Drugs Used In Liver Diseases

Question 1

What are the drugs to treat cholecystitis and their MOA?

Answer 1

1) Ceftriaxone
- B-lactam antibiotic
- Inhibits bacterial cell wall synthesis
- Covers against Gram + and - bacteria (broad spectrum)

2) Metronidazole
- DNA synthesis inhibitor
- Disrupts nucleic acid synthesis via oxidative stress
- Good coverage against protozoans and anaerobes

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- Oral dissolution therapy (meds from bile acid used to dissolve the stones)
- Low-fat diet
- Cholecystectomy (gladder removal)
- Laparotomy (examine to examine the inside of the abdomen and organs)

Question 2

What are the adverse effects of ceftriaxone and metronidazole?

Answer 2

• Ceftriaxone
  ~ Rash and diarrhoea
• Metronidazole
  ~ Thrombophlebitis
  ~ Dizziness, headache, abdominal pain, metallic taste, nausea, anorexia
  ~ Need to avoid alcohol (including mouthwash)

Question 3

What happens in chronic cholecystitis?

Answer 3

• May not have symptoms
• Damaged gallbladder walls which become scarred and grow thicker
  ~ Due to small gallbladder, it will be less able to store and release bile

Question 4

What is the pharmacotherapy of Hepatitis A?

Answer 4

• Cannot be cured
• Vaccination before exposure
• Post-exposure prophylaxis (PEP) with Hep A immunoglobulin

Question 5

What is the pharmacotherapy for Hepatitis B?

Answer 5

• No cure, but can vaccinate
• For recent exposure, give Hep B Ig PEP
• For chronic exposure, give 4 months of Interferon-alpha or PEG interferon
  ~ Include long-term nucleoside inhibitors (Entecavir, Tenofovir and Lamivudine)
• Entecavir is taken 1x/day and has the least side effects
• Tenofovir is used in HIV treatment to reduce viral load

Question 6

How does nucleoside reverse transcriptase inhibitor work?

Answer 6

• Blocks reverse transcriptase from converting Viral RNA to Viral DNA for bacterial multiplication
• Slows down growth of virus (tf decrease liver damage)
• Hep B replicates like HIV viruses

Question 7

What is the pharmacotherapy for Hep C?

Answer 7

• No vaccine available
• Not recommended to get PEP
• No treatment available for acute hep C
• Give Interferon-alpha or PEG interferon for 4 months if chronic exposure
• Use Protease inhibitor (Anti-HCV) for the long-term
  ~ Elbasvir/grazoprevir

Question 8

What is the MOA of Anti-HCV?

Answer 8

• Binds to proteolytic enzymes
  ~ Blocks ability of enzyme to function and stops HCV from reproducing itself to keep the viral load low

Question 9

What is the treatment for liver failure or liver cirrhosis?

Answer 9

• Stop all drugs that can induce liver injury
• Use antidote N-acetylcysteine
  ~ Reverses the toxic effect of acetaminophen overdose
  ~ Prevents acute liver failure
  ~ Has antioxidant activity
• Spironolactone and Furosemide
  ~ Relieves pressure caused by excess fluid
• Lactulose laxative
  ~ To flush out toxins
• Rifaximin and Ciproflaxacin antibiotics
  ~ For spontaneous bacterial peritonitis
  ~ (R) Negligible impact on intestinal microbiome
  ~ (C) DNA synthesis inhibitor

Question 10

What drugs do px with liver failure/cirrhosis need to avoid?

Answer 10

1) Acetaminophen
~ ^ risk of hepatotoxicity due to toxic metabolites (N-actyl-p-benzoquinone imine)
~ Max dose is 2000mg

2) Azithromycin, erythromycin and clindamycin
~ ^ hepatotoxicity and mortality

3) Methotrexate
~ Hepatotoxicity due to folate depletion
~ Requires frequent monitoring if therapy is required

4) Anti-TB drugs, pyrazinamide

5) Herbal supplements
~ Green tea extract associated with liver injury

6) Abacavir, COX-2 inhibitors, NSAIDs, anticoagulants, setraline and tacrolimus