1. Introduction to Clinical Pharmacology Chapter 12 Antifungal and Antiparasitic Drugs

2. Antifungal Drugs: Actions and Uses
Fungicidal OR fungistatic: Action is related to their concentration in body tissues
Used prophylactically to prevent fungal infection in immunocompromised patients
Used to treat superficial and deep fungal infections; systemic infections; superficial infections of nail beds and oral, anal, and vaginal areas

3. Helminthic and Protozoal Infections and Amebiasis
Helminthic infections: Invasion of body by parasitic worms
Anthelmintic drugs kill the parasites
Protozoal infections: Single-cell parasites
Antiprotozoal drugs work to inhibit DNA synthesis, effectively killing the organism
• Amebiasis is a parasitic gastrointestinal disorder

4. Antifungal Drugs: Adverse Reactions
Topical administration: Integumentary reactions
Irritation and burning sensation; redness, stinging; abdominal pain (vaginal preparations)
Systemic administration
Headache; rash; nausea; vomiting; diarrhea; anorexia and malaise; abdominal, joint, or muscle pain

5. Antifungal Drugs: Contraindications, Precautions, and Interactions
Contraindicated in patients with a history of allergies to the drug; during pregnancy and lactation
Contraindications for antifungal drugs: Griseofulvin; voriconazole; itraconazole
Used cautiously in patients with renal dysfunction and/or hepatic impairment
Interactions possible depending on the individual drugs, and many interactions can occur

6. Nursing Process: Assessment
Preadministration assessment:
Assess for signs of the infection before giving the first dose; take and record vital signs
Inspect superficial fungal infections of the skin or skin structures and record
Ask about pain and presence of white plaques or sore areas of the oral or perineal areas and any vaginal discharge

7. Nursing Process: Assessment (cont.)
Ongoing assessment:
Carefully observe the patient every 2 to 4 hours for adverse drug reactions
If administered topically, instruct the patient to look for signs of improvement and adverse reactions both minor and severe

8. Nursing Process: Nursing Diagnosis
Impaired Comfort related to IV administration of amphotericin B
Risk for Ineffective Tissue Perfusion: Renal related to adverse reactions of antifungal drugs

9. Nursing Process: Planning
The expected outcome depends on the reason for administering the antifungal drug but includes an optimal response to therapy:
Patient relates to the management of adverse reactions and has an understanding of and compliance with the prescribed treatment regimen

10. Nursing Process: Implementation
Promoting an optimal response therapy:
Amphotericin B: Protect IV solution from exposure to light; administer immediately after the drug is reconstituted; renal damage is the most serious adverse reaction to the use of amphotericin B— hence, serum creatinine levels and BUN levels are checked frequently

11. Nursing Process: Implementation (cont.)
Promoting an optimal response therapy (cont.):
Topical antifungal infection preparations: Inspect the area at the time of each topical application; if administered vaginally, question the patient regarding any discomfort or other sensations experienced; evaluate and chart the patient’s response to therapy daily

12. Nursing Process: Implementation (cont.)
Monitoring and managing patient needs:
Impaired comfort: Medication administration
Use precautions when administering amphotericin B intravenously; inform before the drug is given that the side effects can be uncomfortable; provide warm blankets; reassure that the medications administered before the antifungal are to help ease the reaction

13. Nursing Process: Implementation (cont.)
Monitoring and managing patient needs (cont.):
Risk for ineffective tissue perfusion: Renal
Carefully monitor fluid intake and output, serum creatinine levels, and BUN levels
Gerontologic alert: Fluconazole

14. Nursing Process: Implementation (cont.)
Educating the patient and family:
For topical antifungal drugs include the importance of cleanliness and using the correct ointment amount in the prescribed frequency in the teaching plan
For ringworm infections advise keeping towels and facecloths used for bathing separate from those of other family members

15. Nursing Process: Implementation (cont.)
Educating the patient and family (cont.):
Teach drug-specific points for the following drugs
Flucytosine; griseofulvin; ketoconazole; itraconazole; miconazole

16. Nursing Process: Evaluation
The therapeutic effect is achieved; signs and symptoms of infection improve; optimal skin integrity is maintained
Adverse reactions are identified, reported, and managed
Patient and family demonstrate understanding of the drug regimen
Patient verbalizes the importance of complying with the prescribed therapeutic regimen

17. Antiparasitic Drugs
Anthelmintic drugs: Used against invasion of parasitic worms (helminthiasis)
Antiprotozoal drugs: Used against invasion of single-celled parasites

18. Anthelmintic Drugs: Actions and Uses
Albendazole: Interferes with synthesis, resulting in death of larva; used to treat larval forms of pork tapeworm and liver, lung, and peritoneum disease caused by dog tapeworm
Mebendazole: Blocks glucose uptake by helminth; used to treat whipworm, pinworm, roundworm, American hookworm, and common hookworm
Pyrantel: Ability to paralyze helminth; used to treat roundworm and pinworm
Thiabendazole: Interrupts the life cycle of the helminth; used to treat threadworm

19. Anthelmintic Drugs: Adverse Reactions
Generalized adverse reactions:
Drowsiness, dizziness, nausea, vomiting, abdominal pain and cramps, diarrhea
Serious adverse effects:
Rash

20. Anthelmintic Drugs: Contraindications and Precautions
Contraindicated in patients:
With a history of hypersensitivity; during pregnancy
Used cautiously in patients:
With hepatic or renal impairment; during lactation; with malnutrition or anemia

21. Anthelmintic Drugs: Interactions
Interactant drug
Effect of interaction
Dexamethasone
Increased effectiveness of
albendazole
Cimetidine
Interferes with elimination of albendazole
Hydantoins and
carbamazepine
Lower levels of
mebendazole
Xanthine derivatives
Increased serum level, possible toxic effects of the xanthines

22. Antiprotozoal Drugs: Actions and Uses
Interfere with life cycle of the plasmodium
Prevent development of plasmodium
Prevent the mosquito from ingesting the plasmodium
Used for the treatment of:
Malaria

23. Antiprotozoal Drugs: Adverse Reactions
Gastrointestinal reactions:
Vomiting; anorexia; abdominal cramping; diarrhea; nausea
Other body system reactions:
Headache; dizziness; visual disturbances; hypotension; photosensitivity; cinchonism

24. Antiprotozoal Drugs: Contraindications and Precautions
Contraindicated in patients:
With known hypersensitivity; during pregnancy
Used cautiously:
With children; lactating patients; patients with hepatic or renal disease or bone marrow depression
Quinine not prescribed for:
Patients with myasthenia gravis

25. Antiprotozoal Drugs: Interactions
Interactant drug
Effect of interaction
Antacids, iron
Decreased absorption of the antimalarial
Digoxin
Increased risk of digoxin toxicity
Barbiturates, phenytoin, and carbamazepine
Decreased effectiveness of doxycycline
Warfarin
Increased risk of bleeding

26. Antiparasitic Drugs: Nursing Process: Assessment
Preadministration assessment:
Diagnosis of helminth infection: Examination of stool; weigh patient to determine drug dosage
Ongoing assessment:
Save and transport all stools passed after intake of drug to laboratory
Acutely ill: Monitor vital signs; record fluid intake/output every 4 hours
Observe patient for adverse reactions

27. Antiparasitic Drugs: Nursing Process: Nursing Diagnosis
Diarrhea related to parasitic invasion of body
Risk for Deficient Fluid Volume related to parasitic invasion of body
Imbalanced Nutrition: Less Than Body Requirements—adverse reaction to drug therapy
Risk for Impaired Respiratory Function— adverse reaction to drug therapy

28. Antiparasitic Drugs: Nursing Process: Planning
Depends on the patient and the type of helminth infection
Outcome: Reduction of anxiety, optimal response to therapy, management of adverse reactions, understanding of and compliance with prescribed therapeutic regimen

29. Antiparasitic Drugs: Nursing Process: Implementation
Promoting optimal response to therapy:
Patient and family: Explain treatment and future preventive measure; discuss concerns and questions
Based on the hospital policy, linen precaution necessary

30. Antiparasitic Drugs: Nursing Process: Implementation (cont.)
Monitoring and managing patient needs:
Diarrhea and risk of fluid body volume deficit: Monitor fluid intake and output; IV fluid and electrolyte replacement may be necessary
Risk for imbalanced nutrition: Gastrointestinal upset causing nausea, vomiting, abdominal pain, and diarrhea; consider patient’s food preference and encourage intake of nutritious balanced meal
Risk for impaired respiratory function: With inhaled treatments of pentamidine, bronchodilator may be prescribed; instruct patient and family on use

31. Antiparasitic Drugs: Nursing Process: Implementation (cont.)
Educating patients and family members:
Instruction about taking the drugs as well as the household precautions to be followed until helminth is eliminated
Prepare the education plan to be followed

32. Antiparasitic Drugs: Nursing Process: Evaluation
Therapeutic effect achieved; adverse reactions identified, reported, and successfully managed; stool specimen negative for parasites; patient verbalizes an understanding of the therapeutic regimen modalities and the importance of continued follow-up testing, and complying with the prescribed regimen and preventive measures

33. Question Is the following question true or false?
Itraconazole is taken on an empty stomach. Therapy continues for at least 6 months until the infection is controlled.

34. Answer
False
Itraconazole is taken with food. Therapy continues for at least 3 months until the infection is controlled.

35. Question Is the following question true or false?
A fungus is a single-celled plant that can cause yeast-like infections.

36. Answer
True
A fungus is a single-celled plant that can cause yeast-like infections. These are called fungal or mycotic infections. Antifungal drugs slow or destroy fungi.

37. Question Is the following statement true or false?
Superficial fungal infections to the skin, nails, and genital area are bothersome and are treated with parenteral medications.

38. Answer
False
Superficial fungal infections to the skin, nails, and genital area are bothersome and are treated topically or by oral preparations. Systemic infections happen when the fungi gain entry into the body; these are serious infections, especially for those immunocompromised.