Drug Toxicity

Question 2

Name and describe the 3 mechanisms of drug toxicity.

Answer 2

1. On Target: toxicity usually results from dosing error (too much)2. Off Target: drugs activate receptors other than the target receptor (including subtypes of receptors)3. Idiosyncratic: unknown

Question 3

What is the “Class Effect” in relation to drug toxicity?

Answer 3

A toxic condition caused by one drug should be expected in all other drugs of the same class.

Question 4

Example of using drug-drug interactions for advantageous effect.

Answer 4

Probenecid inhibits metabolism of Penicillin allowing the antibiotic to work longer.

Question 5

Example of a negative effect from drug-drug interaction that can lead to hypotension and death.

Answer 5

Sildenafil and Nitrates

Question 6

Describe the 4 types of hypersensitivity

Answer 6

1. Exposure to an allergen causes IgE release and mast cell degranulation. Inflammation and bronchoconstriction can occur or even anaphylaxis.2. Ab mediated. Abs recognize a foreign contaminant or a drug that is similar to a tissue in our own body and our immune system attack the tissue3. Ab-Ag complexes of IgG or IgM w/ an antigen. The complexes build up in joints, kidneys etc. causing immune response.4. Contact with Ag causes delayed response and activation of CMI with Helper and cytotoxic T cells

Question 7

How can methyldopa cause an autoimmune drug toxicity?

Answer 7

Causes autoimmune reaction against Rh factor leading to hemolytic anemia

Question 8

Autoimmune reaction that occurs with administration of IV vancomycin.

Answer 8

Red Man Syndrome: rash that affects the face, neck, and upper torso. Treated with antihistamines

Question 9

Treatment for drug-induced hepatotoxicity

Answer 9

N-acetylcysteine

Question 10

Two major drug classes that are implicated in renal drug toxicity.

Answer 10

ACE-IsNSAIDs

Question 11

Describe the 3 mechanisms that drugs cause cardiotoxicity.

Answer 11

1. Potassium channel blocker leading to prolonged QT interval2. Binding iron leading to myocyte death. (Doxorubicin)3. Increasing serotonin release leading to increased cardiac valvular fibroblast proliferation and fibrosis of heart valves (Fenfluramine)

Question 12

Drugs implicated in Pulmonary toxicity.

Answer 12

Amiodarone (anti-arrhythmia), Bleomycin (chemo agent)

Question 13

Name the drug implemented in endometrial cancer.

Answer 13

Tamoxifen