Mycobacterial, Fungal, and Parasitic Infections

Question 1

Mycobacterium tuberculosis

Answer 1

• a slow-growing pathogen that necessitates long-term treatment
• long-term treatment increases risk for toxicity, poor client adherence, and development of medication-resistant strains
• treatment for tuberculosis requires use of at least 2 medications to which the pathogen is susceptible

Question 2

Metronidazole (Flagyl)

Answer 2

-medication of choice for parasitic infections

Question 3

Antimycrobacterial (antituberculosis)

Answer 3

• this medication is highly specific for mycobacteria. Isoniazid inhibits growth of mycobacteria by preventing synthesis of mycolic acid in the cell wall.
• select prototype medication = isoniazid (INH, Nydrazid)
• other medications = pyrazinamide (PZA), ethambutol (Myambutol) bacteriostatic only to M. tuberculosis, and rifapentine (Priftin)

Question 4

Antimycobacterial (antituberculosis): therapeutic uses

Answer 4

1) indicated for active and latent tuberculosis:
-Latent: isoniazid only (6-9 months), or isoniazid w/ rifapentine once weekly for 3 months.
(contraindicated in children < 2 yr, clients who have HPV, pregnant women, clients resistant to either med)
-Active: several antimycobacterial meds must be used in order to decrease med resistance. Multiple med therapy includes isoniazid, for minimum of 6 months.
-

Question 5

Antimycobacterial (antituberculosis):

adverse effects and nursing interventions/client education

Answer 5

1) peripheral neuropathy ( tingling, numbness, burning, and pain resulting from deficiency of pyridoxine, vitamin B6)–instruct clients to observe for manifestations and notify provider if occur; adminster 50-200 mg vitamin B6 daily
2) hepatotoxicity (anorexia, malaise, fatigue, nausea, and yellowish discoloration of skin and eyes)–instruct clients to observe for manifestations and notify provider; monitor liver function tests; instruct clients to avoid alcohol; med may need to be discontinued if liver function test results are elevated
3) hyperglycemia and decreased glucose control in clients who have diabetes mellitus–monitor blood glucose; clients who have diabetes mellitus may need additional antidiabetic med

Question 6

Antimycobacterial (antituberculosis):

contraindications/precautions

Answer 6

1) isoniazid is contraindicated for clients who have liver disease
2) use cautiously in older clients, and those who have diabetes mellitus or alcohol use disorder

Question 7

Antimycobacterial (antituberculosis): interactions

Answer 7

1) isoniazid inhibits metabolism of phenytoin, leading to buildup of medication and toxicity. Ataxia and incoordination may indicate toxicity–monitor client’s level of phenytoin. Dosage of phenytoin may need to be adjusted based on phenytoin levels
2) concurrent use of alcohol, rifampin, and pyrazinamide increases risk of hepatotoxicity–instruct clients to avoid alcohol; monitor liver function

Question 8

Antimycobacterial (antituberculosis):

nursing administration

Answer 8

1) usually administered orally. When given IM, ensure solution is free of crystals and inject deeply into large muscle
2) for active TB, direct observation therapy (DOT) is done to ensure adherence
3) advise clients to take isoniazid 1 hr before meals or 2 hr after. If gastric discomfort occurs, client can take it w/ meals
4) instruct client to complete prescribed course

Question 9

Antimycobacterial (antituberculosis) [rifampin (Rifadin)]

Answer 9

• rifampin is bactericidal as a result of protein synthesis

- select prototype medication = rifampin (Rifadin)

Question 10

Rifampin (Rifadin): therapeutic uses

Answer 10

1) broad-spectrum antibiotic effective for gram-positive and gram-negative bacteria, M. tuberculosis, and M. leprae
2) given in combination w/ at least one other antituberculosis med to help prevent antibiotic resistance

Question 11

Rifampin (Rifadin):

adverse effects and nursing interventions/client education

Answer 11

1) discoloration of body fluids–instruct clients of expected orange color of urine, saliva, sweat, and tears
2) hepatotoxicity (jaundice, anorexia, and fatigue)–monitor liver function; inform clients regarding manifestations of anorexia, fatigue, and malaise and instruct them to notify provider if they occur; instruct clients to avoid alcohol
3) mild GI discomfort associated w/ anorexia, nausea, and abdominal discomfort–mild and usually does not require intervention

Question 12

Rifampin (Rifadin): contraindications/precautions

Answer 12

-use cautiously in clients who have liver dysfunction

Question 13

Rifampin (Rifadin): interactions

Answer 13

1) rifampin accelerates metabolism of warfarin (Coumadin), oral contraceptives, protease inhibitors, and NNRTIs (meds for HIV), resulting in diminished effectiveness–increased dosages of HIV meds may be necessary; monitor PT and INR; clients may need to use alternative methods of birth control
2) concurrent use w/ isoniazid and pyrazinamide increases risk of hepatotoxicity–instruct clients to avoid alcohol; monitor liver function

Question 14

Rifampin (Rifadin): nursing administration

Answer 14

1) administer orally or by IV route

2) administer oral rifampin 1 hr before or 2 hrs after meals. Absorption is decreased if given w/ food

Question 15

Antiprotozoals

Answer 15

• metronidazole is a broad-spectrum antimicrobial w/ bactericidal activity against anaerobic micro-organisms
• select prototype medication = metronidazole (Flagyl)

Question 16

Antiprotozoals: therapeutic uses

Answer 16

1) treatment of protozoal infections (intestinal amebiasis, giardiasis, trichomoniasis) and obligate anaerobic bacteria (Bacteroides fragilis, antibiotic-induced Clostridium difficule, Gardnerella vaginalis)
2) prophylaxis for clients who will have surgical procedures and are high-risk for anaerobic infection (vaginal, abdominal, colorectal surgery)
3) treatment of H. pylori in combination w/ tetracycline and bismuth salicylate in clients who have peptic ulcer

Question 17

Antiprotozoals:

adverse effects and nursing interventions/client education

Answer 17

1) GI discomfort (nausea, vomiting, dry mouth, metallic taste)–advise clients to observe for effects and notify provider
2) darkening of urine–advise clients that this is a harmless effect of metronidazole
3) CNS symptoms (numbness of extremities, ataxia, and seizures)–advise clients to notify provider; stop metronidazole

Question 18

Antiprotozoals: contraindications/precautions

Answer 18

1) contraindicated in active CNS disorders, blood dyscrasias, and during lactation
2) contraindicated during 1st trimester of pregnancy in clients who have trichomoniasis
3) use cautiously in clients who have renal, cardiac, or seizure disorders and in older adults

Question 19

Antiprotozoals: interactions

Answer 19

1) alcohol causes a disulfiram-like reaction–advise clients to avoid alcohol
2) metronidazole inhibits inactivation of warfarin–monitor prothrombin time and INR and adjust warfarin dose accordingly

Question 20

Antifungals

Answer 20

• amphotericin B is an antifungal agent that acts on fungal cell membranes to cause cell death. Depending on concentration, these agents can be fungistatic (slows growth on the fungus) or fungicidal (destroys the fungus)
• select prototype medications = amphotericin B (Fungizone), a polyene antibiotic for systemic mycoses and ketoconazole (Nizoral), and azole for treating both superficial and systemic mycoses
• other medications =
• flucytosine (Ancobon)
• nystatin (Mycostatin)
• miconazole (Monistat)
• clotrimazole (Lotrimin)
• terbinafine (Lamisil)
• fluconazole (Diflucan)
• griseofulvin (Grifulvin)

Question 21

Antifungals: therapeutic uses

Answer 21

• treatment of choice for systemic fungal infection (Candidiasis, Aspergillosis, Cryptococcosis, Mucormycosis) and nonopportunistic mycoses, (Blastomycosis, Histoplasmosis, Coccidioidomycosis)
• some antifungals treat superficial fungal infections: dermatophytic infections (tinea pedis [ringworm of the foot], tinea cruris [ringworm of the groin]); candida infections of the skin and mucous membranes; and fungal infections of the nails (Onychomycosis)

Question 22

Antifungals:

adverse effects and nursing interventions/client education

Answer 22

1) infusion reactions (fever, chills, rigors, and headache) 1-3 hr after initiation–a test dose of 1 mg amphotericin B, infused slowly IV, may be prescribed to assess client reaction; pretreat w/ diphenhydramine (Benadryl) and acetaminophen; meperidine (Demerol), dantrolene, or hydrocortisone may be given for rigors
2) thrombophlebitis–observe infusion sites for signs of erythema, swelling, and pain; rotate injection sites; administer in a large vein and administer heparin before infusing amphotericin B
3) nephrotoxicity–obtain baseline kidney function (BUN and creatinine) and do weekly kidney function tests; monitor I&O; infuse 1 L saline on day of amphotericin B infusion
4) hypokalemia–monitor electrolyte levels, especially potassium; administer potassium supplements accordingly
5) bone marrow suppression–obtain baseline CBC and hematocrit, and monitor weekly

Question 23

Ketoconazole:

adverse effects and nursing interventions/client education

Answer 23

1) hepatotoxicity (anorexia, nausea, vomiting, jaundice, dark urine, and clay-colored stools)–obtain baseline liver function studies, and monitor liver function monthly; if manifestations occur, notify provider and discontinue medication
2) effects on sex hormones: in males, gynecomastia (enlargement of breast), decreased libido, erectile dysfunction. in females: irregular menstrual flow–advise clients to observe for these effects and notify provider

Question 24

Antifungals: contraindications/precautions

Answer 24

-antifungals are contraindicated in clients who have renal dysfunction because of the risk for nephrotoxicity

Question 25

Antifungals: interactions

Answer 25

1) aminoglycosides (gentamicin, streptomycin, cyclosporine) have additive nephrotoxic risk when used concurrently w/ antifungal meds–avoid use of these antimicrobials when clients are taking amphotericin B due to additive nephrotoxicity risk
2) -antifungal effects of flycytosine are potentiated w/ concurrent use of amphotericin B AND
- fluconazole is pregnancy risk category C in low doses and category D in high dose; contraindicated during lactation–potentiating the effects of flucytosione allows for a reduction in amphotericin B dosages.
3) azole antibiotics increase levels of multiple medciations, incluiding digoxin, warfarin, and sulfonylurea antidiabetic medications–if concurrent administration is necessary, carefully monitor for toxicity

Question 26

Antifungals: nursing administration

Answer 26

1) amphotericin B is highly toxic and should be reserved for severe life-threatening fungal infections
2) amphotericin B should be infused slowly over 2-4 hr by IV route, because oral preparation is poorly absorbed in the GI tract. Observe solutions for precipitation and discard if precipitates are present. Renal damage can be lessened w/ administration of 1 L saline solution on day of amphotericin B infusion
3) instruct clients to complete course, even if symptoms disappear
4) antifungals for topical use to treat superficial vulvovaginal candidiasis may be applied as vaginal suppository or cream