Introduction

Antifungal medications represent the group of drugs that are designed to treat fungal infections. A fungal infection occurs when harmful fungi invade and grow on or inside the body. Fungi, including moulds and yeasts, can multiply and cause a range of infections, from common skin issues to more serious health concerns. Depending on the type of fungus, infections can affect the skin, nails or hair. Antifungal medicines work by attacking different parts of fungal cells, either stopping their growth or getting rid of them entirely.¹

Fungal infеctions posе a significant thrеat to patiеnts with compromisеd immunе systеms, such as thosе undеrgoing chеmothеrapy or organ transplantation.² Antifungal mеdications arе еssеntial in managing common conditions likе athlеtе's foot, ringworm, and yеast infеctions. Thеy offеr an еffеctivе mеans of trеatmеnt, allеviating symptoms and prеvеnting thе sprеad of infеctions. Thеy play a crucial role in еnhancing thе ovеrall wеll-bеing of individuals, safеguarding against thе divеrsе and somеtimеs lifе-thrеatеning consеquеncеs of fungal infеctions. 

In this article, we will delve into the types of antifungal medications, how they work against infections, the infections they treat, their side effects, and resistance.

Risk factors for fungal infections

People with a weak immune system (opportunistic infections) have an elevated risk of developing fungal infections. For people who carry these infections, the consequences can be life-threatening–

• HIV/AIDS
• Organ transplant 
• Cancer 
• Stem cell (Bone marrow transplant)
• Autoimmune diseases such as lupus

Symptoms of fungal infections

Fungal infections can affect various parts of the body, and symptoms may vary depending on the type of fungus and the area of the body involved. Here are some common symptoms associated with fungal infections–

Fungal infection in superficial or subcutaneous area

• Itching, soreness, redness or rash in the affected area
• Discolored, thick or cracked nails
• Pain while eating
• Loss of taste 
• White patches in the mouth or throat
• Painless lump under your skin

Fungal infection in the lungs

• Cough
• Fatigue 
• Fever
• Shortness of breath
• Muscle ache
• Joint pain
• Headache
• Night sweats

Fungal infection in and around the brain

• Headache
• Fever
• Neck pain
• Nausea
• Sensitivity to light
• Confusion

Fungal infection in the eyes

• Pain
• Redness
• Blurred vision
• Sensitivity to light

Fungal infection in the intestinal tract

• Abdominal pain
• Nausea
• Vomiting

Fungal infection in sinuses

• Fever
• Nasal congestion
• Headache
• One-sided facial swelling
• Face pain

Infections treated by antifungal medications

Antifungal medications are used to treat a variety of fungal infections, which can affect different parts of the body. Here is a list of common fungal infections that are typically treated with antifungal medications–

Athlete's foot (tinea pedis)

Athlete's foot is a fungal infection causing itching, peeling, and redness, typically affecting the skin between the toes.

Ringworm (tinea corporis)

Ringworm is a contagious fungal infection causing red, itchy, and ring-shaped rashes on the skin.

Jock itch (tinea cruris)

Jock itch is a fungal infection characterised by redness, itching, and a rash in the groin area.

Vulvovaginal candidiasis

Vulvovaginal candidiasis is a fungal infection characterised by itching, burning, and abnormal discharge in the vaginal area, caused by an overgrowth of Candida yeast.

Oral thrush (oropharyngeal candidiasis)

Oral thrush is a fungal infection in the mouth characterised by the presence of white, creamy lesions on the tongue, inner cheeks, and throat caused by Candida overgrowth.

Esophageal candidiasis

Esophageal candidiasis is a fungal infection of the esophagus, often seen in immunocompromised individuals, causing symptoms such as difficulty swallowing.

Invasive candidiasis

Invasive candidiasis is a serious bloodstream infection caused by Candida yeast, leading to systemic complications and presenting symptoms ranging from fever and chills to organ dysfunction.

Seborrheic dermatitis

Seborrheic dermatitis is a chronic skin condition causing redness, inflammation, and flaky scales, commonly affecting areas rich in oil glands, such as the scalp and face.

Onychomycosis

Onychomycosis is a fungal infection of the nails characterized by discolouration, thickening, and brittleness, often affecting the toenails and fingernails.

Paronychia

Paronychia is an infection of the skin around the nails, leading to redness, swelling, and discomfort.

Histoplasmosis

Histoplasmosis is a respiratory infection caused by inhaling spores of the fungus Histoplasma, often presenting as a flu-like illness and occasionally progressing to severe lung disease.

Aspergillosis

Aspergillosis is a fungal infection caused by the inhalation of Aspergillus spores, which can affect the respiratory system and, in severe cases, lead to systemic complications in immunocompromised individuals.

Cryptococcosis

Cryptococcosis is a fungal infection caused by inhaling Cryptococcus spores, typically affecting the lungs and, in severe cases, spreading to the central nervous system.

Pneumocystis pneumonia (PCP)

Pneumocystis pneumonia is a fungal lung infection affecting individuals with weakened immune systems, such as those with HIV/AIDS.

Fungal meningitis

Fungal meningitis is an infection of the membranes covering the brain and spinal cord, caused by fungal pathogens, and can lead to symptoms such as severe headaches, neck stiffness, and fever.

Fungal sinusitis

Fungal sinusitis is an inflammation and infection of the sinuses caused by fungi, often presenting with symptoms such as nasal congestion, facial pain, and sinus headaches.

Fungal keratitis

Fungal keratitis is a fungal infection of the cornea, the clear front surface of the eye, typically resulting from trauma or contact lens use and characterized by redness, pain, and vision disturbances.

Fungal endophthalmitis

Fungal endophthalmitis is a serious infection inside the eye, often leading to severe inflammation and potential vision loss.

Class of antifungal drugs

Antifungal mеdications arе dеsignеd to trеat fungal infеctions by targеting specific aspects of fungal cеll structurе or function. Thе choicе of antifungal mеdication dеpеnds on thе typе of fungal infеction, its sеvеrity, and thе spеcific characteristics of thе patiеnt.¹ 

Hеrе arе somе of thе main classеs of antifungal drugs:

Azoles 

These drugs (e.g. ketoconazole, miconazole) interfere with the walls of the fungal cells, making them weak and causing the cells to die.³ 

Echinocandins 

These drugs (e.g. caspofungin) stop the fungus from building strong walls, which are like the armour of the fungal cells. Without this wall, the structure of the fungus becomes compromised and it dies.³

Flucytosine

These drugs interfere with the ability of the fungus to make important building blocks (RNA and DNA), disrupting its growth and causing it to die.¹

Griseofulvin

These drugs interfere with the ability of the fungus to divide and make new cells by interfering with tiny structures called microtubules inside the cell.¹

Polyenes

These drugs (e.g. amphotericin B, natamycin, and nystatin) breach the outer layer of fungus cells, causing cell components to leak out and leading to the death of the cells.³

Allylamines

These drugs (e.g. terbinafine) target the fungal cells by disrupting a key component involved in building their cell walls. By interfering with this process, allylamines weaken the fungal cell structure, ultimately leading to the death of cells.¹

Types of antifungal medications

Antifungal medicines come in various forms, each designed to target different types of fungal infections and specific areas of the body.

Topical antifungal medications 

These medications are available in the form of creams, gels, ointments, or sprays and are directly applied to the affected skin or area. Examples include clotrimazole, ketoconazole, miconazole, terbinafine, and amorolfine.⁴

Oral antifungal medications 

These medications are available in the form of capsules, tablets, or liquid, taken by mouth with water. They are commonly used for systemic fungal infections affecting internal organs or widespread areas of the body. Examples include miconazole, nystatin, itraconazole, fluconazole and terbinafine.⁴

Intravenous antifungal medications 

These medications are delivered through injections directly into the bloodstream. This method is reserved for severe or life-threatening fungal infections, especially when oral medications are ineffective. Examples include amphotericin, flucytosine, itraconazole, voriconazole, anidulafungin, caspofungin, and micafungin.⁴

Pessaries 

These are small, soft tablets inserted into the vagina. They are used for treating vaginal yeast infections, releasing the antifungal medication directly to the affected area. Example include lotrimazole, econazole and miconazole.⁴

Side effects of antifungal medications

The side effects of antifungal medications include:

• Itching or burning
• Redness
• Abdominal pain
• Diarrhoea
• Rash
• Swelling in the face, neck or tongue
• Peeling or blistering skin
• Liver damage (very rarely) – loss of appetite, vomiting, nausea, jaundice

Who should not take antifungal medications?

When using antifungal medicines, there are several important considerations to keep in mind to ensure their effectiveness and minimise potential risks. Here are some key points to consider–

• If you have any pre-existing conditions or allergies that might impact the efficacy of your fungal infection treatment.
• Potential side effects associated with antifungal medications.
• Possible interactions between the antifungal medicine and any other medications you are currently using.
• If your antifungal medicine is suitable to take during pregnancy or while breastfeeding – many are not suitable. 

Antifungal drug resistance

Antifungal drug resistance refers to the ability of fungi to survive and grow despite the presence of antifungal medications designed to inhibit or kill them. In other words, some fungi have developed mechanisms that allow them to resist the effects of certain antifungal drugs, making the treatment less effective or even ineffective.⁵ Here are some key factors contributing to antifungal drug resistance–

• Improper use
• Incomplete treatment
• Natural or transmitted resistance
• Environmental factors
• Genetic mutations
• Cross-resistance
• Biofilm formation⁵

Summary

Antifungal mеdications rеprеsеnt thе group of drugs that arе dеsignеd to trеat fungal infеctions. Thеsе drugs targеt fungal cеlls, inhibiting thеir growth or dеstroying thеm еntirеly. Commonly used antifungals include azolеs, polyеnеs, and еchinocandins. Azolеs intеrfеrе with fungal cеll mеmbranе formation, polyеnеs disrupt mеmbranе intеgrity, and еchinocandins inhibit cеll wall synthеsis. Antifungals arе crucial in trеating a variety of infеctions, such as athlеtе's foot, ringworm, and systеmic fungal disеasеs. Howеvеr, thеir usе rеquirеs carеful considеration of potеntial sidе еffеcts and intеractions, еmphasizing thе importancе of mеdical supеrvision and propеr diagnosis for еffеctivе trеatmеnt.