metronidazole
Regulatory sources consulted
Approved indications
- Trichomonas urethritis and vaginitis.
Contraindications
Absolute
- Hypersensitivity to metronidazole, other imidazoles, or excipients.
Clinical warnings
- Major warning · For prolonged treatment, monitor blood counts and neurologic symptoms; stop and assess if paresthesia, ataxia, vertigo, or seizures occur. Use cautiously in hepatic encephalopathy or severe neurologic disease. — CIMA/AEMPS, ficha técnica 34985
- Vaginal tablets may weaken latex condoms or diaphragms. — CIMA/AEMPS, ficha técnica 34985
- Major warning · Severe irreversible hepatotoxicity and rapidly developing acute liver failure, including fatal outcomes, have been reported with systemic metronidazole in people with Cockayne syndrome. Do not use unless benefit outweighs risk and no alternative is available; monitor liver function before, during, and after treatment, and stop for marked elevation or symptoms of liver injury. — CIMA/AEMPS, ficha técnica 34985
- Major warning · Potentially life-threatening severe cutaneous adverse reactions have been reported, including Stevens-Johnson syndrome, toxic epidermal necrolysis, and acute generalized exanthematous pustulosis. Stop metronidazole immediately if compatible signs or symptoms occur. — CIMA/AEMPS, ficha técnica 34985
Drug interactions
- HighAlcohol and alcohol-containing medicines
Mechanism: A disulfiram-like reaction may occur.
Recommendation: Avoid during treatment and for at least 24 hours afterward.
CIMA/AEMPS, ficha técnica 34985https://cima.aemps.es/cima/dochtml/ft/34985/FT_34985.html
- HighWarfarin and other coumarin anticoagulants
Mechanism: Metronidazole may enhance anticoagulation and increase bleeding risk.
Recommendation: Monitor INR or prothrombin time and adjust the anticoagulant.
CIMA/AEMPS, ficha técnica 34985https://cima.aemps.es/cima/dochtml/ft/34985/FT_34985.html
- HighDisulfiram
Mechanism: Concomitant administration has been associated with psychotic reactions.
Recommendation: Do not administer metronidazole to people who have taken disulfiram within the previous two weeks.
CIMA/AEMPS, ficha técnica 34985https://cima.aemps.es/cima/dochtml/ft/34985/FT_34985.html
- HighBusulfan
Mechanism: Metronidazole may increase busulfan plasma concentrations and cause serious toxicity.
Recommendation: Avoid concomitant administration unless benefit outweighs risk; if essential, frequently monitor busulfan concentrations and adjust its dose.
CIMA/AEMPS, ficha técnica 34985https://cima.aemps.es/cima/dochtml/ft/34985/FT_34985.html
- HighQT-prolonging medicines
Mechanism: QT prolongation has been reported, particularly when metronidazole is given with other medicines capable of prolonging QT.
Recommendation: Assess risk before combining; the product information notes reports of QT prolongation with this combination.
CIMA/AEMPS, ficha técnica 34985https://cima.aemps.es/cima/dochtml/ft/34985/FT_34985.html
- HighLithium
Mechanism: Metronidazole may increase lithium plasma concentrations and cause toxicity.
Recommendation: Monitor serum lithium, creatinine, and electrolytes during concomitant administration.
CIMA/AEMPS, ficha técnica 34985https://cima.aemps.es/cima/dochtml/ft/34985/FT_34985.html
- HighCyclosporine
Mechanism: Metronidazole may increase cyclosporine plasma concentrations.
Recommendation: If concomitant administration is necessary, closely monitor cyclosporine concentrations and creatinine.
CIMA/AEMPS, ficha técnica 34985https://cima.aemps.es/cima/dochtml/ft/34985/FT_34985.html
- ModeratePhenytoin or phenobarbital
Mechanism: They may increase metronidazole elimination and reduce its plasma concentrations.
Recommendation: Monitor the clinical response to metronidazole and its concentrations when available during concomitant administration.
CIMA/AEMPS, ficha técnica 34985https://cima.aemps.es/cima/dochtml/ft/34985/FT_34985.html
- High5-fluorouracil
Mechanism: Metronidazole may reduce 5-fluorouracil clearance and increase its toxicity.
Recommendation: If the combination is necessary, closely monitor 5-fluorouracil toxicity and review its treatment with the responsible team.
CIMA/AEMPS, ficha técnica 34985https://cima.aemps.es/cima/dochtml/ft/34985/FT_34985.html
Adverse events
Rare but serious
Angioedema or anaphylactic shock · Agranulocytosis, neutropenia, or thrombocytopenia
Pregnancy and lactation
Carefully weigh benefit and risk during pregnancy. Avoid unnecessary use while breastfeeding because metronidazole passes into milk.
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.