10. BIO250 Lesson 10: Antifungals

In which patient population are fungal infections most likely to occur and potentially become chronic?

They are more likely to occur in patients who are immunocompromised

What are the two common groups of fungal infections?

The two common groups are candida-like and tinea infections

Which medications are used to manage mucocutaneous candidal infections?

They are managed with nystatin, clotrimazole, ketoconazole, or fluconazole

What areas of the body does tinea affect, and what conditions does it produce?

Tinea affects the skin and produces athlete’s foot, “jock itch,” and ringworm

What is the typical duration for a course of treatment with antifungal agents?

The typical treatment course is 2 weeks

How do antifungal agents generally affect the efficacy of oral contraceptives?

They usually decrease oral contraceptive (O.C) efficacy

What is the most common fungal organism responsible for superinfections or suprainfections in dental patients?

Candida albicans (C.albicans)

What are the three main pre-disposing factors for a Candida albicans infection?

1) Chronic antibiotic use, 2) immunocompromised status (due to chemotherapy, radiation, HIV

What type of antifungal agent is nystatin?

It is a natural, polyene antifungal

Why is there a warning not to confuse nystatin with "statin" medications?

Because "statin" medications are used for cholesterol, whereas nystatin is an antifungal

Is nystatin fungicidal or fungistatic?

It is both fungicidal and fungistatic

What are the primary gastrointestinal adverse reactions associated with nystatin?

Nausea, vomiting, and diarrhea

Why should caution be used when prescribing nystatin oral suspension to diabetic patients?

Because the aqueous suspension formulation contains 50% sucrose (sugar)

What is the standard prescription instruction (Sig) for nystatin aqueous suspension to treat oral candidiasis?

Swish, swirl, and spit or swallow 5 ml four times daily

How long should nystatin suspension remain in the mouth to achieve the best therapeutic effect?

It should remain in the mouth for 2 minutes

What is the major drug-drug interaction mechanism shared by synthetic "azole" antifungals?

They are significant inhibitors of liver cytochrome P450 enzymes

Which antifungal agent requires high stomach acidity for proper absorption, and what is recommended to drink with it?

Ketoconazole (Nizoral) requires high acidity and should be taken with cola

What common over-the-counter medication decreases the absorption of ketoconazole?

Antacids (e.g Tums)

What serious systemic toxicity is associated with ketoconazole use?

Hepatotoxicity (liver toxicity)

What is the daily dosage and duration of ketoconazole for treating oral Candida?

200 to 400 mg orally daily for at least 2 weeks

How long might a patient need to take ketoconazole for chronic mucocutaneous candidiasis?

6 to 12 months may be required

What formulation of clotrimazole (Canesten) is used, and what is its clinical concern?

It is available as lozenges with high sugar content, which requires caution in diabetic patients

What are the specific adverse reactions associated with clotrimazole (Canesten)?

Abdominal pain, diarrhea, nausea, and xerostomia (dry mouth)

In which two patient groups is clotrimazole contraindicated or used with extreme caution?

Diabetics and children

What is the clinical advantage of using fluconazole (Diflucan) over other azoles?

It offers improved safety and predictable absorption

Which topical antiviral medication is not approved for use in patients under 12 years of age?

Abreva (docosanol)

At what stage of a viral herpes simplex lesion are antiviral medications most effective?

During the prodromal stage

What is the spectrum of action for acyclovir (Zovirax)?

HSV #1, HSV #2, HHV #3, HHV #5, and EBV

What adverse reactions are specifically associated with the topical route of acyclovir?

Burning and itching

What adverse reactions are associated with oral acyclovir administration?

Nausea, vomiting, and diarrhea

What rare but severe adverse reaction can occur with intravenous injection of acyclovir?

Seizures

Why is topical Zovirax ointment preferred over systemic antivirals for managing frequent mild HSV #1 lesions?

To avoid the severe adverse reactions associated with systemic antiviral prescriptions

What opportunistic infections are commonly associated with an HIV-positive status?

Tuberculosis (Tb), HSV, C. albicans, pneumonia, and flu virus

What infection must a dental professional always check for in an HIV-positive patient?

Candida albicans

What is the clinical term for the drug "cocktail" used to treat HIV-positive patients?

Highly Active AntiRetroviral Treatment (HAART) or AntiRetroviral Treatment (ART)

What is Azidothymidine (AZT), and what are its primary systemic adverse reactions?

It is an antiretroviral drug used for HIV treatment that can cause bone marrow depression and CNS effects (headache, agitation, insomnia)

What are the oral manifestations associated with Azidothymidine (AZT) therapy?

Taste perversion, edema of the tongue, bleeding gums, mouth ulcers, and pigmentation of the oral mucosa

What is the target CD4 count required for safe dental treatment of an HIV-positive patient?

It should be greater than 200 cells/mm

What is the minimum acceptable platelet count for treating an HIV-positive patient?

It should be greater than 60,000/mcl

Below what absolute neutrophil count (ANC) does an HIV-positive patient require prophylactic antibiotics?

Less than 500 cells/mcl

What is the target viral load number for an HIV-positive patient?

It should be less than 3,000/mcl

What is the acceptable therapeutic range for INR if an HIV-positive patient has co-morbidities or is taking Coumadin?

An INR between 2 and 3; do not treat if it is greater than 3

What HbA1c percentage indicates poorly controlled blood sugar in a diabetic patient?

Greater than 8%