Flashcards in Drug toxicity Deck (12):
1
Type I hypersensitivity rxn
Immediate hypersensitivity; results from production of IgE after exposure to an antigen
Antigen may be a foreign protein or an endogenous protein modified by a hapten to become immunogenic
2
Type II hypersensitivity rxn
Antibody-dependent cytotoxic hypersensitivity
Occurs when a drug binds to cells and is then recognized by immune system usually IgG
3
Type III hypersensitivity rxn
Immune-complex mediated hypersensitivity
Antibodies formed against soluble antigens
Antigen-antibody complex deposited in tissues initiating serum sickness (inflammatory response in tissues)
4
Type IV hypersensitivity rxn
Delayed-type hypersensitivity
Activation of cytotoxic T-cells
5
Which drugs cause autoimmune reactions?
Methyldopa- hemolytic anemia
Hydralazine, Isoniazin, Procainamide- Lupus like syndrome
6
Which drugs are reported in Stevens-Johnson syndrome (big rash that can kill you)
Reported with barbituates, sulfonamides, phenytoin, carbamazepine, allopurinal, NSAID’s, Penicillins. Mechanism not understood.
7
What is an example of the metabolite of a drug that can cause hepatotoxicity (liver damage)?
Acetaminophen (Tylenol) oxidation to N-acetyl-p-benzoquinoneimine (NAPQ-phase I,This is the toxic metabolite.).
Phase II- NAPQ conjugated. No longer toxic. With an overdose, you run out of the conjugate. Now left with this toxic metabolite. Can occur chronically or acutely. Liver damage.
8
What are some drugs implicated in renal toxicity?
NSAID’s (ibuprofin), ACEI (ace inhibitors), some antibiotics, antineoplastic agents, immunomodulators
Gentamicin- renal tubular injury reversible upon cessation
Amphotericin B- (anti-fungal) High frequency of injury because mechanism for efficacy is shared by the mechanism responsible for toxicity
Contrast-Media- Dose related nephrotoxicity
9
What are the 3 major mechanisms for cardiovascular toxicity?
1-Drug interacts with cardiac potassium channels to cause QTc prolongation, delayed repolarization, and cardiac arrythmia
2-Directly cytotoxic to myocytes
(Doxorubicin leads to production of reactive oxygen species)
3-Toxic to heart valves
10
What are the 2 drugs implicated in pulmonary toxicity?
Bleomycin
Amiodarone
11
Effects of teratogen intake at pregnancy week 3, weeks 3-8, and after organogenesis
Prior to week 3 usually result in death to embryo
Week 3-8 organogenesis occurs so very profound effects on developing organs
After organogenesis drugs may affect growth and maturation of organ but not the developmental plan
12