Drugs for bacterial infections Flashcards
penicillin G
Therapeutic Class:
Antibacterial
Pharmacologic Class:
Cell wall inhibitor; natural penicillin
Actions and Uses:
Similar to penicillin V, penicillin G is a drug of choice against streptococci, pneumococci, and staphylococci organisms that do not produce beta-lactamase and are shown to be susceptible by C&S testing. It is also a medication of choice for gonorrhea and
syphilis caused by susceptible strains. Penicillin G is available as either a potassium or sodium salt; there is no difference therapeutically between the two salts. Penicillin G benzathine (Bicillin) and penicillin G procaine are longer-acting parenteral
salts of the drug.
Risks:
observe for possible allergic reactions
for 30 minutes, especially following the first dose.
Do not mix penicillin and aminoglycosides in the same I V solution.
Give IV medications 1 hour apart to prevent interactions.
Pregnancy category B.
Pharmacokinetics:
onset- 15-30 min IM (IV is immediate)
peak- 30min
duration- 4-6 hrs
Adverse Effects:
Diarrhea, nausea, and vomiting are the most common adverse effects and can be serious in
children and older adults. Pain at the injection site may occur, and superinfections are possible. Anaphylaxis is the most serious adverse effect. While most allergic reactions to penicillin occur within minutes
after administration, late hypersensitivity reactions may occur several weeks into the regimen.
Contraindications:
hypersensitivity to a drug in the penicillin class. Because penicillin G is excreted extensively by the kidneys, the drug should be used with caution in patients with severe renal disease.
Interaction–>
drug to drug: decrease effectiveness of oral contraceptives. Colestipol will decrease absorption of penicillin
lab test: gives positive coombs test and false urinary or serum proteins
herbal/food: dk
treatment overdose: no
cefazolin
Therapeutic Class:
Antibacterial
Pharmacologic Class:
Cell wall inhibitor: first-generation cephalosporin
Actions and Uses:
Cefazolin is a beta-lactam antibiotic used for the treatment and prophylaxis of bacterial infections, particularly those that are caused by susceptible gram-positive organisms. Treats infections of the respiratory tract, urinary tract, skin structures, biliary tract, bones, and joints. It has also been useful in the pharmacotherapy of genital infections, septicemia, and endocarditis. Cefazolin is not effective against MRSA.
Risks:
Administer IM injections deep into a large muscle mass to prevent injury to surrounding tissues.
Pregnancy category B.
pharmacokinetics:
onset- 1-2hrs IM ( 5 min IV)
peak- 30 min
duration- 90-135min
adverse effects:
well tolerated by most patients. Rash and diarrhea are the most common adverse effects, and superinfections are likely when the antibiotic is used for prolonged periods. Severe hypersensitivity reactions are rare although potentially fatal. Pain and
phlebitis can occur at IM injection sites. Seizures are a rare.
Contraindications:
hypersensitivity to cephalosporins or penicillins. Because cefazolin is extensively excreted by the kidneys, the drug should be used with caution in
patients with (CKD).
interaction–>
drug to drug: with nephrotoxic drugs (amino glycosides/vancomycin) increases risk of nephrotoxicity
labs: false positive coombs test
herbal/food: dk
treat overdose: no
tetracycline
Therapeutic Class:
Antibacterial
Pharmacologic Class:
Tetracycline; protein synthesis inhibitor
Actions and Uses:
effective against f gram-positive and
gram-negative organisms, including Chlamydia, Rickettsiae, and Mycoplasma. Effective against H. pylori in the treatment of peptic ulcer disease.
its administered PO, has a short half-life that may
require administration 4 times per day. Topical and oral preparations are available for treating acne. An IM preparation is available; however,
causes intense pain at the injection site.
Risks:
Administer oral drug with a full glass of water to decrease esophageal and GI irritation.
Administer antacids and tetracycline 1 to 3 hours apart.
Pregnancy category D.
pharmacokinetics:
onset- 1-2hrs
peak- 2-4hrs
duration- 12hrs
Adverse Effects:
Being a broad-spectrum antibiotic.Affects
vaginal, oral, and intestinal flora and cause superinfections. Tetracycline irritates the GI mucosa and may cause nausea, vomiting, epigastric burning, and diarrhea. Diarrhea may be severe enough to cause
discontinuation of therapy. Other common side effects include discoloration of the teeth and photosensitivity.
Contraindications:
patients with hypersensitivity to drugs in
this class. The drug should not be used during the second half of pregnancy, in children 8 years or younger, and in patients with severe
renal or hepatic impairment.
Interactions–>
drug to drug: milk products, iron supplements, magnesium, antacids
labs: increase lab values of BUN, AST, ALT, bilirubin
herbal/food: dairy products interferes with the absorption
treatment overdose: no
erythromycin
Therapeutic Class:
Antibacterial
Pharmacologic Class:
Macrolide; protein synthesis inhibitor
Actions and Uses:
its inactivated by stomach acid and is thus formulated as coated, acid-resistant tablets or capsules that dissolve in the small intestine. Its main application is for patients who are unable to tolerate penicillins or who may have a penicillin-resistant infection. It
has a spectrum similar to that of the penicillins and is effective against most gram-positive bacteria. It is sometimes used to treat susceptible infections by Bordetella pertussis (whooping cough),
Legionella pneumophila (Legionnaire disease), M. pneumoniae, and Corynebacterium diphtheriae (diphtheria).
Risks:
Administer oral drug on an empty stomach with a full glass of water.
mix medication well.
Do not give with or immediately before or after fruit juices.
Pregnancy category B.
pharmacokinetics:
onset- 1hr
peak- 1-4 hrs
duration- 1.5-2 hrs
Adverse Effects
nausea, abdominal cramping, and vomiting. Concurrent administration with food reduces these symptoms. Hearing loss, vertigo, and dizziness may be experienced using high doses, particularly in older adults
and in those with impaired hepatic or renal excretion. High doses of IV erythromycin may be cardiotoxic and pose a risk for potentially fatal dysrhythmias.
Contraindications:
contraindicated in patients with hypersensitivity to drugs in the macrolide class and for those who are taking terfenadine, astemizole, or cisapride.
Interactions–>
drug to drug: Anesthetics, azole antifungals, and
anticonvulsants may interact to cause serum drug levels of erythromycin to rise and result in toxicity. This drug interacts with cyclosporine, increasing the risk for nephrotoxicity. It may increase the effects of warfarin. The concurrent use of erythromycin with lovastatin or simvastatin is not recommended because it may increase the risk of muscle toxicity. Ethanol use may decrease the absorption of erythromycin.
labs: interfere with AST and give urinary catecholamine values.
herbal/food: Grapefruit juice may increase the bioavailability of erythromycin. St. John’s wort decrease
effectiveness of erythromycin.
treat for overdose: no
trimethoprim-sulfamethoxazole
Therapeutic Class:
Antibacterial
Pharmacologic Class:
Sulfonamide; folic acid inhibitor
Actions and Uses:
The fixed-dose combination of sulfamethoxazole (SMZ) with the anti-infective trimethoprim (TMP) is most frequently prescribed for
the pharmacotherapy of UTIs. It is also approved for the treatment of Pneumocystis carinii pneumonia, shigella infections of the small bowel, and for acute episodes of chronic bronchitis. Oral and
IV preparations are available. Both SMZ and TMP are inhibitors of the bacterial metabolism of
folic acid.
Risks:
Administer oral dosages with a full glass of water.
Pregnancy category C.
pharmacokinetics:
onset- 30-60 minutes
peak- 1-4hrs
duration- 8-13 hrs
Adverse effects:
Nausea and vomiting are the most frequent adverse effects of TMP-SMZ therapy. Hypersensitivity is relatively common and usually manifests as
skin rash, itching, and fever. This medication should be used cautiously in patients with CKD because crystalluria, oliguria, and renal failure have
been reported. Avoid direct sunlight during therapy due to hypersensitivity
Contraindications:
Patients with documented megaloblastic anemia due to folate deficiency should not receive this drug. Pregnant women at term and nursing mothers
should not take this drug because sulfonamides may cross the placenta and are excreted in milk and may cause kernicterus. Trimethoprim decreases potassium excretion and should be used
with caution in patients with hyperkalemia.
interactions—>
drug to drug: enhance the effects of certain
anticoagulants, resulting in serious or life-threatening
interactions. These drugs may also increase methotrexate toxicity. By decreasing the hepatic metabolism of phenytoin, TMP-SMZ may cause phenytoin toxicity. TMP-SMZ exerts a potassium-sparing effect on the nephron and should be used
with caution with diuretics such as spironolactone (Aldactone) to prevent hyperkalemia.
labs:dk
herbal/food: potassium supplements
treat overdose: if signs of bone marrow suppression, GIVE 5-15mg of leucovorin should be given daily
Gentamicin
Therapeutic Class:
Antibacterial
Pharmacologic Class:
Aminoglycoside; protein synthesis inhibitor
Actions and Uses:
broad-spectrum, bactericidal antibiotic usually prescribed for serious urinary, respiratory, nervous, or GI infections when less toxic antibiotics are contraindicated. Activity includes Enterobacter, E. coli,
Klebsiella, Citrobacter, Pseudomonas, and Serratia. Gentamicin is
effective against a few gram-positive bacteria, including some strains of M RSA. It may be given concurrently with penicillins or cephalosporins to
improve bacterial kill and to delay resistance. This drug is not absorbed by
the oral route. A topical formulation (Genoptic) is available for infections of
the external eye.
Risks:
* For I M administration, inject deep into a large muscle.
* Use only I M and I V drug solutions that are clear and
colorless or slightly yellow. Discard discolored solutions or
those that contain particulate matter.
* Withhold the drug if the peak serum level lies above the
normal range of 5–10 m c g/m L.
* Pregnancy category C.
Pharmacokinetics:
onset- rapid
peak- 1-2hrs
duration- 8-12hrs
Adverse effects:
Rash, nausea, vomiting, and fatigue. With other aminoglycosides, certain
adverse effects may be severe. Resistance to gentamicin is increasing.
BLACK BOX WARNING: Neurotoxicity (paresthesia, muscle twitching and seizures) may manifest as ototoxicity and produce a loss of hearing or balance, which may become permanent with continued use. Tinnitus, vertigo, and headaches are early signs of ototoxicity. Risk if higher in CKD patients. Neuromuscular weakness. reduce kidney function.
contraindications:
hypersensitivity to drugs in the aminoglycoside class. monitor carefully patients with impaired renal function or those with preexisting hearing loss.
Interactions—>
drug to drug: ototoxicity increases if the patient is currently taking amphotericin B, furosemide, aspirin, bumetanide, ethacrynic acid, cisplatin, or paromomycin.
Concurrent use with amphotericin B, capreomycin, cisplatin,
polymyxin B, or vancomycin increases the risk of nephrotoxicity.
Lab Tests: Gentamicin may increase values of the following: serum bilirubin, serum creatinine, serum lactate
dehydrogenase (L D H), BUN, AST, or ALT; may decrease
values for the following: serum calcium, sodium, or potassium.
Herbal/Food: Unknown
Treatment of Overdose: There is no specific treatment for
overdose.
ciprofloxacin
Therapeutic Class:
Antibacterial
Pharmacologic Class: Fluoroquinolone; bacterial D N A synthesis inhibitor
Actions and Uses
second-generation fluoroquinolone, is the most widely prescribed drug in this class. By inhibiting bacterial DNA gyrase,
ciprofloxacin affects bacterial replication and DNA repair. More effective
against gram-negative than gram-positive organisms, it is prescribed for
UTI, sinusitis, pneumonia, skin, bone and joint infections, infectious diarrhea, and certain eye infections. The drug is rapidly absorbed after PO administration and is distributed to most body tissues. admin. are PO, IV, OPTH, Otic. ER proquin XR is admin for only 3 days and for bladder infections
Risks:
* Administer at least 4 hours before antacids and ferrous sulfate.
* Pregnancy category C.
Pharmacokinetics:
onset- Rapid
peak- 1-2hrs
duration- 12hrs
Adverse Effects
serious adverse effects are uncommon. Nausea, vomiting, and diarrhea 20% Ciprofloxacin may be administered with food to diminish adverse GI effects. The patient should not, however, take this
drug with antacids or mineral supplements because drug absorption will
be diminished. Some patients report phototoxicity, headache, and
dizziness.
Black Box Warning: Tendinitis and tendon rupture may occur in patients
of all ages. Risk is especially high in patients over age 60; in kidney,
heart, and lung transplant recipients; and in those receiving concurrent
corticosteroid therapy.
Contraindications:
Ciprofloxacin is contraindicated in patients with hypersensitivity to drugs in the fluoroquinolone class. The drug should be
discontinued if the patient experiences pain or inflammation of a tendon
because tendon ruptures have been reported.
Interactions—>
Drug–Drug: Concurrent administration with warfarin may increase
anticoagulant effects and result in bleeding. Antacids, iron salts, and
sucralfate decrease the absorption of ciprofloxacin. Concurrent
administration of ciprofloxacin with strong CYP3A4 inhibitors, such as
clarithromycin, azole antifungals, or ritonavir, may result in hypotension
and syncope.
Lab Tests:
Ciprofloxacin may increase values of ALT, AST, serum creatinine, and BUN.
Herbal/Food:
Ciprofloxacin can increase serum levels of
caffeine; caffeine consumption should be restricted to prevent excessive nervousness, anxiety, or tachycardia.
Dairy products or calcium-fortified drinks can decrease the absorption of ciprofloxacin.
Treatment of Overdose:
There is no specific treatment for overdose.
ciprofloxacin
Therapeutic Class:
Antibacterial
Pharmacologic Class: Fluoroquinolone; bacterial D N A synthesis inhibitor
Actions and Uses
second-generation fluoroquinolone, is the most widely prescribed drug in this class. By inhibiting bacterial DNA gyrase,
ciprofloxacin affects bacterial replication and DNA repair. More effective
against gram-negative than gram-positive organisms, it is prescribed for
UTI, sinusitis, pneumonia, skin, bone and joint infections, infectious diarrhea, and certain eye infections. The drug is rapidly absorbed after PO administration and is distributed to most body tissues. admin. are PO, IV, OPTH, Otic. ER proquin XR is admin for only 3 days and for bladder infections
Risks:
* Administer at least 4 hours before antacids and ferrous sulfate.
* Pregnancy category C.
Pharmacokinetics:
onset- Rapid
peak- 1-2hrs
duration- 12hrs
Adverse Effects
serious adverse effects are uncommon. Nausea, vomiting, and diarrhea 20% Ciprofloxacin may be administered with food to diminish adverse GI effects. The patient should not, however, take this
drug with antacids or mineral supplements because drug absorption will
be diminished. Some patients report phototoxicity, headache, and
dizziness.
Black Box Warning: Tendinitis and tendon rupture may occur in patients
of all ages. Risk is especially high in patients over age 60; in kidney,
heart, and lung transplant recipients; and in those receiving concurrent
corticosteroid therapy.
Contraindications:
Ciprofloxacin is contraindicated in patients with hypersensitivity to drugs in the fluoroquinolone class. The drug should be
discontinued if the patient experiences pain or inflammation of a tendon
because tendon ruptures have been reported.
Interactions—>
Drug–Drug: Concurrent administration with warfarin may increase
anticoagulant effects and result in bleeding. Antacids, iron salts, and
sucralfate decrease the absorption of ciprofloxacin. Concurrent
administration of ciprofloxacin with strong CYP3A4 inhibitors, such as
clarithromycin, azole antifungals, or ritonavir, may result in hypotension
and syncope.
Lab Tests:
Ciprofloxacin may increase values of ALT, AST, serum creatinine, and BUN.
Herbal/Food:
Ciprofloxacin can increase serum levels of
caffeine; caffeine consumption should be restricted to prevent excessive nervousness, anxiety, or tachycardia.
Dairy products or calcium-fortified drinks can decrease the absorption of ciprofloxacin.
Treatment of Overdose:
There is no specific treatment for overdose.
