Metronidazole-induced fixed drug eruption

Metronidazole Induced Cutaneous Adverse Drug Reaction- A Systematic Review of Descriptive Studies

BACKGROUND

A substantial number of research studies on metronidazole-related cutaneous symptoms have recently been published. Our objective was to identify and evaluate descriptive studies that described metronidazole-related skin manifestations, therapeutic interventions, and consequences.

METHODS

A comprehensive literature search was carried out in the PubMed, Scopus, and grey literature databases from inception to April 2022 without any constraints, as well as a snowball search in Google and a search in Google Scholar. Descriptive articles describing metronidazole-related cutaneous manifestations were considered for the review. Two distinct reviewers carried out the research selection, data extraction, and quality assessment; any discrepancies were resolved by consensus with the third reviewer.

RESULTS

About 24 out of 4648 descriptive studies, including 26 patients (20 Female patients and 6 male patients), were included in this review. The included studies comprised a range of ages from 16 to 78 years old. Metronidazole was indicated for the treatment of bacterial vaginosis, trichomoniasis, sepsis, anti-infection therapy, perforated appendicitis, rosacea, vaginal discharge, dysentery, acne rosacea, trichomonal vaginitis, lichen planus, liver abscess, facial rosacea, intestinal amoebiasis, and gingivitis. Fixed drug eruption was the most common skin manifestation which was reported in 7 cases included in this review. Cutaneous manifestations were ameliorated by cessation of the offending drug and by apportioning antihistamines, topical steroids, parenteral corticosteroids, emollients, and topical moisturizers.

CONCLUSION

Clinicians and healthcare professionals should be cognizant of the potential cutaneous adverse drug reactions (CADRs) induced by metronidazole to mitigate fatal circumstances. The management of the CADRs appears to respond effectively with immediate drug discontinuation and supportive therapy.

Immediate and Delayed Hypersensitivity Reactions to Antibiotics: Aminoglycosides, Clindamycin, Linezolid, and Metronidazole

Hypersensitivity reactions including IgE-mediated and delayed cell-mediated reactions to aminoglycosides, clindamycin, linezolid, and metronidazole are rare. For aminoglycosides, allergic contact dermatitis is the most frequent reaction for which patch testing can be a useful step in evaluation. For clindamycin, delayed maculopapular exanthems are the most common reactions. There are case reports of clindamycin associated with drug rash with eosinophilia and systemic symptoms (DRESS), acute generalized exanthematous pustulosis (AGEP), acute febrile neutrophilic dermatosis, and symmetrical drug-related intertriginous and flexural exanthema (SDRIFE). For linezolid, cases of hypersensitivity were exceedingly rare and included urticaria, angioedema, anaphylaxis, delayed rashes, and DRESS. For metronidazole, only rare cases were found across a broad spectrum of reactions including allergic contact dermatitis, fixed drug eruption, angioedema, anaphylaxis, serum sickness-like reaction, SJS/TEN, AGEP, SDRIFE, and a possible case of DRESS. IgE-mediated reactions and anaphylaxis to these types of antibiotics are uncommon, and reports of skin testing concentrations and desensitization protocols are largely limited to case reports and series. Non-irritating skin testing concentrations have been reported for gentamycin, tobramycin, and clindamycin. Published desensitization protocols for intravenous and inhaled tobramycin, oral clindamycin, intravenous linezolid, and oral and intravenous metronidazole have also been reported and are reviewed.

Drug Repurposing of the Alcohol Abuse Medication Disulfiram as an Anti-Parasitic Agent

Parasitic infections contribute significantly to worldwide morbidity and mortality. Antibiotic treatment is essential for managing patients infected with these parasites since control is otherwise challenging and there are no vaccines available for prevention. However, new antimicrobial therapies are urgently needed as significant problems exist with current treatments such as drug resistance, limited options, poor efficacy, as well as toxicity. This situation is made worse by the challenges of drug discovery and development which is costly especially for non-profitable infectious diseases, time-consuming, and risky with a high failure rate. Drug repurposing which involves finding new use for existing drugs may help to more rapidly identify therapeutic candidates while drastically cutting costs of drug research and development. In this perspective article, we discuss the importance of drug repurposing, review disulfiram pharmacology, and highlight emerging data that supports repurposing disulfiram as an anti-parasitic, exemplified by the major diarrhea-causing parasite Entamoeba histolytica.

Diagnostic workup including CD203c-based basophil activation test in immediate hypersensitivity due to metronidazole and ornidazole and evaluation of cross-reactivity in between

BACKGROUND

Little is known about the diagnostic approaches for immediate hypersensitivity reactions (IHRs) due to 5-nitroimidazole antibiotics. The aim was to evaluate the usefulness of in vivo tests and basophil activation test (BAT) for the diagnosis of IHRs due to metronidazole and ornidazole and to determine possible cross-reactivity in between.

METHODS

Forty-nine patients with a clear history of IHRs due to these drugs and 20 healthy subjects who were known to tolerate these drugs were included. Skin tests (STs) and single-blind placebo-controlled drug provocation tests (SBPCDPTs) were performed with both drugs whereas BAT was applied only with the culprit drug.

RESULTS

The most and least common reaction types were urticaria/angioedema (34.7%) and anaphylaxis (14.3%), respectively. SBPCDPTs were positive in 15 out of 47 patients, and only 7 had positive STs. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of STs for metronidazole/ornidazole were 33.3%/16.6%, 94.2%/97.3%, 60%/50%, and 84.6%/88.1%, respectively. BAT was positive in 12 out of 15 patients and negative in 10 control subjects, giving a sensitivity rate of 71.4% (CI, 29.0%-96.3%) for metronidazole and 83.3% (CI, 35.8%-99.5%) for ornidazole. The optimal concentration of both drugs for BAT was determined as 5 mg/mL. No cross-reactivity among two drugs was observed according to in vivo tests.

CONCLUSIONS

Our study showed that SBPCDPT and BAT are both useful diagnostic tools for IHRs due to 5-nitroimidazole antibiotics and can be used as supplementary to each other. No cross-reactivity between metronidazole and ornidazole in IHRs exists.

Antimicrobial Desensitization: A Review of Published Protocols

Antimicrobial desensitization represents a last-line option for patients with no alternative therapies, where the benefits of this intensive process must outweigh the potential harm from drug exposure. The goal of antimicrobial desensitization procedures is to establish a temporary state of tolerance to drugs that may otherwise cause hypersensitivity reactions. While no universal antimicrobial desensitization protocols exist, this review critically analyzes previously published desensitization protocols. The purpose of this review is to provide a greater insight for clinicians and institutions to ensure desensitization procedures are efficacious while minimizing potential for patient harm. With an increasing rate of antimicrobial resistance and the critical need to preserve antimicrobial agents, desensitization may represent another option in our antimicrobial stewardship toolkit.