HIV/TB Flashcards
Isoniazid MOA
Bactericidal against active TB
Bacteriostatic against dormant TB
Isoniazid Use
Latent TB
Active TB 1st line
Isoniazid A/E
Peripheral neuropathy (from B6 deficiency) -MC N/D Dizziness Optic neuritis Seizures
Isoniazid Pt edu
Take Vit B6 (pyridoxine) to prevent peripheral neuropathy
Limit alcohol intake
Can develop resistance
Isoniazid Toxicity
Hepatotoxic
-monitor for anorexia, malaise, yellowing of eye
may need to stop drug
Isoniazid Monitoring
SxS of hepatotoxicity
LFTs
Monthly
Direct observation therapy
Administration of each dose is carried out in the presence of an observer
By the Health department
Preferred
Intermittent Dosing
Can be done at home 2-3 times a week dosing Larger doses but less frequently No additional risk for A/E As effective as daily dosing
Latent TB Standard Tx
Isoniazid daily for 9mo - self administered
Latent TB Tx for allergy to Rifampin
Isoniazid and Rifapentine once weekly for 3 mo
DOT
Not safe for everyone
Active TB Induction phase
Eliminate actively dividing extracellular TB
Rifampin, Isoniazid, Ethambutol, Pyrazinamide x2mo
Active TB Continuation phase
Eliminate intracellular “persisters”
Rifampin and Isoniazid x4.5 mo
May last longer
Drug resistant TB
Inherent resistance, Development of resistance during tx, Inadequate drug therapy
Tx can be up to 24 mo
TB Tx Goal
Cure, prevent spread to others
Rifampin MOA
Suppresses RNA synthesis and protein synthesis
Inhibits bacterial DNA- dependent RNA polymerase
Rifampin Use
Broadspectrum abx
1st line Active Tb
Kills active and semi-dormant TB
Rifampin Drug interactions
CYP3A4 Warfarin PO BC Protease inhibitors NNRTI -All decrease effect of Rifampin
Rifampin A/E
Red-orange body fluids (every body fluid, wear glasses because it will stain contacts)
N/V/D
Flu-like symptoms
Pruritus
Rifampin Toxicity
Hepatotoxicity
Rifampin Pt edu
Use barrier method of sexual protection
Rifampin Monitoring
Drug resistance
LFTs
Pyrazinamide Use
1st line Active TB
Pyrazinamide A/E
Non Gouty polyarthralgias
N/V/D
Rash
Pyrazinamide Toxicity
Hepatotoxic
Pyrazinamide Contraindications
Liver disease
Pyrazinamide Pt edu
Limit alcohol
Manage polyarthralgias with NSAIDS (ibuprofen or aspirin)
Pyrazinamide Monitor
LFTs
-before and 2 weeks after
Ethambutol MOA
Bacteriostatic- stops from reproducing
Suppresses incorporation of mycolic acid in the cell wall
Ethambutol Use
1st line active TB
Previously treated with other drugs
Resistant to Isoniazid and/or Rifampin
Ethambutol A/E
Optic neuritis (blurred vision, constriction of visual field, disturbance of color) -especially in children
Ethambutol Contraindications
Children under 8 - due to optic neuritis
Ethambutol Pt edu
Monitor vision changes
Take food if GI upset
Ethambutol Monitoring
Monthly
Blurred vision
Color discrimination
Visual field disturbances
TB and HIV considerations
May require longer durations of treatment
At risk for developing immune reconstitution syndrome (IRIS) - exaggerated inflammatory response (another infection)
Drug interactions
TB Vaccine
BCG: only given in countries with high rates of TB and only given to children, once given, they will always test positive on a PPD
Efavirenz interaction with Rif
Least interactions
Protease inhibitors interaction with Rif
Replace Rif with Rifabutin
Raltegravir interaction with Rif
Increase dose of Raltegravir
Dolutegravir interaction with Rif
Increase Dolutegravir frequency
Maraviroc interaction with Rif
Increase Maraviroc dose
Acyclovir MOA
Inhibits viral replication by suppressing synthesis of viral DNA
Activation of acyclovir to acycloguanosine monophosphate (GMP) by thymidine kinase (GTP), the compound directly responsible for inhibiting DNA synthesis
Acyclovir Use
1st line for HSV, VZV
HSV type 2
Prophylaxis in immunocompromised pts
Not a cure, only treatment of symptoms as they happen
Acyclovir A/E IV
Phlebitis
Inflammation