Metronidazole, adverse drug reaction

Toxicity Adverse effects of metronidazole include gastrointestinal irritation, headache, and dark coloration of urine. More serious toxicity includes leukopenia, dizziness, and ataxia. Drug interactions with metronidazole include a disulfiram-like reaction with ethanol and potentiation of coumarin anticoagulant effects. Safety of metronidazole in pregnancy and in nursing mothers has not been established. 

Educating the Patient and Family Anytime a drug is prescribed for a patient, the nurse is responsible to ensure that the patient has a thorough understanding of the drug, the treatment regimen, and the potential adverse reactions. Not all of the miscellaneous anti-infectives are prescribed for use within the clinical setting. Chloramphenicol, metronidazole, and... 

Emetine, once the drug of choice for the treatment of amebiasis, despite marked cardiotoxicity, has largely been replaced by metronidazole and related compounds for this indication. Large doses of emetine can damage the heart, hver, kidneys, intestinal tract, and skeletal muscle. Allergic reactions and tumor-inducing effects have not been described. Dehydroemetine is a httle less toxic but also less effective than emetine its adverse effects are similar (SED-11, 594). 

Drug intolerance often limits the usefulness of agents used to treat IBD. Many patients receiving sulfasalazine, mesalamine, corticosteroids, metronidazole, azathioprine, mercaptopurine, or infliximab experience some undesired effects. In some cases, these adverse effects can be significant and require discontinuation of the therapy. Knowledge of the common or important adverse reactions will assist in avoiding or minimizing their effects. 

The authors of the report attribute the dystonia to an interaction between metronidazole and chloroquine as she had taken both drugs alone without adverse effect. However, they do not fiilly assess the possible contribution of promethazine, which is known to cause dystonias. It is therefore possible that the reaction seen was an adverse effect of the promethazine, or perhaps even an interaction between promethazine and chloroquine. No general recommendations can therefore be made from this single report. 

Systematic reviews It is estimated that 40-50 million people worldwide who are infected with Entameba histolytica develop amebic colitis, resulting in up to 100 000 deaths per year. Metronidazole is the drug of choice and is often given in combination with other drugs in order to eliminate the parasites. However, there is insufficient evidence to support combination therapy, while the occurrence of adverse reactions to metronidazole and the possibility of parasite resistance are other concerns. 

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