side effects and toxicity. gi effects almost all antibiotics are irritating to the gi tract....
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GI EFFECTS
Almost all antibiotics are irritating to the GI tract.
Diarrhea is very common.
Nausea, vomiting.
TETRACYCLINES-GI EFFECTS
Common upon oral administration.
Epigastric burning and distress, abdominal discomfort, nausea and vomiting and diarrhea.
ADVERSE EFFECTS
Nausea and vomiting usually subside as medication continues.
If troublesome GI irritation can be controlled with food.
Important to distinguish irritative diarrhea from superinfection.
HYPERSENSITIVITY REACTIONS
Most antibiotics produce hypersensitivity reactions.
β-lactams.
Sulfonamides and its combinations.
PENICILLINS
Cross allergenicity among all the penicillins (and other beta lactams).
Results from a previous treatment.
HYPERSENSITIVITY REACTIONS
Occurs with almost any dosage form of penicillin. Oral penicillins have a lower risk than parenterals.
Usually clear with elimination of the penicillin.
HYPERSENSITIVITY REACTIONS Skin rashes.
Fever.
Bronchospasm.
Vasculitis, serum sickness, exfoliative dermatitis, contact sensitivity, local swelling and redness,oral lesions, eosinophilia.
ANGIOEDEMA AND ANAPHYLAXIS.
ANAPHYLAXIS
Most important immediate danger.
Incidence is low (0.04 -0.2%).
Sudden, severe hypotension and rapid death.
www.bris.ac.uk/Depts/ ENT
HYPERSENSITIVITY REACTIONS
Patients with a history of a mild or temporally distant reaction to penicillin appear to be at low risk.
HEMATOLOGICAL TOXICITY
Sulfonamides (with trimethoprim)
Chloramphenicol
Ticarcillin and Piperacillin
Linezolid
DIHYDROPTEROIC ACID
TRIMETHOPRIMDihydrofolate Reductase
Dihydropteroate Synthetase
DHF
THF
DNAFOLINIC ACID
IDIOSYNCRATIC APLASTIC ANEMIA
Leukopenia, thrombocytopenia, and aplasia of the marrow.
Not dose-related.
Can be fatal.
DOSE-DEPENDENT ANEMIA
Reversible dose-related suppression of bone marrow.
Usually presents as anemia, reticulocytopenia and increased serum iron.
Associated with high doses and/or prolonged treatment.
Results from inhibition of mitochondrial protein synthesis.
CHOLESTATIC HEPATITIS
It is caused primarily by the estolate.
Not dose-related.
It is probably a hypersensitivity reaction (to estolate ester).
NEUROMUSCULAR BLOCKADE Rare but potentially serious.
Occurs at high concentrations of aminoglycosides or in patients with an underlying risk factor.
Acute neuromuscular blockade, respiratory paralysis and death can occur.
ACh ACh
ACh
ACh
AChACh
ACh
Ac + Ch
cholineacetyltransferase
high affinityuptake
vesicle
receptorACh esterase
ACh
tdh
AcetylCoA + ChTD
H 7/
90
AminoGlycosides
FLUOROQUINOLONES
CNS effects such as headache, restlessness, and dizziness. High doses may produce convulsions.
GRAY BABY SYNDROME
Neonates, especially premature babies.
Abdominal distention, vomiting, circulatory collapse, ashen or pallid cyanosis.
Inadequate glucuronidation in the newborn.
AMINOGLYCOSIDES
Accumulate in the renal cortex (mainly proximal tubules).
Reversible and usually mild.
Reduced excretion can lead to ototoxicity.
OTOTOXICITY
The most serious toxic effect (uncommon, irreversible and cumulative).
Caused by all the aminoglycosides.
OTOTOXICITY
Both auditory and vestibular dysfunction can occur.
Results from destruction of sensory hair cells.
RED NECK OR RED MAN SYNDROME
Rapid IV infusion of vancomycin may cause erythematous or urticarial reactions, flushing, tachycardia and hypotension.
Due to a direct toxic effect on mast cells (with histamine release).
SUPERINFECTIONS Broad spectrum penicillins and
cephalosporins.
Chloramphenicol
Tetracyclines
Clindamycin
AAPC
Characterized by watery diarrhea, abdominal pain, fever, blood and mucus in stools. It can be fatal.