metronidazole
Regulatory sources consulted
Approved indications
- Infections caused by susceptible anaerobes and protozoa, including trichomoniasis, amebiasis, and giardiasis, under indication-specific regimens.
Contraindications
Absolute
- Hypersensitivity to metronidazole or nitroimidazoles; disulfiram use within the previous 2 weeks. For trichomoniasis, first trimester of pregnancy under the FDA label.
- FDA profile: Cockayne syndrome, because of the risk of irreversible and fatal acute liver failure. The CIMA profile says not to use unless no alternative exists and benefit outweighs risk.
Clinical warnings
- Major warning · It may cause encephalopathy, seizures, peripheral neuropathy, cytopenias, and SCAR; discontinue with neurologic or skin symptoms and monitor blood counts during prolonged treatment. — DailyMed, set_id 5cc3fd98-d579-432e-a4b5-b6d5586991a6
- Fulminant and fatal hepatotoxicity has been reported in Cockayne syndrome; avoid unless no alternative exists and closely monitor liver function. — DailyMed, set_id 5cc3fd98-d579-432e-a4b5-b6d5586991a6
Drug interactions
- ModerateAlcohol and propylene glycol
Mechanism: They may cause a disulfiram-like reaction.
Recommendation: Avoid during treatment and for at least 1 day afterward under CIMA; the FDA profile requires at least 3 days afterward.
DailyMed, set_id 5cc3fd98-d579-432e-a4b5-b6d5586991a6
- HighWarfarin
Mechanism: It may potentiate anticoagulant effect.
Recommendation: Monitor INR and adjust dosing.
DailyMed, set_id 5cc3fd98-d579-432e-a4b5-b6d5586991a6
- HighLithium, cyclosporine, 5-fluorouracil, or busulfan
Mechanism: Metronidazole may increase their concentrations or toxicity.
Recommendation: Avoid or monitor concentrations, renal function, and toxicity.
DailyMed, set_id 5cc3fd98-d579-432e-a4b5-b6d5586991a6
- HighPhenytoin or phenobarbital
Mechanism: Inducers may reduce metronidazole exposure; metronidazole may also reduce phenytoin clearance.
Recommendation: Monitor concentrations, antimicrobial response, and neurologic toxicity; adjust if needed.
DailyMed, set_id 5cc3fd98-d579-432e-a4b5-b6d5586991a6
- HighQT-prolonging drugs
Mechanism: They may increase the risk of QT prolongation and arrhythmia.
Recommendation: Avoid high-risk combinations or monitor ECG and electrolytes.
DailyMed, set_id 5cc3fd98-d579-432e-a4b5-b6d5586991a6
Adverse events
Common (≥1%)
Nausea, metallic taste, abdominal pain, and headache
Rare but serious
Seizures, encephalopathy, peripheral neuropathy, SCAR, and severe hepatotoxicity
Pregnancy and lactation
The FDA first-trimester contraindication is limited to trichomoniasis; for other infections, assess benefit and risk. Under the FDA profile, pump and discard milk during treatment and for 48 hours after the last dose; the CIMA profile recommends avoiding breastfeeding.
Recent literature (PubMed)
Bacterial vaginosis affects one third of reproductive-aged women, and recurrence is common. Evidence of sexual exchange of bacterial vaginosis-associated organisms between partners suggests that male-partner treatment may increase the likelihood of cure. This open-label, randomized, controlled trial involved couples in which a woman had bacterial vaginosis and was in a monogamous relationship with a male partner. In the partner-treatment group, the woman received first-line recommended antimicrobial agents and the male partner received oral and topical antimicrobial treatment (metronidazole 400-mg tablets and 2% clindamycin cream applied to penile skin, both twice daily for 7 days). In the control group, the woman received first-line treatment and the male partner received no treatment (standard care). The primary outcome was recurrence of bacterial vaginosis within 12 weeks. A total of 81 couples were assigned to the partner-treatment group, and 83 couples were assigned to the control group. The trial was stopped by the data and safety monitoring board after 150 couples had completed the 12-week follow-up period because treatment of the woman only was inferior to treatment of both the woman and her male partner. In the modified intention-to-treat population, recurrence occurred in 24 of 69 women (35%) in the partner-treatment group (recurrence rate, 1.6 per person-year; 95% confidence interval [CI], 1.1 to 2.4) and in 43 of 68 women (63%) in the control group (recurrence rate, 4.2 per person-year; 95% CI, 3.2 to 5.7), which corresponded to an absolute risk difference of -2.6 recurrences per person-year (95% CI, -4.0 to -1.2; P<0.001). Adverse events in treated men included nausea, headache, and metallic taste. The addition of combined oral and topical antimicrobial therapy for male partners to treatment of women for bacterial vaginosis resulted in a lower rate of recurrence of bacterial vaginosis within 12 weeks than standard care. (Funded by the National Health an
Rosacea is a chronic cutaneous disorder affecting primarily the face, characterized by erythema, transient or persistent, telangiectasia, and inflammatory lesions including papulo-pustules and swelling. The essential component of the disease is the persistent erythema of facial skin. Episodes of flushing (acute-subacute intermittent vasodilation) are common. Swelling and erythema of the nose along with dilatation of the pilosebaceous poral orifices, known as rhinophyma, can be noted in chronic cases. Rosacea affects up to 10% of the world population and is especially noted in fair-skinned individuals aged 35-50. Women are affected more often than men. Several treatment modalities including topical medications, systemic drugs, lasers, and light-based therapies have been used for the management of rosacea with variable results. Topical medications such as azelaic acid, metronidazole, and sulfacetamide/sulfur, oral antibiotics such as tetracyclines, and oral retinoids alone or, most commonly, in combination form the mainstay of treatment. Light therapies such as intense pulsed light and pulsed dye laser are best used for the erythemato-telangiectatic type. Topical brimonidine, oxymetazoline, ivermectin, tacrolimus, pimecrolimus, low-dose modified-release tetracyclines and botulinum toxin are the new additions to the therapeutic armamentarium. This article provides a comprehensive review of the various therapies used for rosacea.
The infection caused by Helicobacter pylori is the most common on the planet, affecting half of the global population. It is usually transmitted during childhood and persists for life if untreated. It is the primary cause of chronic gastritis, peptic ulcer, and gastric cancer. In young dyspeptic patients without alarm symptoms, the test-and-treat strategy (detection of H. pylori through a non-invasive test and subsequent eradication) is the preferred approach. The causal role of the infection in the development of gastric adenocarcinoma provides an opportunity to implement preventive strategies. The infection can be diagnosed through invasive methods (requiring endoscopy, such as the rapid urease test or histology) and non-invasive methods (such as the breath test or stool antigen test). The treatment for H. pylori combines a proton pump inhibitor with several antibiotics or bismuth salts. Benznidazole is an orally available, broad spectrum antimicrobial agent used in the treatment of Chagas disease (American trypanosomiasis). Benznidazole is a nitroimidazole similar to metronidazole and is associated with serum enzyme elevations during therapy in up to 10% of patients but has not linked to cases of clinically apparent acute liver injury.
Acne is one of the most common dermatological conditions to affect women of childbearing age, so it is important to consider the safety of long-term acne treatments on women who could become pregnant. In this review article, we clarify what management options are available to treat acne during pregnancy. Topical treatments, typically first-line for acne, such as azelaic acid, clindamycin, erythromycin, metronidazole, benzoyl peroxide, salicylic acid, dapsone, and retinoids, were reviewed. Systemic treatments, such as zinc supplements, cephalexin, cefadroxil, amoxicillin, azithromycin, erythromycin, and corticosteroids, typically second-line for acne, were also reviewed. Alternative treatments such as light therapy and cosmetic procedures were also evaluated. Due to recommendation of sunscreen utilization during acne treatments, sunscreen usage during pregnancy was also assessed. Management of acne during unplanned pregnancy was discussed in further detail regarding safety and adverse effects. Through summarized tables and examples of studies demonstrating safety and efficacy of treatments, the following is a resource for providers and patients to utilize for management of acne during pregnancy.