Isoniazid (INH)

• primary drug for prophylaxis and tx of TB
  
• mechanism of action: highly selective for M. tuberculosis. Bactericidal to bacilli that are actively dividing. Bacteriostatic to dormant. Likely suppresses growth by inhibiting synthesis of mycolic acid for cell wall, which is not produced by the host or other bacteria.
  
• PO/IM
• therapeutic uses: used to treat active TB along with another drug, or alone to treat LTB
• adverse effects: peripheral neuropathy (give pyridoxine-Vitamin B6) and hepatotoxicity, (stop tx)
  
• do not take with phenytoin

Rifampin (Rifadin)

• mechanism of action: broad spectrum against most gram (+) and some (-). suppresses protein synthesis by inhibiting DNA-dependent RNA. Bactericidal to M. tuberculosis and M. leprae.
• drug effects: inducer of P450 enzymes, can decrease the levels of many drugs, especially oral contraceptives, warfarin, and protease inhibitors and NNRTIs (for HIV)
• PO/IV
• therapeutic uses: one of the most effective against TB, both intra- and extracellular. drug of choice for pulmonary and disseminated TB. never used alone.
  
• side effects: toxicity rarely causes discontinuation of tx, hepatotoxicity. Gives a red-orange color to urine, sweat, saliva and tears.
  

Pyrazinamide(PZA)

• mechanism of action: UNK, bactericidal
• PO
  
• therapeutic uses: used with rifampin, isoniazid and ethambutol for first 2 months of tx for active TB. alternative tx for LTB. Do not use in pregnant women (effect on fetus is unknown)
• side effects: hepatotoxicity

Ethambutol (Albutol)

• mechanism of action: suppresses incorporation of mycolic acid into cell wall. bacteriostatic to mycobacteria (including TB), active against strains resistant to INH and refampin.
• PO
  
• therapeutic uses: used with INH, rifampin and PZA for first 2 months of tx of active TB. used for those who have been treated previously.
  
• side effects: optic neuritis, causes blurred vision, constriction of visual field, and poor color discrimination. Stop tx if symptoms occur. Usually resolves when tx is discontinued. not for children <8yoa

Amphotericin B (amphotec)

• polyene antibiotics
• increases cell permeability
• broad spectrum of pathogenic fungi, drug of choice for systemic mycoses
• preferably used in the hospital, to monitor for effects
• tx is usually 6-8 weeks
• adverse effects:
• fever, chills, rigors, nausea and headache
• high incidence of phlebitis
• nephrotoxicity
• minimized by administering 1L of saline daily during tx
• hypokalemia
• bone marrow suppression
• do not take with NSAIDs, cyclosporins or aminoglycosides
• monitor, BUN, creatinine, I&O, potassium, hematocrit
• infuse slowly over 2-4 hours, rotate sites of infusion
• pre-treat with tylenol and benadryl

AZT/Zidovudine (Retrovir)

• mechanism of action: (NRTI) Suppress synthesis of viral DNA by reverse transcriptase. must undergo conversion to active form, ZTP, which is incorporated into forming viral DNA, stopping further growth. also causes competitive inhibition of reverse transcriptase.
• drug effects: decrease viral load, increase CD4 T cell counts, delay onset of disease symptoms and reduce symptom severity
• therapeutic uses: used in combination of other drugs for HIV. able to penetrate into CNS
• PO/IV
• key side effects:
• anemia and neutropenia
•  Lactic acidosis with severe hepatomegaly (liver enlargement) and hepatic steatosis(fatty degeneration of liver).
  
• lab values: monitor hemoglobin, neutrophil counts before tx and every 2-4 weeks after. lactic acid levels in arterial blood. AST/ALT

efavirenz (sustiva)

• mechanism of action: NNRTI, not an analog of natural nucleosides, are active as administered, causes direct non-competitive inhibition of reverse transcriptase by binding to its active center
• therapeutic uses: used in combination with other drugs for HIV
• PO
• key side effects:
• CNS symptoms occur in over 50% of patients.
  
• rash is common, mild to severe. rarely, stevens-johnson syndrome may develop. should be withdrawn if rash is severe.
• teratogenic, use both barrier and hormonal birth control
• liver damage
• pertinent patient teaching: take on an empty stomach, must know they can still
• lab values: AST/ALT

lopinavir (kaleta)

• mechanism of action: protease inhibitor, binds to HIV protease, preventing the virus from cleaving HIV polyproteins. enzymes and structural proteins of HIV remain non-functional, so virus is immature and noninfectious
• therapeutic uses: used in combination with other drugs for HIV in adults and children over 6 months
• PO
• key side effects:
• Most common: diarrhea, nausea, headache, weakness and tiredness
• risk of hyperglycemia, new-onset diabetes, or exacerbation of existing DM
• fat maldistribution
• reduced bone density
• increased bleeding in pts with hemphilia
• rash in children
• inhibits P450, decreasing the metabolism of all drugs.
• patient teaching: take with food, may still infect others with HIV

Acyclovir (Zovirax)

• mechanism of action: suppresses synthesis of viral DNA, by inhibiting viral DNA polymerase and incorporating into the growing strand of viral DNA. selective as only certain viruses activate the drug
• therapeutic uses: drug of choice for herpes simplex viruses(on genitals, face or oropharynx) and varicella-zoster virus(chickenpox and shingles).
• PO/TP/IV
• key side effects: phlebitis and inflammation if given IV. reversible nephrotoxicity, worsened by dehydration(infuse slowly with extra fluids). oral admin may cause N/V/D, headache and vertigo. topical may cause burning or itching.
• patient teaching: apply topical agent with a finger cot or glove to prevent spread

Influenza Vaccine

Rimantadine (flumadine)

• mechanism of action: thought to inhibit replication at an early step
• therapeutic uses: prophylaxis (only in high risk pts or helath care workers) and tx of influenza A. not for use in children, except as prophylaxis.
• key side effects: CNS, dizziness, nervousness, insomnia, or more serious
• patient teaching: can increase the effect of anticholinergic drugs
• pregnancy: crosses the placenta, avoid in pregnant women

Zanamivir (Relenza)

• mechanism of action: inhibits an enzyme required for viral replication
• drug effects
• therapeutic uses: prophylaxis of influenza in those at least 5 yoa, shortens duration of flu in those with acute, uncomplicated flu at least 7 yoa
• key side effects: if pt has asthma or COPD, may cause bronchospasm and respiratory decline. cough or sore throat.