Fungal infections, also known as mycoses, have increasingly become a significant concern nowadays. From superficial skin infections to life-threatening systemic diseases, fungi are unique organisms that require specialized therapeutic approaches.
Types of Fungal Infections
Fungal infections are often chronic and may involve:
- Cutaneous infections: Limited to the skin (extending into the epidermis).
- Subcutaneous infections: Affecting deeper tissues.
- Systemic infections: Involving internal organs.
Fungal Structure and Growth
Fungi are eukaryotic organisms, having a cell wall composed largely of chitin (unlike bacteria, which have peptidoglycan). Moreover, it also has a cell membrane that contains ergosterol (instead of cholesterol found in mammalian membranes). In terms of growth, fungi are slow growers compared to bacteria.
Mechanism of Antifungal Drugs
Antifungal drugs are the ones that kill fungi and help resolve a fungal infection. Antifungal drugs exert their therapeutic effects by targeting the unique structural components of fungi, which are chitin and ergosterol. They serve as a useful drug target because the human bodies lack them, hence a good target with fewer adverse effects. Furthermore, some drugs also work by interfering with fungal cell division; however, options are limited for that.
Resistance Patterns
Fungal infections are generally resistant to antibacterial antibiotics; conversely, bacteria are resistant to antifungal agents.
Epidemiology of Mycoses
The incidence of mycoses, such as candidemia, is less frequent than bacterial or viral infections. However, incidence has increased significantly in recent decades. The reason for the increased incidence of fungal infection is a rising number of patients with chronic immunosuppression due to:
- Organ transplantation
- Cancer chemotherapy
- Human immunodeficiency virus (HIV) infection
Global Burden of Fungal Diseases
Candida bloodstream infections and invasive candidiasis affect approximately 1.565 million people annually, with a mortality rate of about 63.6%, resulting in roughly 995,000 deaths each year.
An estimated 6.55 million people worldwide develop life-threatening fungal infections annually, causing about 3.75 million deaths.
Advances in Antifungal Therapy
With time and the increased burden of fungal infections, new developments have taken place in antifungal medications, such as the introduction of the echinocandins (a new class of antifungals) and safer and more bioavailable formulations of itraconazole and amphotericin B.
Clinical Considerations
Antifungal agents differ significantly in their activity spectrum, toxicity profiles, and drug interaction potential. These differences are clinically important because they enable clinicians to tailor therapy to the specific needs of each patient. Selecting the most appropriate antifungal requires careful consideration of the infecting organisms susceptibility, the site and severity of infection, potential adverse effects, and the likelihood of interactions with other medications the patient is receiving.
General Use of Antifungal Drugs
The general use of antifungal drugs is focused on treating fungal infections of varying severity. Topical and vaginal preparations are commonly used for infections limited to the skin or mucous membranes, while oral or parenteral therapies are necessary for deep-seated or systemic infections. Some antifungal agents, such as lipid-based formulations of amphotericin B, are specially designed with lipid encapsulation to help reduce nephrotoxicity. These drugs work by exerting fungicidal or fungistatic effects, either disrupting the permeability of the fungal cell membrane or interfering with protein synthesis within the fungal cell. It is important to note that antifungal medications are contraindicated in patients with previous hypersensitivity to the drug or any of its components.
Precautions with Antifungal Drug Use
With the use of antifungal agents, some precautions should be kept in mind, such as:
- Systemic antifungals may impair bone marrow function; therefore, use cautiously in patients with depressed bone marrow reserve.
- Amphotericin B: Commonly causes renal impairment.
- Fluconazole:
- Requires dosage adjustment in renal impairment.
- May cause more severe adverse reactions in HIV-positive patients.
- Voriconazole IV formulation: Should be avoided in patients with renal impairment.
Nursing Implications of Antifungal Drugs
As a nurse, it is crucial to know the nursing implications when administering antifungal drugs to the patient. They include:
Assessment
- Assess for signs and symptoms of infection before and during therapy.
- Inspect the involved skin and mucous membranes.
- Monitor for increased irritationmay require discontinuation.
Potential Nursing Diagnoses
- Risk for Infection (related to fungal disease).
- Impaired Skin Integrity (related to lesions or irritation).
- Deficient Knowledge (related to disease process and medication regimen).
Implementation
- Available in multiple dosage formsconsult references for administration guidance.
- Topical Application:
- Confirm the appropriate cleansing technique with the prescribing provider.
- Wear gloves during application.
- Do not use occlusive dressings unless directed by a health care professional.
Patient/Family Teaching
- Instruct the patient on proper use of the medication form (e.g., topical, oral, IV).
- Emphasize the importance of continuing medication as directed for the full course, even if feeling better.
- Advise the patient to report any increased skin irritation or lack of therapeutic response to the health care professional.
Common Antifungal Drugs, Their Indications, and Side Effects
Below is a table summarizing some of the most commonly used antifungal medications, their primary clinical indications, and notable side effects. This overview can help guide the appropriate selection and monitoring of antifungal therapy in various patient populations.
| Drug Name | Indications | Side Effects |
| Caspofungin (Cancidas) | - Candidemia
- Invasive aspergillosis
- Empiric therapy for presumed fungal infections in febrile neutropenic patients | - Headache
- Nausea, vomiting
- Diarrhea
- Increased hepatic function tests |
| Fluconazole (Diflucan) | - Vaginal candidiasis
- Oropharyngeal and esophageal candidiasis
- Cryptococcal meningitis
- Prophylaxis in bone marrow transplant patients | - Nausea, vomiting, abdominal pain, diarrhea
- Dysgeusia (altered taste)
- Increased hepatic function tests
- Liver necrosis, hepatitis, cholestasis
- Headache
- Rash, pruritus
- Eosinophilia
- Alopecia |
| Isavuconazonium (Cresemba) | - Invasive aspergillosis
- Invasive mucormycosis | - Nausea, vomiting, diarrhea
- Increased hepatic enzymes
- Hypokalemia
- Constipation
- Dyspnea, cough
- Peripheral edema
- Back pain |
| Itraconazole (Sporanox) | - Blastomycosis
- Histoplasmosis
- Aspergillosis
- Onychomycosis
- Empiric therapy in febrile neutropenic patients
- Oropharyngeal and esophageal candidiasis | - Congestive heart failure
- Peripheral edema
- Nausea, vomiting, abdominal pain, diarrhea
- Increased hepatic function tests
- Liver necrosis, hepatitis, cholestasis
- Headache
- Rash, pruritus
- Eosinophilia |
| Micafungin (Mycamine) | - Esophageal candidiasis
- Candida infections
- Prophylaxis in hematopoietic stem cell transplant patients | - Fever, chills
- Hypokalemia, hypomagnesemia, hypocalcemia
- Myelosuppression, thrombocytopenia
- Nausea, vomiting, abdominal pain, diarrhea
- Increased liver function tests
- Dizziness, headache
- Rash, pruritus
- Pain or inflammation at injection site |
| Posaconazole (Noxafil) | - Prevention of invasive aspergillus and candida infections in immunocompromised patients ≥ 13 years
- Oropharyngeal candidiasis | - Fever, headache
- Nausea, vomiting, diarrhea, abdominal pain
- Hypokalemia
- Cough, dyspnea |
| Voriconazole (Vfend) | - Invasive aspergillosis
- Candidemia
- Esophageal candidiasis
- Serious fungal infections | - Visual disturbances
- Nausea, vomiting, abdominal pain, diarrhea
- Increased hepatic function tests
- Liver necrosis, hepatitis, cholestasis
- Headache
- Rash, pruritus
- Eosinophilia |
Conclusion
Fungal infections can range from mild skin problems to serious illnesses that affect the whole body. Because fungi are different from bacteria, they need special medicines that target their unique structures. Over time, new antifungal drugs have made treatment safer and more effective. However, it is still important to choose the right medicine carefully, watch for side effects, and be aware of possible drug interactions. With the right approach, most fungal infections can be managed successfully.
About the Author:
Mariya Rizwan is an experienced pharmacist who has been working as a medical writer for four years. Her passion lies in crafting articles on topics ranging from Pharmacology, General Medicine, Pathology, to Pharmacognosy.
Mariyais an independent contributor to CEUfast's Nursing Blog Program. Please note that the views, thoughts, and opinions expressed in this blog post are solely those of the independent contributor and do not necessarily represent those of CEUfast. This blog post is not medical advice. Always consult with your personal healthcare provider for any health-related questions or concerns.
If you want to learn more about CEUfast's Nursing Blog Program or would like to submit a blog post for consideration, please visit https://ceufast.com/blog/submissions.
