Unit 12: Medications for Infection

How do antimicrobial medications achieve 'selective toxicity' without harming host cells?

They target structures unique to microbes, such as bacterial cell walls or specific ribosomal subunits.

What is the priority nursing action before administering the first dose of a prescribed antibiotic to a client with a wound infection?

Obtain a specimen for culture and sensitivity to identify the causative organism.

Which type of resistance occurs when an antibiotic destroys normal flora, allowing a new, difficult-to-treat infection to emerge?

Superinfection

How do bacteriostatic medications differ from bactericidal medications in their effect on the immune system?

Bacteriostatic drugs slow growth so that host phagocytic cells can destroy the bacteria, whereas bactericidal drugs are directly lethal.

To determine the lowest concentration of an antibiotic that inhibits bacterial growth completely without killing it, the technician measures the _____.

Minimum inhibitory concentration (MIC)

Why are infants at a higher risk for antimicrobial toxicity compared to healthy adults?

Undeveloped kidney and liver function lead to slower excretion and metabolism of the medication.

A nurse is caring for a client with meningitis. Why is the choice of antimicrobial specifically restricted in this condition?

The medication must be able to cross the blood-brain barrier to reach the cerebrospinal fluid.

What is the specific risk of administering sulfonamides to a client in their third trimester of pregnancy?

It can cause kernicterus, a severe neurologic disorder, in the newborn.

Which specific adverse effect is associated with gentamicin use during pregnancy?

Congenital hearing loss in the infant.

A client allergic to penicillin is prescribed cephalexin. What is the primary concern for the nurse regarding this prescription?

There is a risk of cross-sensitivity between penicillins and cephalosporins.

How long should a nurse observe a client following the parenteral administration of a penicillin?

30 minutes

What is the interaction between penicillin and aminoglycosides when mixed in the same IV solution?

The penicillin inactivates the aminoglycoside.

Which specific patient education should be provided to a client taking amoxicillin regarding birth control?

Use an additional non-hormonal contraceptive method, as penicillins can decrease the effectiveness of oral contraceptives.

A client on high doses of intravenous penicillin G potassium should be monitored for which electrolyte imbalance?

Hyperkalemia

Which generation of cephalosporins is the only one effective against MRSA?

Fifth generation (e.g., ceftaroline)

A client taking cefotetan consumes alcohol and experiences flushing and vomiting. This is known as a _____.

Disulfiram-like reaction

Why should ceftriaxone not be administered concurrently with IV solutions containing calcium?

The combination can cause life-threatening precipitates to form in the solution.

A client receiving a cephalosporin reports frequent, watery stools. What serious complication should the nurse suspect?

Antibiotic-associated pseudomembranous colitis (C. difficile).

Which laboratory values must be monitored for a client receiving cefotetan due to the risk of bleeding?

Prothrombin time (PT) and bleeding time.

Why are carbapenems generally reserved for clients who cannot be treated with narrow-spectrum antibiotics?

To delay the emergence of bacterial resistance.

A client taking imipenem-cilastatin is also on valproic acid. What clinical finding should the nurse prioritize monitoring?

Seizure activity, as carbapenems can reduce blood levels of valproic acid.

What is the recommended infusion time for vancomycin to prevent 'Red Man Syndrome'?

At least 60 minutes

A nurse is monitoring a client on vancomycin. What baseline and periodic laboratory test is essential to prevent renal failure?

Creatinine (or kidney function tests) and vancomycin trough levels.

How does the administration of vancomycin change when treating C. difficile versus a systemic infection?

It is administered orally or rectally for C. difficile, as it is poorly absorbed from the GI tract for systemic use.

Why should tetracyclines be avoided in children under 8 years of age?

They cause permanent yellow or brown tooth discoloration and hypoplasia of tooth enamel.

A client is taking tetracycline for acne. What skin-related instruction is essential?

Wear protective clothing and sunscreen ($SPF \ge 30$) due to photosensitivity.

What is the primary reason for instructing a client not to take tetracycline just before bedtime?

To reduce the risk of esophageal ulceration.

How does the ingestion of milk or antacids affect the absorption of tetracyclines?

They form nonabsorbable chelates, significantly reducing the medication's absorption.

Which macrolide antibiotic is associated with the serious complication of prolonged QT intervals and sudden cardiac death?

Erythromycin

What sensory assessment is a priority for a client receiving high-dose erythromycin therapy?

Hearing acuity, due to the risk of ototoxicity.

Which laboratory test should the nurse monitor for a client taking both erythromycin and warfarin?

PT or INR, as erythromycin inhibits warfarin metabolism, increasing the risk of toxicity.

When should a nurse obtain a trough level for a client on divided doses of gentamicin?

Immediately before the next dose.

A client on gentamicin reports tinnitus and dizziness. What is the nurse's priority action?

Hold the medication and notify the provider to prevent permanent ototoxicity.

Which specific aminoglycoside is administered orally to suppress GI flora before colorectal surgery?

Neomycin

Aminoglycosides carry a high risk of nephrotoxicity. What urinary findings suggest acute tubular necrosis?

Proteinuria, casts in the urine, and elevated BUN/creatinine levels.

Why is it important to separate the administration of probiotics and antibiotics by at least 2 hours?

Antibiotics can kill the beneficial bacteria in the probiotic, rendering it ineffective.

A client with a history of a 'sulfa' allergy should avoid which classes of non-antibiotic medications due to potential cross-reactivity?

Thiazide diuretics, loop diuretics, and sulfonylurea-type oral hypoglycemics.

What is the priority nursing instruction to prevent crystalluria in a client taking trimethoprim-sulfamethoxazole?

Encourage an oral fluid intake of at least eight 8-oz glasses of water per day.

A client taking nitrofurantoin for a UTI reports a new onset of chills, cough, and chest pain. What is the nurse's priority?

Instruct the client to stop the medication immediately and report to the provider, as these indicate a hypersensitivity reaction.

What harmless side effect should the nurse warn a client about when starting nitrofurantoin?

The medication can turn urine a rust-yellow to brown color.

What is the 'Black Box Warning' associated with fluoroquinolones like ciprofloxacin?

Risk of Achilles tendon rupture.

A client on ciprofloxacin is also taking an antacid. How should the nurse schedule these medications?

Administer the antacid 6 hours before or 2 hours after ciprofloxacin to prevent decreased absorption.

What effect does phenazopyridine have on the color of a client's urine?

It changes the urine to an orange-red color.

What is the primary therapeutic use of phenazopyridine in a client with a UTI?

It acts as a local anesthetic on the urinary tract mucosa to relieve burning, pain, and urgency.

Why must a client with active tuberculosis take at least two different medications simultaneously?

To prevent the development of medication-resistant strains of M. tuberculosis.

A client starting isoniazid (INH) is prescribed pyridoxine ($Vitamin B_6$). What is the purpose of this supplement?

To prevent peripheral neuropathy (tingling/numbness) caused by INH.

Which food group should a client on isoniazid avoid to prevent hepatotoxicity and hypertensive crisis?

Foods high in tyramine (e.g., aged cheeses, cured meats).

A client on rifampin is distressed to find their tears and sweat have turned orange. What should the nurse tell them?

This is an expected, harmless effect of the medication and does not require discontinuation.

How many negative sputum cultures are typically required to confirm that a client is no longer infectious with tuberculosis?

Three negative cultures.

What interaction occurs between metronidazole and alcohol?

A disulfiram-like reaction (facial flushing, vomiting, tachycardia).

Which medication is the treatment of choice for systemic fungal infections but carries a high risk of nephrotoxicity?

Amphotericin B

How should a nurse prepare a client for a potential infusion reaction to amphotericin B?

Pretreat with diphenhydramine and acetaminophen.

Why is 1 liter of 0.9% sodium chloride administered on the day of an amphotericin B infusion?

To lessen the risk of kidney injury (nephrotoxicity).

Which laboratory value is most critical to monitor due to the risk of bone marrow suppression with ganciclovir?

Complete Blood Count (CBC), specifically WBC and platelet counts.

What instruction should the nurse give a client with herpes lesions regarding the application of topical acyclovir?

Wear rubber gloves to avoid spreading the virus to other areas of the body.

What is the primary goal of Highly Active Antiretroviral Therapy (HAART) in HIV treatment?

To reduce the viral load and increase CD4 counts to prevent opportunistic infections.

Which life-threatening adverse effect of zidovudine requires monitoring for hyperventilation and abdominal pain?

Lactic acidosis

A client on the NNRTI efavirenz reports having vivid nightmares. How should the nurse respond?

Inform the client that these CNS effects are common and typically decrease after the first few weeks of therapy.

What dietary instructions are provided to a client taking protease inhibitors like ritonavir to prevent bone loss?

Eat a diet high in calcium and vitamin D.

Which common herbal supplement is known to decrease the effectiveness of oral contraceptives and warfarin?

St. John’s wort

A client taking warfarin is considering taking garlic supplements. Why should the nurse advise against this?

Garlic has antiplatelet qualities that can increase the risk of bleeding when taken with anticoagulants.

What is the primary therapeutic use of feverfew?

To decrease the frequency and severity of migraine headaches.

A client with a shellfish allergy should use which herbal supplement with extreme caution?

Glucosamine (often extracted from crab or shrimp shells).

Why should a client stop taking feverfew two weeks before elective surgery?

To prevent an increased risk of bleeding during and after the procedure.

What is the purpose of black cohosh in postmenopausal clients?

It acts as an estrogen substitute to treat manifestations of menopause.

Which herbal supplement is claims to improve memory but is contraindicated in clients at risk for seizures?

Ginkgo biloba

What metabolic side effect should the nurse monitor for in a client taking protease inhibitors (PIs)?

Hyperlipidemia (elevated blood lipids) and hyperglycemia.

A client with HIV is prescribed enfuvirtide. By what route is this medication administered?

Subcutaneous injection

Which antiretroviral medication requires the nurse to assess breath sounds due to an increased risk of bacterial pneumonia?

Enfuvirtide

The herb valerian produces its sedative effect by increasing the amount of which neurotransmitter?

GABA

Why should a nurse question a client with tuberculosis or HIV about their use of echinacea?

Chronic use of echinacea (more than 6 months) can decrease the effectiveness of medications for TB or HIV.

A client with diabetes taking ginger root should be monitored for which blood glucose abnormality?

Hypoglycemia, as ginger can increase the effects of antidiabetic medications.

Which two FDA-approved medications are derived from chemical components of marijuana to treat nausea and anorexia?

Dronabinol and nabilone.

In the context of medical marijuana, how quickly do therapeutic effects typically occur following inhalation?

Within 10 minutes.

Why is acyclovir administered slowly over at least 1 hour?

To prevent nephrotoxicity by avoiding the crystallization of the drug in the renal tubules.

A client on rifampin is also taking oral contraceptives. What instruction is vital?

Use a non-hormonal form of contraception, as rifampin accelerates the metabolism of oral contraceptives.

What is the difference between 'Complementary' and 'Alternative' medicine?

Complementary medicine is used together with conventional medicine, while alternative medicine is used in place of it.

Which electrolyte imbalance is common in clients receiving amphotericin B?

Hypokalemia

A nurse is teaching a client about saw palmetto. What clinical test might this supplement interfere with?

Prostate-specific antigen (PSA) test.

What 'high-alert' complication is associated with the administration of IV ganciclovir solution to a nurse's own skin?

It is toxic; the nurse must wash the area well if contact occurs.

Which type of antibiotic action targets ribosomes that are never identical to mammalian ribosomes?

Inhibiting protein synthesis.

What laboratory test determines the 'Minimum Bactericidal Concentration' (MBC)?

Serial dilution

A client on gentamicin is also prescribed a loop diuretic. What is the combined risk?

Increased risk for ototoxicity.

Which medication is used specifically for the treatment of trichomoniasis?

Metronidazole

What is the primary contraindication for the use of phenazopyridine?

Acute kidney injury or chronic kidney disease.

A client reports 'metallic taste' after starting a medication for C. difficile. Which medication are they likely taking?

Metronidazole

A client on maraviroc (CCR5 antagonist) reports yellowing of the eyes. What is the priority nursing action?

Stop the medication and notify the provider, as this indicates hepatotoxicity.

How should a nurse instruct a client to take oral rifampin regarding food?

Take 1 hour before or 2 hours after meals with a full glass of water.

Which antiretroviral class interferes with the enzyme integrase to prevent HIV replication?

Integrase inhibitors (INSTIs) like raltegravir.

A client with HIV is taking raltegravir and reports suicidal thoughts. Is this an expected finding?

No; suicidal ideation is a complication of raltegravir and must be reported immediately.

What is the nurse's priority assessment before starting maraviroc therapy?

Baseline liver function tests, blood pressure, and CBC.

Why is it important for a client taking antiretroviral medications not to skip doses?

Missed doses promote medication resistance, leading to treatment failure.

A client on acyclovir should be encouraged to increase their intake of _____ to minimize nephrotoxicity.

Oral fluids

Which specific condition is a contraindication for the use of aloe orally?

Kidney disorders or history of cardiac disorders.

What is 'Integrative Health'?

A holistic approach that coordinates conventional treatments with complementary approaches.

Which herbal supplement can increase the hypoglycemic effects of insulin?

Black cohosh (also ginger and garlic).

A client is taking St. John's wort and an SSRI. They present with shivering, diarrhea, and muscle rigidity. What is the likely cause?

Serotonin syndrome

What is a 'Narrow-spectrum' antibiotic?

An antibiotic to which only a few types of bacteria are sensitive.

Which specific population is at the highest risk for antimicrobial toxicity due to slow medication metabolism and excretion?

Older adult clients

A client on ceftriaxone needs an IM injection. Where should the nurse administer it?

Deep into a large muscle mass, such as the ventrogluteal site.