Antitubercular, Antifungal, and Non-HIV Antiviral Pharmacology

Flashcards covering clinical pharmacology, mechanisms, adverse effects, and treatment regimens for antitubercular, antifungal, and non-HIV antiviral medications.

Mycobacterium tuberculosis

An acid-fast bacillus transmitted via airborne droplets (coughing, sneezing, speaking) that causes tuberculosis infection primarily in the lungs.

Latent Tuberculosis Infection

A condition in which a person is infected with Mycobacterium tuberculosis but does not have active symptoms, cannot transmit the bacteria to others, and remains at risk of developing active TB disease later.

Active Tuberculosis

Symptomatic disease caused by Mycobacterium tuberculosis characterized by anorexia, cough with blood-tinged sputum, chest pain, fever, night sweats, weight loss, and positive sputum acid-fast bacilli.

Streptomycin

An aminoglycoside antibiotic that was the first drug used to treat tuberculosis; it is now utilized for multidrug-resistant tuberculosis and can cause ototoxicity, nephrotoxicity, and optic nerve toxicity.

First-Line Antitubercular Drugs

The primary group of antitubercular medications—consisting of rifampin, isoniazid (INH), pyrazinamide, and ethambutol—which are considered more effective and less toxic than drug-resistant TB agents.

Rifampin

A first-line rifamycin class antitubercular agent whose adverse effects include turning body fluids orange, permanently discoloring soft contact lenses, thrombocytopenia, and GI intolerance.

Isoniazid (INH)

A first-line oral antitubercular drug that inhibits tubercle cell wall synthesis and blocks pyridoxine; adverse effects include liver damage, peripheral neuropathy, hyperglycemia, hyperkalemia, hypophosphatemia, and hypocalcemia.

Pyridoxine (Vitamin B6)

A supplement prescribed alongside isoniazid (INH) to prevent vitamin B deficiency and minimize drug-induced peripheral neuropathy.

Pyrazinamide

A first-line antitubercular medication that can cause arthralgia, myalgia, hepatotoxicity, and thrombocytopenia, requiring monitoring of liver function tests and serum uric acid.

Ethambutol

A first-line antitubercular drug that must be taken as a single dose with food; adverse effects include eye damage altering color and visual acuity, dizziness, confusion, hallucinations, joint pain, thrombocytopenia, and toxic epidermal necrolysis.

Direct Observation Therapy (DOT)

A supervised patient-management strategy used to ensure adherence and compliance with prescribed antitubercular drug regimens.

Initial Phase of Antitubercular Therapy

The first phase of standard tuberculosis treatment, lasting 2 months, which is followed by a continuation phase lasting 4 to 7 months.

Amphotericin B

A highly toxic polyene antifungal administered intravenously in low doses for severe, life-threatening systemic fungal infections; binds fungal cell membranes to form open leaking channels, causing nephrotoxicity, bone marrow toxicity, and electrolyte wasting (hypokalemia and hypomagnesemia).

Nystatin

A polyene antifungal administered orally or topically to treat Candida infections; its oral suspension is commonly swished in the mouth (and gargled if the throat is involved) to treat oral thrush.

Azole Antifungals

A class of oral and topical antimycotics (including fluconazole, ketoconazole, itraconazole, posaconazole, and voriconazole) that treat candidiasis and tinea infections by inhibiting fungal cytochrome P450, thereby interfering with ergosterol formation.

Flucytosine

An oral antimetabolite antifungal that selectively penetrates fungal cells and converts into fluorouracil to disrupt fungal DNA and RNA synthesis; commonly combined with amphotericin B.

Echinocandins

The newest class of intravenously administered antifungals (including anidulafungin, caspofungin, and micafungin) that inhibit the biosynthesis of essential fungal cell wall components.

Phlebitis

Inflammation of a vein at the IV site, which represents a common adverse effect associated with intravenous echinocandin therapy.

Virus

An obligate intracellular organism that must reside and reproduce inside living host cells, utilizing host DNA and RNA to replicate.

Neuraminidase Inhibitors

A group of anti-influenza drugs (oseltamivir and zanamivir) that block viral neuraminidase, decreasing viral release from infected cells; they must be administered within 48 hours of symptom onset.

Oseltamivir

An oral neuraminidase inhibitor effective against influenza types A and B; requires close monitoring for abnormal behavioral changes as well as dizziness, insomnia, and gastrointestinal disturbances.

Acyclovir

An antiviral agent used to treat herpes simplex viruses (HSV-1, HSV-2) and varicella-zoster virus (chickenpox and shingles); IV formulations must be infused over at least 60 minutes and never given via bolus or IV push.

Ganciclovir

The first approved antiviral medication specifically indicated for the treatment of cytomegalovirus (CMV) retinitis in immunocompromised patients, such as those with AIDS.

Cidofovir

An antiviral drug that suppresses viral replication by inhibiting viral DNA polymerase, used in combination therapies to treat CMV retinitis.

Hepatitis B Virus (HBV) Antivirals

Agents including lamivudine, adefovir, entecavir, tenofovir, and peginterferon alfa-2a that suppress viral progression in chronic hepatitis B, although none provide a cure.

Hepatitis C Virus (HCV) Antivirals

Combination therapies—which may incorporate peginterferon alfa-2a, NS5A inhibitors (ledipasvir), and polymerase inhibitors (sofosbuvir)—used to treat chronic HCV infection to prevent cirrhosis, liver failure, and hepatic carcinoma.

Peginterferon alfa-2a

An injectable antiviral agent used in chronic viral hepatitis; adverse effects include depression, fatigue, flulike symptoms, pancytopenia, alopecia, arthralgia, myalgia, thyroid dysfunction, and ophthalmic complications.

Ribavirin

An antiviral agent that is teratogenic and can cause hemolytic anemia; used in the management of specific viral infections including hepatitis.