of pimozide, cardiac antiarrhythmics, simvastatin, atorvastatin, or lovastatin. Myasthenia  gravis (due to risk of respiratory failure, black box warning). Use with caution in: Renal or hepatic impairment. Pregnant and lactating patients ADVERSE EFFECTS Headache, dizziness, nausea, vomiting, pseudomembranous colitis, superinfections DRUG-DRUG Avoid combinations with: Pimozide, simvastatin, lovastatin, atorvastatin (risk of serious adverse effects). INTERACTIONS Monitor closely if combined with: Digoxin and metoprolol (risk of increased serum levels). Avoid or substitute other antibiotics if combined with: Rifampin, phenytoin, carbamazepine, or phenobarbital (risk of decreased telithromycin levels). Separate doses by at least 1 hour if combined with theophylline (risk of increased GI toxicity). LINCOSAMIDES CLINDAMYCIN THERAPEUTIC ACTIONS Target bacterial protein synthesis, similar to other antibiotics. INDICATIONS For infections caused by bacteria (anaerobes); useful in septicemia and chronic bone and joint infections PHARMACOKINETICS Oral - onset varies, peak of 1-2 hrs, duration 8-12 hrs IM - onset within 20-30 mins, peak of 1-3 hrs, same duration IV - immediate onset, peak in minutes, same duration Topical - minimal absorption HL of 2 to 3 hours, metabolized in the liver, excreted in the urine and feces CONTRAINDICATIONS & Use with caution in patients with hepatic or renal impairment. CAUTION Use during pregnancy and lactation only if the benefits outweigh the risks. ADVERSE EFFECTS Nausea, vomiting, diarrhea, pseudomembranous colitis, bone marrow suppression DRUG-DRUG None mentioned INTERACTIONS LIPOGLYCOPEPTIDES TELEVANCIN THERAPEUTIC ACTIONS Affects bacterial cell wall synthesis, leading to disruption of cell membrane function and bacterial cell death INDICATIONS Treatment of complicated skin and skin structure infections PHARMACOKINETICS Available as IV. rapid onset, peak at the end of infusion 8-9.5 hrs HL, unknown site of metabolism, excreted via urine CONTRAINDICATIONS & Contraindicated with known allergy to the drug. CAUTION Not recommended for pregnant or lactating patients due to potential toxic effects. Telavancin has a black box warning for serious fetal risk; contraceptive measures are urged. Culture and sensitivity testing is necessary to ensure appropriate use. ADVERSE EFFECTS Nausea, vomiting, diarrhea, taste alterations, QT prolongation, nephrotoxicity, foamy urine DRUG-DRUG Increased risk of prolonged QT interval and arrhythmias when combined with other QTprolonging drugs; ECG monitoring INTERACTIONS recommended. Increased risk of nephrotoxicity when combined with nephrotoxic drugs; renal function should be monitored. MACROLIDES ERYTHROMYCIN THERAPEUTIC ACTIONS may be bactericidal or bacteriostatic, affecting bacterial protein synthesis by binding to ribosomes. INDICATIONS For respiratory, dermatological, UTI and GI infections PHARMACOKINETICS Oral - onset in 1-2 hrs, peak within 1-4 hrs IV, rapid onset, peak in 1 hr HL of 3 to 5 hrs, metabolized in the liver, excreted in bile and urine CONTRAINDICATIONS & Contraindicated in patients with a known allergy to macrolides (cross-sensitivity occurs). Ocular preparations contraindicated for CAUTION viral, fungal, or mycobacterial eye infections. Use with caution in: Patients with hepatic or renal dysfunction; Pregnant and lactating women (macrolides in breast milk can cause diarrhea and superinfections in infants). ADVERSE EFFECTS Abdominal cramping, vomiting, diarrhea, rash, superinfections, liver toxicity, pseudomonas colitis, possibly hearing loss DRUG-DRUG Digoxin: Increased serum levels when taken with macrolides; monitor and adjust dosage. INTERACTIONS Oral anticoagulants, theophyllines, carbamazepine, corticosteroids: Effects increase due to metabolic changes in the liver; may require dose reduction and careful monitoring. Cycloserine: Increased serum levels, risk of renal toxicity; avoid combination if possible. DRUG-FOOD Food decreases absorption of oral macrolides. INTERACTIONS Take macrolides on an empty stomach with a full glass of water 1 hour before or 2-3 hours after meals. OXAZOLIDINONES LINEZOLID THERAPEUTIC ACTIONS Binds to ribosomes within bacterial cell INDICATIONS For infections caused by resistant strains, pneumonias, skin and skin structure infections, diabetic foot infections PHARMACOKINETICS Oral and IV, rapid onset, peak in 1-2 hrs (oral) and 90 mins (IV) HL of 5 hours, metabolized in liver, excreted in urine CONTRAINDICATIONS & Contraindicated with: Known allergy to the drug or components; Phenylketonuria (with oral suspension of linezolid); Patients on CAUTION MAO inhibitors (due to reversible MAO inhibitor effect); Breastfeeding women (drug enters breast milk, can be toxic). Use with caution in patients with: Hepatic impairment, pheochromocytoma, hypertension, hyperthyroidism, bone marrow suppression. During pregnancy (effects on fetus unknown). ADVERSE EFFECTS Headache, dizziness, vomiting, diarrhea, potential for pseudomembranous colitis, thrombocytopenia DRUG-DRUG Increased risk of hypertension with drugs that raise blood pressure. INTERACTIONS Increased risk of bleeding and thrombocytopenia with NSAIDs and platelet inhibitors. Risk of serotonin syndrome with serotogenic drugs; avoid combination unless necessary. Serotonergic drugs should be stopped 2 weeks before starting oxazolidinones. DRUG-FOOD Avoid large amounts of tyramine-containing foods due to the risk of serious or life-threatening hypertension. INTERACTIONS MONOBACTAM ANTIBIOTIC AZTREONAM THERAPEUTIC ACTIONS Effective against Gram-negative enterobacteria. Not effective against Gram-positive or anaerobic bacteria; Disrupts bacterial cell wall synthesis, causing cell death. INDICATIONS For lower respiratory, dermatological, UTI, intra-abdominal, gynecological infections PHARMACOKINETICS IM - onset varies, peak in 60-90 mins, 6-8 hrs duration IV- immediate onset, 30 mins peak, same duration HL 1.5 to 2 hrs, excreted unchanged in urine CONTRAINDICATIONS & Contraindicated in patients with known allergy to aztreonam. CAUTION Use with caution in patients with: History of acute allergic reaction to penicillins or cephalosporins (possible cross-reactivity), Renal or hepatic dysfunction (may interfere with drug clearance and excretion), Pregnant and lactating women (potential adverse effects on fetus or neonate). ADVERSE EFFECTS Nausea, vomiting, diarrhea, rash, superinfections, anaphylaxis, local discomfort DRUG-DRUG Incompatible in solution with nafcillin, cephradine, and metronidazole. INTERACTIONS