Exam iii - antimycobacterial and antiviral (non-HIV) drugs

what are the four antimycobacterial drugs?

isoniazid, rifampin, pyrazinamide, ethambutol

isoniazid is both bactericidal and bacteristatic, what is isoniazid bactericidal to?

actively dividing bacteria

isoniazid is both bactericidal and bacteristatic, what is isoniazid bacteriostatic to?

to "resting" TB organisms

what is the indications for use for isoniazid?

non-resistant forms of M. tuberculosis

what is the MOA for isoniazid?

not specifically known; inhibits synthesis of mycolic acid needed ot build the cell wall

should isoniazid be used alone?

No, a multi-drug approach is required

what are the 2 AE of isoniazid?

peripheral neuropathy and hepatotoxicity

is the patient is experiencing peripheral neuropathy from taking isoniazid, how can that be treated?

vitamin B6

what are 2 drug interactions for isoniazid?

p450 inhibitor and alcohol

why should you not drink alcohol when taking isoniazid?

it increases risk for liver injury

because hepatotoxicity is an AE of isoniazid, what should you monitor?

liver function

is rifampin broad or narrow spectrum? bacteriostatic or bactericidal?

broad, bactericidal

what is the MOA of rifampin?

inhibits DNA/RNA enzymes to suppress RNA synthesis, whic will result in no protein synthesis

what are the 3 therapeutic uses for rifampin?

TB, s. aureus, and leprosy

what are the 3 AE for rifampin

discoloration of body fluids, hepatotoxicity, and RARELY hepatitis

does rifampin induce or inhibit P450?

induce

rifampin can induce P450 for what 3 meds?

oral contraceptives, warfarin, and drugs for HIv infections

because rifampin can induce P450 metabolism for oral contraceptives, what can you educate the patient?

look for a contraceptive alternative

what is the MOA for pyrazinamide?

unknown

is pyrazinamide bactericidal or bacteriostatic? and to what one bacteria?

bactericidal, M. tuberculosis

what is the therapeutic use for pyrazinamide?

TB

one of the AE of pyrazinamide is hepatotoxicity, but its risk for that increases when used in combination with either what or what?

isoniazid and rifampin

what are 2 AE of pyrazinamide?

hepatotoxicity and polyathralgias

if the pt is experiencing polyathralgia, what are 2 things that you can do to manage it?

manage with NSAIDs and decrease the dose

what is the MOA of ethambutol?

supresses the incorporation of mycolic acid into bacterial cell wall

is ethambutol bacteriostatic or bactericidal? and against what?

bacteriostatic, mycobacteria

in terms of pharmacokinetics, how is ethambutol metabolized and how much?

minimal hepatic metabolism

what is the most significant AE of ethanmbutol

optic neuritis

because of the risk fo optic neuritis from ethanbutol, what age group should not be given ethambutol?

<8yo

how do you resolve optic neuritis from ethambutol?

discontinuation

what is the primary indiction of use for acyclovir?

herpesvirus group

does acyclovir treat HIV

no

what is the MOA for acyclovir?

inhibition of viral replication by suppression of viral DNA

in order for acyclovir to work, it must be activated by what?

thymidine kinase

how does acyclovir suppress viral DNA

it inactivates dna POLYMERASE AND BLOCKS dna STRAND GROWTH

how is acyclovir administered? 3

oral, topical, IV

how is acyclovir eliminated?

renal

what are the AE of acyclovir when administered topically? 2

burning and stinging at the site of administration

what are the AE of acyclovir when administered orally? 5

n/v/d, h/a, vertigo

what are the AE of acyclovir when administered IV? 3

phlebitis, reversible nephrotoxicity, and neurologic toxicity

because acyclovir is eliminated renally, this may be affected by pts with a renal impairment, which increases the risk for nephrotoxicity. how long should you infuse?

slowly over 1h

what labs should you monitor for nephrotoxicity?

serum creatinine and BUN

is is the MOA for oseltamivir?

it inhibits neuraminidase to impact viral replicationby preventing the cleaving of new virus to be released

what kind of drug is oseltamivir if it needs to be hydrolyzed?

prodrug

what are the indications of use for oseltamivir?

seasonal influenze and influenza A

how is oseltamivir administered and when?

orally within 48h of symptom onset

how is oseltamivir letabolized and excreted?

metabolized by the liver, excreted renally

what are the GI AE for oselatmivir?

n/v/d

what are the neuropsychiatric effects for oseltamivir?

delirium, confusion, hallucination

what are the hypersensitivity reaction for oseltamivir?

steven-johnsons syndrome

what two medications work in combination to create paxlovid?

nirmatrelvir and ritonavir

what is the MOA for nirmatrelvir?

protease inhibitor preventing processing of polyprotein precursors needed for viral replication

what is the MOA for ritonavir?

pharmacokinetic enhancer for nirmatrelvir, has no activity against the virus

what are the indications of use for paxlovid?

mild to moderate covid 19 and non-hospitalized patients with risk of progression to severe illness

how is paxlovid administered? when?

orally within 5d of sx onset

in terms of pharmacokinetics, paxlovid is an inhibitor of what?

P450 CYP3A

how is paxlovid excreted?

renally

what 2 types of AE can occur in paxlovid?

hepatic and hypersensitivity

what are the 2 types of hepatic AE that can occur when taking paxlovid?

hepatitis and elevation of transaminases

what are the 2 types of hypersensitivty reactions AE that can occur when taking paxlovid?

anaphylaxis and steven-johnsons syndrome

does paxlovid treat HIV?

no

does oseltamivir treat HIV?

no