Sutrol

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Medically reviewed

Laura Arias

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Sutrol

Quick Facts: Sutrol

Property Description
Active ingredient Metronidazole
Form Tablets, oral suspension, intravenous solution, topical preparation, and vaginal suppositories
Pharmacological class Antimicrobial agent, specifically an antibiotic and antiprotozoal agent
Common use Systemic or local elimination of anaerobic bacteria and protozoa
Origin Synthetic, belonging to the nitroimidazole derivative family

What Type of Medicine is Sutrol, and What Does it Contain?

Sutrol is the commercial designation for a prescription-only medication whose active ingredient is Metronidazole. It is classified as an antimicrobial agent, recognized for both its antibiotic and antiprotozoal properties. Metronidazole is a synthetic compound belonging to the nitroimidazole derivative family. This focused classification distinguishes its use, as it is clinically recognized for its efficacy against infections caused by oxygen-sensitive organisms, a distinction that sets it apart from common broad-spectrum antibiotics.


Available Forms of Sutrol and General Purpose

The medication is available in several pharmaceutical preparations, including common tablets for oral use, intravenous solution for systemic administration, and specialized topical preparation and vaginal suppositories. This variety of dosage forms ensures that Metronidazole can be delivered effectively through the most appropriate route of administration. The compound’s inclusion on the World Health Organization's Model List of Essential Medicines underscores its significance as a globally important antimicrobial agent. The primary general purpose of this agent is to address a typical use scenario: combating infections caused by microorganisms that thrive in low-oxygen settings, such as anaerobic bacteria and specific types of protozoa, helping the body resolve infections where these particular pathogens are confirmed as the cause.


How is Sutrol's Action Unique?

The potency of Metronidazole stems from its highly selective mechanism of effect, which is uniquely triggered only within its target organisms. The compound must be chemically reduced inside the anaerobic bacteria and protozoa to become fully active, a property that makes its targeting specific. Once activated, the compound exerts a powerful bactericidal or antiparasitic action by damaging the organism’s DNA and nucleic acid synthesis. This targeted action provides a concentrated therapeutic benefit targeting these oxygen-sensitive pathogens.

Regulatory References

  1. Metronidazole Drug Information (NIH)
  2. Metronidazole Dosage Forms (NIH)

What side effects are possible with Sutrol?

Sutrol is an extended-release antiemetic injection. The safety profile, documented in official labeling, is primarily defined by Injection Site Reactions (ISRs) and specific systemic risks.

Common Side Effects

The most frequently reported adverse reactions (ge 3%) include:

  • Injection site reactions (such as pain, tenderness, bruising, or swelling)
  • Constipation, diarrhea, abdominal pain, dyspepsia, and gastroesophageal reflux
  • Fatigue, headache, dizziness, insomnia, and asthenia (lack of strength)

Injection site reactions, including pain or tenderness, are particularly common, with some reactions possibly appearing two weeks or more after administration. Bruising or hematoma formation at the injection site may be more likely in patients concurrently receiving antiplatelet agents or anticoagulants.

Serious and Clinically Significant Adverse Reactions

Serious safety concerns documented in regulatory sources include:

  • Gastrointestinal Disorders: Decreased bowel activity and severe constipation are noted risks. Patients with risk factors for gastrointestinal obstruction should be monitored, and immediate medical care is advised if signs of ileus occur.
  • Hypersensitivity Reactions: Serious allergic reactions have been reported. These may have a delayed onset, occurring up to seven days or longer after the injection, and may follow an extended course.
  • Serotonin Syndrome: This has been reported with 5-HT3 receptor antagonists, especially when used simultaneously with other serotonergic medicines.

Restrictions and Specific Population Safety

Sutrol is contraindicated in patients with a known hypersensitivity to the drug substance, its components, or any other 5-HT3 receptor antagonist. It must not be administered into areas of the skin that are burned, hardened, inflamed, swollen, or otherwise compromised. Use in patients with severe renal impairment (CrCl < 30 mL/min) should be avoided. In patients with moderate renal impairment (CrCl 30-59 mL/min), administration must be restricted to no more frequently than once every 14 days.

Overdose and Emergency Response

Sutrol Overdose and when to seek help

The official regulatory documents for Sutrol (Metronidazole) outline the documented manifestations and required clinical actions in the event of overexposure. The established overdose profile is structured around the two main physiological systems affected: the gastrointestinal system and the central nervous system.


Documented Manifestations and Severe Outcomes

Reported cases of massive single oral doses are associated with nausea, vomiting, and ataxia (impaired coordination). More critical symptoms, classified as neurotoxic effects, include the documented potential for seizures and peripheral neuropathy. These severe outcomes have been observed following high-dose, prolonged exposure regimens. The appearance of any abnormal neurological signs or symptoms necessitates immediate medical attention and prompt clinical evaluation.


Required Clinical Actions

The regulatory labeling explicitly states that there is no specific antidote known for Metronidazole overdose. Therefore, management must consist exclusively of symptomatic and supportive therapy. For patients with end-stage renal disease or hepatic impairment, monitoring for metronidazole-associated adverse events is required due to the risk of metabolite accumulation, a key consideration in overdose scenarios.

Therapeutic Uses of Sutrol

What Sutrol Treats: Main Uses and Benefits

Sutrol is used across therapeutic domains where additional symptomatic support is needed, generally applied in situations involving certain distressing symptoms linked to anaerobic bacteria and certain protozoa (parasites). The medication is applied in clinical settings that involve acute or disruptive symptom patterns. It is relevant for easing symptoms related to inflammatory or irritative states in conditions such as intra-abdominal abscesses, septicemia, Clostridium difficile colitis, Amebiasis, Giardiasis, and certain genitourinary infections including trichomoniasis and bacterial vaginosis.

In these contexts, the primary therapeutic benefit is aligned with domains involving significant symptom expression, which supports the management of the overall symptom burden. Use is often relevant when symptoms become temporarily overwhelming, assisting with the management of intense manifestations like high fever, persistent diarrhea, or abnormal discharge and odor.

“The intent of this therapy is relevant for easing challenging symptoms, offering symptomatic relief that may help patients cope more steadily with difficult episodes.”


Quick Fact: Support for Symptomatic Discomfort
Symptom Domain Conditions Addressed
Gastrointestinal Distress Amebiasis, Giardiasis, C. difficile Colitis
Systemic/Deep-Tissue Intra-abdominal abscesses, Septicemia, Aspiration Pneumonia
Genitourinary Symptoms Trichomoniasis, Bacterial Vaginosis

Regulatory References

  1. NIH DailyMed official drug information

Eligibility and Restrictions for Use

Who Can and Cannot Use Sutrol?

Eligibility to use Sutrol (Metronidazole) is strictly governed by population-specific restrictions and mandatory contraindications outlined in official regulatory documents.

Contraindicated Populations (Must Not Use)

Contraindication Basis of Restriction
Hypersensitivity Prior history of allergy to metronidazole or other nitroimidazole derivatives
Recent Disulfiram Use Taken disulfiram within the last two weeks
Alcohol/Propylene Glycol Consumption of alcohol or products containing propylene glycol during treatment and for a specified post-treatment period
Cockayne Syndrome Risk of severe, irreversible hepatotoxicity and acute liver failure

Restricted or Conditional Use

Use of Sutrol requires caution and potential adjustment in several population groups:

  • Severe Hepatic Impairment: Patients with severe liver impairment (e.g., Child-Pugh C) typically require a reduced dose due to altered drug metabolism.
  • Central Nervous System (CNS) Disease: Use is conditional for patients with active organic CNS disease or a history of blood dyscrasias.
  • Pregnancy and Lactation: Use in the first trimester of pregnancy is often not recommended. During lactation, a temporary interruption of breastfeeding is usually advised following high single-dose regimens.
  • Pediatric Use: Safety and efficacy are not established for some formulations in the general pediatric population, although use is permitted for specific, approved indications like amebiasis.

What should I know about interactions with other medicines?

Sutrol Interactions with other medicines and products

The official regulatory profile of Sutrol (Metronidazole) identifies substances that are strictly prohibited for co-administration and those that significantly alter drug exposure or effects, as documented in government sources.

Interaction Scope Description / Examples
Medicinal products with documented interactions Warfarin, Disulfiram, Lithium, Busulfan, Phenytoin, Phenobarbital, Cimetidine.
Population-specific interaction notes Clearance is significantly reduced in severe hepatic impairment, leading to markedly increased plasma exposure of Sutrol.
Timing-based interaction rules Disulfiram must not have been taken within the last two weeks; Alcohol and Propylene Glycol must be avoided during and for at least three days after therapy.

Interaction Classifications (Regulatory Basis):

  • Contraindicated Combinations: Disulfiram; Alcoholic Beverages and Propylene Glycol-containing products are strictly prohibited.
  • Exposure-Modifying Substances: Agents that inhibit ( Cimetidine) or induce ( Phenytoin) certain metabolic enzymes may increase or decrease Sutrol plasma concentrations, respectively.
  • Pharmacodynamic Interaction: Sutrol potentiates the anticoagulant effect of Warfarin and other oral coumarin derivatives.

Official Interaction Statements (Summary):

Co-administration is contraindicated with Disulfiram taken in the preceding two weeks, and with alcohol or propylene glycol-containing products due to the risk of severe reactions. Sutrol alters the effects of anticoagulants like Warfarin, leading to a prolongation of prothrombin time. Exposure is significantly affected by liver function, as severe hepatic impairment increases the product’s plasma concentrations.

Mechanism of Action

The mechanism of Sutrol (Metronidazole) is defined by its selective toxicity against specific microorganisms that thrive in low-oxygen environments. Its action is strictly confined to the biological processes of these susceptible pathogens.

Activation within Anaerobic Environments

The drug functions as an inactive prodrug that must undergo chemical reduction to become effective. It exploits the unique low-redox potential of electron-transport proteins (like ferredoxin) found only in anaerobic bacteria and protozoa, which facilitate the chemical reduction of the drug's nitro group into a highly reactive substance. The selective activation ensures the damaging effect is primarily limited to the target microorganisms by exploiting the anaerobic environment, defining its scope of action.

Targeted DNA Fragmentation

The activated form of Metronidazole generates unstable radical intermediates that are the cytotoxic species responsible for the drug's effect. These radicals directly and irreversibly attack the microbial DNA and other nucleic acids, causing extensive strand breaks and covalent binding. This profound molecular damage rapidly inhibits DNA synthesis and repair, leading to a bactericidal or antiparasitic physiological consequence.

Constraints of the Low-Oxygen Mechanism

The efficacy of the drug's mechanism is physiologically constrained by the local oxygen tension. In high-oxygen environments, the toxic activation fails because oxygen competes for the necessary electron, rendering the drug inert (futile cycling). The mechanism is also limited if the target organism develops acquired resistance, such as by altering the microbial enzymes (nitroreductases) required to initiate the drug's activation process.

Dosage and Administration Information

How to Use Sutrol: Official Administration Guidelines

The usage of Sutrol (Metronidazole) is defined by clinical protocols which establish the framework for its delivery and schedule. The medicine is administered through several established routes, with specific dosing regimens tailored to the formulation being used.


Administration Scope

Feature Instruction
Route of Administration Oral, Intravenous (IV) infusion, Topical, and Vaginal
Dosing Schedule (Adults) For systemic infections, an IV loading dose of 15 mg/kg is typically followed by a maintenance dose of 7.5 mg/kg (IV or oral) every 6 hours (q6hr). A maximum daily dose of 4 g is the established limit
Timing in relation to meals Immediate-release (IR) forms may be taken with food. Extended-release (ER) tablets must be taken on an empty stomach (1 hour before or 2 hours after meals)
Preparation requirements IV solutions require infusion over 30 to 60 minutes. Oral suspensions must be shaken well before measurement
Special procedural conditions A 50% dose reduction is required for patients with severe hepatic impairment. Dose adjustment is generally not required for renal impairment, but a supplementary dose may be considered after hemodialysis

Instruction Classifications

Classification Pattern
Administration method type Systemic (Oral/IV) and Local (Topical/Vaginal)
Frequency pattern Fixed interval (q6hr, TID) or Fixed daily (qDay)
Course duration Typically 7 to 10 days for systemic and amoebic infections

Connection to the overall use protocol

The official administration guidelines establish a protocol that mandates the delivery method, numerical dosage, frequency, and duration for using Sutrol. This structure ensures that the use of the medicine is standardized across clinical practice, tying the physical administration to the conditions documented for the compound. The explicit instructions for dose adjustments and procedural conditions define the standard parameters for use across different patient profiles.

Recent Clinical Evidence

Research evidence / Overview of studies for Sutrol (Metronidazole)


Evidence for Use in Bacterial Vaginosis and Trichomoniasis

Numerous Randomized Controlled Trials (RCTs) were conducted to study Sutrol for Bacterial Vaginosis and Trichomoniasis, which are conditions characterized by fluctuating or episodic manifestations. These studies primarily focused on short-term outcomes, using study designs to compare Sutrol (in both oral and topical forms) against a placebo or other active treatments. Research examined outcomes related to physical discomfort and systemic or functional imbalance by measuring specific endpoints, such as clinical cure (an endpoint measuring symptom change) and the eradication of the target organisms or parasites.

For both conditions, findings describe patterns observed in the studies where an observed portion of the populations reported measurements of organism clearance (eradication endpoint) in the short term. For Trichomoniasis, studies monitored the clearance of the parasite across various dosing schedules, with comparative trials exploring the outcomes of different treatment course lengths. For Bacterial Vaginosis, studies reported measurements of clinical cure using established diagnostic criteria.


Evidence for Use in Amebiasis and Giardiasis

Sutrol was evaluated in research for parasitic infections, specifically Amebiasis and Giardiasis, which are conditions associated with acute or disruptive episodes of gastrointestinal distress. The evidence supporting its use largely comes from clinical trials and observational studies, where research examined outcomes reflecting daily functioning or activity level. Studies primarily focused on measuring parasite eradication and monitoring changes in acute symptoms (such as diarrhea and abdominal pain) during the study period.

For Amebiasis, Sutrol was often evaluated as part of a combination regimen, meaning the contribution of Sutrol alone to the measured symptom patterns is difficult to isolate from the other medications studied. For Giardiasis, studies of short courses reported measurements of parasite clearance and symptom measurement shifts in the observed populations.


Evidence for Use in Anaerobic and C. difficile Infections

For serious anaerobic bacterial infections (such as intra-abdominal abscesses), Sutrol was primarily evaluated in Randomized Controlled Trials (RCTs) as part of a combination regimen designed to address anaerobic pathogens. These studies monitored physiological strain or stress, examining outcomes related to systemic or functional imbalance, such as survival/mortality rates, the need for additional procedures, and clinical response (e.g., resolution of fever). Sutrol was evaluated in research for Clostridioides difficile colitis, where comparative research suggests findings were mixed, particularly concerning recurrence measurements.


What Research Gaps and Uncertainties Remain

The existing research base, while substantial, includes several key limitations. Follow-up durations were limited in many of the trials conducted for Sutrol’s uses, leading to limited information for long-term outcomes that track sustained symptom patterns and response over time. Comparative evidence is lacking against some newer drug options for several infections. Furthermore, research does not determine Sutrol's effect as a single agent versus its role in a combination regimen for serious anaerobic infections.

Key Studies & References

  1. Comparative Effectiveness of Treatments for Bacterial Vaginosis: A Network Meta-Analysis (Sources for cure rates, short-term outcomes, and recurrence in Bacterial Vaginosis)
  2. Metronidazole - Wikipedia (General overview of medical uses, including Amoebiasis, Giardiasis, and C. difficile)
  3. Complicated intra-abdominal infections: ceftolozane/ tazobactam | NICE (Source for Metronidazole use as part of combination regimens for anaerobic/intra-abdominal infections in RCTs)
  4. ACG Clinical Guidelines: Prevention, Diagnosis, and Treatment of Clostridioides difficile Infections (Source for C. difficile colitis treatment and recurrence data)

Frequently Asked Questions (FAQ)

Common questions about Sutrol (FAQ)


Q: Is Sutrol the same kind of medicine as [similar drug name]?

A: Sutrol contains the active ingredient metronidazole, which is classified by regulatory authorities as a nitroimidazole derivative. This places it in a category of medicines used as an antibiotic and antiprotozoal agent specifically against certain types of bacteria and parasites.


Q: What are the most commonly reported side effects of Sutrol?

A: According to official product information, commonly reported adverse effects in clinical trials include issues like nausea, vomiting, diarrhea, headache, loss of appetite, and a metallic taste in the mouth. These effects are included in the known safety profile described in official documentation.


Q: How long does it usually take for Sutrol to start working?

A: The time it takes for Sutrol to take effect is related to its pharmacological duration. The average elimination half-life of metronidazole in healthy subjects is approximately eight hours. While this determines its fixed dosing schedule, initial changes in symptoms are typically observed within a few days, according to patient information.


Q: Can Sutrol be taken by people who have [common chronic condition, e.g., high blood pressure]?

A: Official documentation for Sutrol's active ingredient does not typically cite common chronic conditions like high blood pressure as a specific restriction or contraindication for use. The disclosure of all medical conditions to a healthcare provider is a standard part of initiating treatment.


Q: Is it normal to feel a little [mild, non-serious side effect, e.g., drowsy/lightheaded] when starting Sutrol?

A: Official product information lists common effects such as dizziness, headache, fatigue, and asthenia (lack of strength). Experiencing these feelings may be within the known scope of effects when initiating treatment.


Q: Are there any common over-the-counter (OTC) pain relievers that interact with Sutrol?

A: Official guidance requires patients to inform their healthcare provider about all medications and supplements, including over-the-counter pain relievers, to review for potential drug interactions. This practice helps facilitate the review of potential co-administration risks.


Q: What is the risk of having a serious side effect from Sutrol?

A: Official documents list serious, clinically significant adverse reactions, such as convulsive seizures, peripheral neuropathy, and serious hypersensitivity reactions (severe allergic reactions). The occurrence of these effects is described as being monitored closely during the medication's use.


Q: What should I know about Sutrol's safety classification?

A: Metronidazole has been assigned an FDA Pregnancy Category B, which reflects data on its use during pregnancy. Additionally, certain oral formulations carry the most serious warning (Boxed Warning) regarding carcinogenic findings (potential to cause cancer) observed in animal studies.


Q: What is the risk of interactions between Sutrol and anti-depressants?

A: Official product information notes that interactions can exist between metronidazole and certain classes of medicines that affect the central nervous system (CNS), including some antidepressants. Any co-administration with these types of medicines is subject to ongoing monitoring by a healthcare professional, as described in regulatory guidelines.


Q: Can I use Sutrol if I have diabetes?

A: Official product information does not commonly cite diabetes as a restriction or contraindication for use. Evaluation of a patient's overall treatment plan by a healthcare provider remains a necessary step prior to use.


Q: Is it true that Sutrol should not be crushed or split?

A: Extended-release (ER) tablets are designed to release the medication slowly over time. Official instructions state they must not be crushed, chewed, or broken to prevent an increased risk of side effects from rapid drug release.


Q: Does Sutrol have a warning about driving or operating machinery?

A: Regulatory information notes that metronidazole has been associated with neuropsychiatric adverse reactions, including symptoms like confusion or dizziness. These effects may impair physical or mental abilities, requiring caution when performing such tasks.


Q: Can Sutrol be used by older adults (e.g., people over 65)?

A: Use in geriatric patients is generally permitted. However, official guidance recommends monitoring for metronidazole-associated adverse events in this population, as a higher concentration of the active metabolite may be present.


Q: Why do some people need to take Sutrol for a long period of time?

A: While typical courses for metronidazole are short, longer courses of treatment may be required for specific, serious infections. Examples include those involving the bone, joints, lower respiratory tract, and the lining of the heart (endocardium).


Q: How long does the effect of one dose of Sutrol typically last?

A: The average elimination half-life of metronidazole in healthy individuals is approximately eight hours. This pharmacological measure helps determine the required interval between doses for maintaining consistent levels of the medication.


Q: Is there a reason why Sutrol must be taken at a specific time of day?

A: The reason for strict timing relates to maintaining consistent drug levels in the body. The required dosing frequency, often every six hours (q6hr) for systemic infections, establishes a fixed administration schedule that should be maintained consistently throughout the day.


Q: Is there a maximum daily limit for taking Sutrol?

A: For the treatment of anaerobic bacterial infections, the official label cites a maximum daily dose of 4 grams (4 g) over a 24-hour period. This limit is established to prevent excessive systemic exposure to the drug.


Q: Does Sutrol have an effect on a person's mood or energy levels?

A: Official documentation notes potential adverse effects on the central nervous system, which can affect energy. These include common issues like fatigue and asthenia (lack of strength), and less commonly, changes in mental state such as confusion or depression.


Q: Is the list of side effects in the patient leaflet complete, or are there others?

A: Official labeling is required to include the most frequently observed and clinically significant adverse reactions. However, documentation also notes that additional adverse events may be reported during the drug's ongoing post-marketing experience.


Q: Is it possible to take too much Sutrol by accident?

A: In cases of excessive exposure, official prescribing information notes that there is no specific antidote for metronidazole overdose. Management of such an event is documented as involving providing supportive and symptomatic treatment.


Q: What evidence exists regarding Sutrol's use in children?

A: Safety and efficacy are not established for all formulations in the general pediatric population. However, some specific uses, such as for amebiasis, are permitted with dosage adjustments based on body weight and other factors.


Q: What are the typical expected outcomes when a person is using Sutrol?

A: Outcomes are measured in clinical research based on the specific infection being treated. Expected outcomes are documented as clinical cure (meaning a change or reduction in symptoms) and organism eradication.


Q: Does Sutrol have an expiration date, and is it important to follow it?

A: As with all prescription medicines, Sutrol products have a manufacturer-determined expiration date. Following the date is necessary to ensure the product retains its documented strength and purity.


Q: What is the purpose of the 'black box warning' mentioned in some documents for Sutrol?

A: The most serious warning (Boxed Warning) is required by the FDA for certain oral formulations due to the drug demonstrating carcinogenic findings (potential to cause cancer) in animal studies. This is a standard warning based on regulatory findings.


Q: Can Sutrol be taken with antacids?

A: Use with certain acid-reducing medications (such as H2 receptor blockers and some antacids) has been noted as a potential interaction that may require monitoring. Disclosure of the use of these products to a healthcare provider is a required step for initiating treatment.


Q: Is Sutrol safe for someone with a history of seizures/epilepsy?

A: Official documentation notes that metronidazole should be administered with caution in patients with a history of Central Nervous System (CNS) disease. This is due to regulatory reports of convulsive seizures and other neurological disturbances.


Q: Are there any lab tests required while taking Sutrol?

A: Monitoring of total and differential leukocyte counts (a type of blood test) is recommended before and after prolonged or repeated courses of therapy. This monitoring is documented as being recommended for potential effects on blood components.


Q: Can I take other prescription medications at the same time as Sutrol?

A: Metronidazole is known to interact with several specific prescription medications. Patients should always review all co-administered prescription medications with their healthcare provider for potential drug interactions.


Q: Is Sutrol safe to take with common vitamins like Vitamin D or a multivitamin?

A: Official guidance advises patients to inform their healthcare provider about all vitamins, supplements, and herbal products they are taking. This general practice facilitates the review of all co-administered substances, even those typically considered safe.

How should Sutrol be stored and disposed of?

Storage Conditions for Sutrol (Metronidazole)

Official regulatory guidelines require Sutrol to be stored at controlled room temperature, generally between 15 - 25 C (59 - 77 F). The medicine must be kept protected from light and excess moisture. Containers, including those for oral forms, must remain tightly closed and use a child-resistant closure to ensure the product is safely stored out of the sight and reach of children. Any oral liquid form must be discarded ten days after the bottle is first opened.

Official Disposal Rules

Unused or expired Sutrol should be disposed of using a drug take-back program or mail-back envelope. If those options are unavailable, regulatory guidance advises mixing the medicine with an undesirable substance (like dirt or coffee grounds) and placing it into a sealed container before discarding it in the household trash. Personal information on all packaging must be scratched out before disposal.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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