Antituberculars, Antifungals, Antivirals, Antimalarials, Anthelmintics and Peptides

Flashcards covering key concepts, facts, and details related to pharmacology, focusing on antituberculars, antifungals, antivirals, antimalarials, anthelmintics, and peptides.

What causes tuberculosis (TB)?

Mycobacterium tuberculosis — an acid-fast bacillus.

How is TB transmitted?

Person to person via respiratory droplets (coughing, sneezing, talking).

Who is at risk for TB?

Immunocompromised individuals, people in high-risk residential settings, IV drug users, and healthcare workers with high-risk patients.

What are the symptoms of active TB?

Cough with blood-tinged sputum, fever, night sweats, anorexia, weight loss, chest pain, and positive acid-fast bacilli in sputum.

What is latent TB infection?

Asymptomatic TB where the person cannot spread the disease but has a risk of developing active TB later.

What is the best way to reduce TB transmission?

Identify, isolate, and treat — using an N95 mask, testing family members, and treating for 6–12 months.

What does BCG stand for, and why is it relevant to TB testing?

Bacille Calmette-Guerin — a vaccine given in high-risk countries. BCG-vaccinated patients will have a positive skin test, so an IGRA (interferon-gamma release assay) should be used instead.

What does IGRA stand for and when is it used?

Interferon-gamma release assay — used to test for TB in BCG-vaccinated patients where the skin test would be falsely positive.

What is the RIPE acronym for TB treatment?

Rifampin, INH (Isoniazid), Pyrazinamide, Ethambutol — the four first-line antitubercular drugs.

How many phases are in TB combination therapy?

Two phases: Phase 1 (2 months, all 4 drugs) and Phase 2 (4–7 months, fewer drugs).

Why is combination therapy used for TB?

It reduces drug resistance and shortens treatment time.

What is the mechanism of action of INH (Isoniazid)?

Inhibits tubercle cell wall synthesis and interferes with pyridoxine (Vitamin B6) metabolism.

What are the key side effects of INH?

Peripheral neuropathy (from B6 depletion) and hepatotoxicity.

What supplement must be given with INH and why?

Vitamin B6 (pyridoxine) 25–50 mg or B-complex daily — to prevent peripheral neuropathy caused by INH's interference with B6 metabolism.

How should INH be taken in relation to food?

1 hour before or 2 hours after meals — food slows oral absorption.

What should patients avoid while taking INH?

Alcohol — increases risk of hepatotoxicity.

What labs must be monitored closely with INH?

Liver function tests (LFTs).

What is a distinctive side effect of Rifampin?

It turns body fluids (urine, sweat, tears, saliva) orange.

What is a special precaution for Rifampin and contact lenses?

Soft contact lenses may be permanently discolored by rifampin — advise patients not to wear them.

What drug interaction does Rifampin have with contraception?

Rifampin interferes with oral contraceptives — patients must use an alternative form of birth control.

What are the side effects of Pyrazinamide?

Myalgias, joint pain, gout, and hepatotoxicity. Monitor LFTs and watch for symptoms of liver damage.

What organ does Ethambutol affect?

The eyes — it can cause optic neuritis and changes in vision or eye color.

What monitoring is required for patients taking Ethambutol?

A baseline eye exam and regular eye screening. Patients must report any changes in vision or eye color.

What is MDR-TB?

Multi-drug resistant TB — resistant to INH and rifampin plus at least one other first-line drug.

What causes MDR-TB to develop?

Patients mismanaging or misusing their medications — especially starting and not finishing therapy, allowing resistant strains to develop and spread.

How is MDR-TB treated?

With 4–5 drugs, sensitivity testing, and management by an expert in the field. First-line treatment should not be delayed.

What is DOT and why is it used?

Direct Observation Therapy — a strategy where a healthcare worker watches the patient take their medication to ensure adherence and prevent drug resistance.

Who should receive TB prophylaxis?

Those with latent TB infection, immunocompromised patients, positive tuberculin skin test (>=5mm immunocompromised / >=10mm high-risk), positive IGRA, or a TB test that converted from negative to positive.

What is a contraindication to TB prophylaxis?

Liver disease.

What is the prophylactic INH dose for latent TB?

5 mg/kg/day up to 300 mg/day, or 15 mg/kg twice weekly. Do not give with food.

Name common side effects shared across antitubercular drugs.

Headaches, dizziness, confusion, hallucinations, peripheral neuropathy, GI distress, hyperglycemia, hypocalcemia, hypokalemia, ocular toxicity, hepatotoxicity, nephrotoxicity, blood dyscrasias.

What are the special TB considerations during pregnancy?

Treatment outweighs the risk — risk of passing TB to the fetus and low birth weight makes treatment necessary.

Why is TB especially dangerous in HIV-positive patients?

TB is the leading cause of death in HIV patients. Both latent and active TB must be treated.

What causes fungal infections?

Contact with fungi — also called candidiasis, mycosis, or tinea depending on type.

What are examples of local (mild) fungal infections?

Oral candidiasis (thrush), vaginal candidiasis, tinea pedis (athlete's foot), and jock itch.

What are examples of systemic (severe) fungal infections?

Fungal lung infection (affecting lungs/abdomen) and fungal meningitis (affecting the CNS).

What are opportunistic fungal infections?

Infections that occur in immunocompromised or debilitated patients, or those on antibiotics, corticosteroids, or chemotherapy. Examples: candidiasis, aspergillosis, mucormycosis, pneumocystis pneumonia.

What are primary fungal infections?

Infections that usually occur in immunocompetent individuals via inhaled spores. Examples: blastomycosis, histoplasmosis, coccidioidomycosis, cryptococcosis.

What are the main classes of antifungal drugs?

Polyenes (Amphotericin B, Nystatin), Azoles (Fluconazole), Antimetabolics (Flucytosine), Echinocandins (Caspofungin), and Miscellaneous (Griseofulvin).

What is the mechanism of action of Amphotericin B?

Binds to fungal cell membranes, causing increased cell permeability and leakage of cellular contents.

What type of infections is Amphotericin B used to treat?

Severe, systemic fungal infections and CNS fungal infections.

What are the side effects of Amphotericin B?

Flushing, fever, chills, headache, dizziness, tachypnea, dyspnea, hypotension, GI distress, paresthesia, thrombophlebitis. High doses: nephrotoxicity, hypokalemia, hypomagnesemia.

When do infusion reactions to Amphotericin B typically begin?

1–3 hours after initiating the infusion.

How do you prevent infusion reactions to Amphotericin B?

Pretreat 30–60 minutes before the drug with acetaminophen, diphenhydramine, and hydrocortisone.

What labs must be monitored with Amphotericin B?

Creatinine (>1.3 indicates kidney damage), urine output (less than 30 mL/hr is concerning), potassium, and magnesium.

What is Nystatin used for?

Oral (thrush) and topical/vaginal fungal infections — it is not absorbed systemically so it cannot treat systemic infections.

What is the patient teaching for Nystatin oral suspension?

Swish and swallow — hold in the mouth as long as possible, then swallow. Symptom relief occurs within 24–72 hours.

What are the forms of Nystatin?

Oral suspension, cream, ointment, vaginal tablet, or suppository.

What is the mechanism of action of Azoles?

Interferes with ergosterol formation, increasing fungal cell membrane permeability and causing leakage.

Name examples of topical vs. systemic azoles.

Topical: clotrimazole, miconazole, ketoconazole. Systemic: ketoconazole, fluconazole, itraconazole, voriconazole, posaconazole.

What are the side effects of Azoles?

Headache, rash, GI distress, hypokalemia, dysrhythmias, hepatotoxicity, nephrotoxicity.

What does Fluconazole treat?

Candida infections and cryptococcal meningitis.

What is the key drug interaction of Fluconazole with sulfonylureas?

Fluconazole + oral sulfonylureas increases risk of hypoglycemia — monitor blood glucose closely.

What labs should be monitored with Fluconazole?

LFTs (may be elevated) and renal function — 80% excreted in urine.

What is Caspofungin used for and how is it given?

Esophageal candidiasis — given IV (echinocandin class).

What is Griseofulvin used for?

Tinea (ringworm/athlete's foot) infections — given orally.

What are the key nursing considerations for antifungals?

Assess hepatic and renal function, monitor urinary output, advise taking as prescribed, no alcohol, and report side effects.

How do viruses replicate?

They reside in living host cells and use the host's DNA/RNA enzymes and substrates to duplicate.

Are most viral infections self-limiting?

Yes — except HIV and viral hepatitis, which require ongoing treatment.

What is the mechanism of action of antivirals?

They inhibit viral replication — they do not kill the virus outright.

What are the three main types of common viral infections targeted by antivirals?

Influenza, herpes viruses, and hepatitis.

What are the three types of influenza and their severity?

Influenza A (moderate to severe), Influenza B (mild, usually in children), Influenza C (mild respiratory illness).

What are the signs and symptoms of influenza?

High fever (up to 104 F), headache, fatigue, weakness, myalgia, watery nasal discharge, red watery eyes, photophobia, chills, sore throat, and nonproductive cough.

Name the two main influenza antivirals.

Oseltamivir (Tamiflu) and Zanamivir (Relenza).

What is the critical time window for starting flu antivirals?

Must be started within 48 hours of symptom onset to be effective.

What do flu antivirals do?

Decrease viral spread and shorten duration of signs and symptoms.

What are the side effects of flu antivirals?

Dizziness, headache, insomnia, fatigue, GI distress, and abnormal behavior.

List the 5 herpes virus types and what they cause.

HSV-1 (cold sores, can be latent), HSV-2 (genital lesions), VZV/HSV-3 (chickenpox and shingles), EBV/HHV-4 (mononucleosis), CMV/HHV-5 (weakened immune system).

What causes shingles?

Varicella-zoster virus (VZV/HSV-3) — in adults who were previously exposed to chickenpox.

What class of drug is Acyclovir and what is its mechanism of action?

Nucleoside analogue — interferes with viral DNA synthesis.

What infections does Acyclovir treat?

HSV-1, HSV-2, and varicella-zoster viruses (chickenpox and shingles).

How is Acyclovir excreted and what nursing intervention does this require?

90–92% excreted unchanged in urine — promote hydration to prevent renal crystallization.

What is the priority nursing intervention for patients on antiviral drugs?

Promoting hydration — antivirals are renally excreted and hydration prevents nephrotoxicity.

What are CMV antivirals used for?

Cytomegalovirus retinitis in people with AIDS.

Name the four approved CMV antivirals.

Ganciclovir, valganciclovir, cidofovir, and foscarnet.

What is the mechanism of action of CMV antivirals?

Inhibit DNA polymerase to suppress viral replication.

What is a serious adverse effect of CMV antivirals?

Bone marrow suppression, blood dyscrasias, and renal dysfunction.

What nursing assessments are done before giving antivirals?

Obtain patient medical history including hepatic and renal disease. Monitor CBC for leukopenia, thrombocytopenia, low hemoglobin/hematocrit. Record urinary output.

What causes Hepatitis B and C?

Blood-borne pathogens — spread via blood and body fluids. HBV is a DNA virus; HCV is an RNA virus.

What are the signs and symptoms of hepatitis?

Fatigue, malaise, nausea, abdominal pain, and jaundice. Healthy adults may be asymptomatic.

Is there a vaccine for Hepatitis B and C?

Yes for HBV — no vaccine exists for HCV.

How is Hepatitis B transmitted?

Needle stick, intimate partner contact, and childbirth.

Name the five antivirals used for Hepatitis B.

Lamivudine, adefovir, entecavir, tenofovir, and peginterferon alfa-2a (non-nucleoside).

What do Hepatitis B antivirals do?

Inhibit viral replication and delay progression of liver disease.

What are the side effects of HBV antivirals?

Fatigue, flu-like symptoms, depression, alopecia, photosensitivity, anorexia, thyroid/ophthalmic dysfunction, hepatotoxicity, renal impairment, lactic acidosis, blood dyscrasias.

What population is Hepatitis C most prevalent in?

IV drug users.

How is Hepatitis C treated?

With NS5A inhibitors (e.g., ledipasvir), polymerase inhibitors (e.g., sofosbuvir), and peginterferon alfa-2a.

What is genotype testing for HCV?

Testing that identifies which of the 6 genotypes (and 50+ subtypes) a patient has — helps predict response to treatment.

What causes malaria?

A protozoan parasite carried by infected mosquitos.

What is the incubation period for malaria?

10–35 days, followed by flu-like symptoms.

How many malaria cases occur in the US annually and why?

2,000–2,500 cases per year — mainly in people who have traveled outside the US. Malaria was eliminated domestically in the early 1950s.

What are the three goals of malaria drug therapy?

Prophylaxis (prevention), treatment of acute attack, and prevention of relapse.

How is malaria prevented?

Controlling mosquitos via netting and spraying, and taking prophylactic drugs before traveling to endemic areas.

What is the mechanism of action of Chloroquine?

Antiprotozoal — interferes with the malaria parasite's protein synthesis to inhibit growth.

What is the prophylaxis dosing schedule for Chloroquine?

Once weekly, starting 1–2 weeks before entering an endemic area, and continuing for 4 weeks after leaving.

What are the contraindications for Chloroquine?

Hypersensitivity and ocular disease.

What are the side effects of Chloroquine?

Anorexia, nausea, vomiting, diarrhea, abdominal cramps, fatigue, pruritus, headache, nervousness, visual impairment, insomnia, photosensitivity, hair discoloration, yellowing of skin and eyes.

How is Chloroquine absorbed and metabolized?

Well absorbed orally and metabolized by the liver.

What are helminths?

Parasitic worms transmitted through poor sanitation, contaminated food, insect bites, or direct skin penetration.

What body systems do helminths affect?

The intestines, lymphatic system, blood vessels, and liver.