Pharmacology Notes for Dental Hygiene

Focuses on the management of fungal (e.g., Candida albicans) and viral (e.g., herpes simplex) infections in dental practice.
Discusses AIDS and hepatitis B and C, emphasizing factors affecting dental treatment.
Antibiotics and anti-infectives target bacteria and other organisms but are ineffective against fungi and viruses.

Overview
Fungal infections are rare but challenging to treat, especially in immunocompromised patients.
Types of fungal infections include:
- Mucocutaneous: Affect skin/mucosa.
- Systemic: Spread throughout the body.
Treatment
Common antifungals include:
- Nystatin
- Clotrimazole
- Ketoconazole
- Fluconazole
Antifungals can be topical (for mucosal lesions) or systemic (for severe infections).

Mechanism of Action
It binds to sterols in the fungal cell membrane, increasing permeability and causing constituent leakage.
Administration
Not absorbed from mucous membranes or intact skin; poorly absorbed orally and excreted unchanged.
Adverse Reactions
Minor, can include nausea, vomiting, and diarrhea at high doses. Hypersensitivity reactions are rare.
Uses
Treatment and prevention of oral candidiasis.
Dental hygienists should educate patients on the cariogenic potential of certain forms (sugar content in lozenges).

Use in Dentistry
Clotrimazole (Mycelex) and Ketoconazole (Nizoral) are useful antifungals.
Fluconazole (Diflucan): An oral antifungal for oropharyngeal, esophageal candidiasis, and serious systemic infections.

Formulations: Oral lozenge and topical cream.
Mechanism: Alters cell membrane permeability; binds to the fungal cell membrane's phospholipids.
Side Effects: GI issues (abdominal pain, diarrhea, nausea), not recommended for pregnant women or children under 3.

Mechanism: Alters membranes by disrupting ergosterol synthesis.
Adverse Effects: GI disturbances, potential hepatotoxicity, and drug interactions (e.g., with warfarin).

Mechanism: Inhibits ergosterol synthesis; treats serious systemic infections and vaginal candidiasis.

Challenges in developing antiviral drugs due to the need to target specific viral processes without harming host cells.
Herpes Simplex Infections
Common in dental settings; include drugs such as Acyclovir, Docosanol, Penciclovir, and Famciclovir.

Mechanism: Inhibits DNA replication; selective uptake by infected cells reduces toxicity to healthy cells.
Adverse Effects: Headache, CNS effects (dizziness, fatigue), GI issues, and potential for topical irritation.

Over-the-counter topical agent that shortens healing time for oral herpes lesions (if used early).

Reduces duration and pain of herpes simplex lesions; higher efficacy in cells compared to Acyclovir.

Prodrugs that convert to Penciclovir and Acyclovir, respectively, and treat genital herpes and varicella-zoster infections.

Overview: Results from HIV infection; requires management with combinations of antiretroviral agents.
Drug Classes:
NRTIs, NNRTIs, protease inhibitors, fusion/entry inhibitors, and integrase inhibitors.

Zidovudine (AZT, Retrovir): First NRTI; effective at inhibiting HIV but has bone marrow toxicity and several side effects.

Examples: Nevirapine; specific for HIV-1 but can lead to quick resistance if used alone.

Saquinavir (Invirase): Important in AIDS treatment but can cause adverse reactions, including buccal mucosal ulceration.

Raltegravir (Isentress): Halts viral replication by blocking the integration of viral DNA into host DNA.

Combination Therapy: Utilizes various classes of drugs to suppress HIV replication effectively.

Most common causes of chronic hepatitis.
Treatment options include nucleoside/nucleotide analogs and interferons.
Nucleoside Analog Examples: Tenofovir, Entecavir, and Lamivudine.
Interferons: Approved for chronic hepatitis treatment; has immunomodulating effects but can lead to serious reactions.

Examples: Boceprevir and telaprevir, combined with interferons to enhance treatment efficacy.