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SIDE EFFECTS AND TOXICITY. 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.
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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.
CLINDAMYCIN • Diarrhea fairly common
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.
ANAPHYLAXIS • Careful observation of the patient is important.
ANAPHYLAXIS-TREATMENT • Epinephrine (IV or IM) • IV steroids • Supportive measures
MGMT. OF THE PATIENT POTENTIALLY ALLERGIC • Evaluation and history.
www.bris.ac.uk/ Depts/ ENT
CEPHALOSPORINS • Rashes occur frequently. • Cross-sensitivity to penicillins.
HYPERSENSITIVITY REACTIONS • Patients with a history of a mild or temporally distant reactionto penicillin appear to be at low risk.
Sulfonamides • Skin rashes are common.
STEVENS JOHNSON SYNDROME • Uncommon but most likely to occur following sulfonamide therapy
PHOTOSENSITIVITY • Sulfonamides • Tetracyclines • Fluoroquinolones
HEMATOLOGICAL TOXICITY • Sulfonamides (with trimethoprim) • Chloramphenicol • Ticarcillin and Piperacillin • Linezolid
TRIMETHOPRIM DNA FOLINICACID DIHYDROPTEROIC ACID Dihydropteroate Synthetase DHF Dihydrofolate Reductase THF
CHLORAMPHENICOL • HEMATOLOGICAL TOXICITY-2 TYPES
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.
TICARCILLIN AND PIPERACILLIN • Prolong bleeding time (by altering platelet function).
LINEZOLID` • Myelosuppression (anemia, thrombocytopenia, leukopenia)
HEPATOTOXICITY • Erythromycin estolate (cholestatic hepatitis) • Tetracyclines
CHOLESTATIC HEPATITIS • It is caused primarily by the estolate. • Not dose-related. • It is probably a hypersensitivity reaction (to estolate ester).
TETRACYCLINES • Dose-related hepatotoxicity (pregnancy).
NEUROLOGICAL EFFECTS • Imipenem (seizures) • Aminoglycosides • Fluoroquinolones • Metronidazole
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.
Amino Glycosides
FLUOROQUINOLONES • CNS effects such as headache, restlessness, and dizziness. High doses may produce convulsions.
METRONIDAZOLE • Headache, dizziness, peripheral neuropathy.
CARDIOVASCULAR EFFECTS • Fluoroquinolones • Erythromycin • Chloramphenicol
FLUOROQUINOLONES • Some 3rd and 4th generation FQ’s can prolong the QT interval.