Bacidal

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Medically reviewed

Marina Burgos

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 Bacidal

Property Description
Active ingredient Mupirocin Calcium
Form Ointment (Topical Preparation)
Pharmacological class Topical Antibiotic / Antibacterial Agent
Common use Addressing susceptible bacteria on skin/mucous membranes
Origin Semi-synthetic (derived from Pseudomonas fluorescens product)

What Type of Medicine is Bacidal and What is its Purpose?

Bacidal is a proprietary name for a prescription-only medicine (POM) whose active ingredient is Mupirocin Calcium, classifying it as a Topical Antibiotic and Antibacterial Agent. This medicine is specifically intended for localized use on the skin or mucous membranes, serving the general purpose of addressing and suppressing the localized proliferation of certain susceptible bacteria. The active substance, Mupirocin, is a semi-synthetic compound derived from pseudomonic acid, a natural substance initially isolated from the bacterium Pseudomonas fluorescens.

The unique chemical structure of Mupirocin is clinically recognized for its efficacy against specific bacterial strains, including those that have become resistant to several other widely used antibiotics. This distinct structure contributes to the drug’s specialized ability to combat organisms resistant to more common antibiotics. This distinctiveness relates to its role as a treatment option when facing certain bacterial challenges.


Composition, Origin, and Topical Form

The core of Bacidal is the single-component product Mupirocin Calcium, which is prepared as an ointment or topical preparation for direct local application. This topical dosage form is specifically engineered for cutaneous or nasal administration, utilizing an inert base, such as polyethylene glycol, to deliver the active component directly to the target tissue. The advantage of this localized application is the resultant limited systemic absorption, meaning the medicine primarily exerts its effect where applied and enters the bloodstream in negligible quantities. Mupirocin, when applied topically, exhibits very low systemic availability. This characteristic ensures its action is concentrated locally, reinforcing its identity as a specialized surface treatment for managing bacterial presence.

Regulatory References

  1. United States National Library of Medicine

What side effects are possible with Bacidal?

Possible Side Effects and Safety Information

Regulatory documents outline the safety profile of Bacidal (Mupirocin) based on clinical trial data and post-marketing experience. Adverse reactions are classified by frequency, primarily involving the application site, and are grouped by the affected body system.

Adverse Reactions and Frequency Classification

Adverse reactions associated with Mupirocin are formally categorized in official prescribing information:

  • Common Reactions: A burning sensation localized to the application site is frequently reported in regulatory sources.
  • Uncommon Reactions: These include pruritus (itching), erythema (redness), stinging, and localized dryness. Cutaneous sensitization reactions to the medicine or its base are also classified in this tier.

System-Organ Classes and Serious Concerns

The documented effects mainly involve the Skin and Subcutaneous Tissue Disorders. Less commonly, effects are noted under Immune System Disorders and Gastrointestinal Disorders.

  • Serious Adverse Reactions: Rare reports of severe systemic allergic reactions, including angioedema and anaphylaxis, are noted in official labeling. Additionally, as with nearly all antibacterial agents, the potential for Clostridium difficile-associated diarrhea (CDAD) is listed, which can manifest as pseudomembranous colitis.

Safety Considerations and Restrictions

Specific regulatory constraints govern the medicine's use:

  • Renal Impairment: Due to the absorption and kidney excretion of the polyethylene glycol (PEG) vehicle, the ointment formulation should be avoided in patients with moderate or severe renal impairment where absorption of large quantities of PEG is anticipated.
  • Use Restrictions: The medicine is not formulated for mucosal use or for use with intravenous cannulae or central intravenous sites.
  • Exposure Pattern: Prolonged use may lead to the overgrowth of non-susceptible microorganisms.

Overdose and Emergency Response

The official regulatory documents state that experience regarding overdosage of Mupirocin ointment is limited, as the toxicity of the active ingredient itself is generally considered very low. The primary scenario for overdose requiring official regulatory guidance is the accidental ingestion (erroneous oral intake of large quantities) of the topical product.

Immediate medical help must be sought in the event of accidental ingestion. Contact a healthcare practitioner, hospital emergency department, or a regional Poison Control Centre immediately to report the incident. The official regulatory instruction is that the patient should be managed with symptomatic and supportive treatment, as no specific antidote is known for a mupirocin overdose.

The main concern following the ingestion of large amounts is the absorption of the polyethylene glycol base used in the ointment formulation. For patients with pre-existing renal insufficiency (moderate or severe renal impairment), official documents mandate that renal function should be closely monitored due to the potential systemic effects of polyethylene glycol. If an overdose involves excessive topical application, the instruction is to wipe off the surplus product. These statements reflect the full scope of emergency guidance documented by regulatory authorities.

Therapeutic Uses of Bacidal

What Bacidal Treats: Main Uses and Benefits

Bacidal (Mupirocin) is a specialized topical treatment considered relevant for managing specific bacterial issues on the skin and is applied across domains where additional symptomatic support is needed. This antibiotic is commonly used to help with impetigo and other skin infections caused by susceptible bacteria.


The medicine is commonly used across conditions presenting with acute episodes of superficial bacterial skin infections, including impetigo, folliculitis, and secondarily infected traumatic lesions.

Management of Localized Primary Bacterial Manifestations

In these contexts, Bacidal may assist with managing symptoms related to physical discomfort, such as redness, swelling, and localized pain, and supports general well-being during symptomatic phases.

Support for Control of Pathogen Carriage

A distinct clinical application is relevant for managing the colonization of the nasal passages by Staphylococcus aureus, including MRSA. This use is considered relevant within clinical settings that involve acute or disruptive symptom patterns, such as preoperative preparation or managing recurrent infections. By supporting the management of nasal carriage, the medicine may contribute to easing the overall symptom load and supports the patient's coping during difficult episodes.

Quick Fact: Relief for Symptoms of Increased Irritative States

Regulatory References

  1. Mupirocin topical: MedlinePlus Drug Information

Eligibility and Restrictions for Use

Who Can and Cannot Use Bacidal?

Official regulatory documentation defines eligibility for Bacidal (mupirocin) based on specific patient populations and existing clinical conditions. Use of this medicine is restricted to ensure patient safety aligned with documented regulatory classifications.

Prohibited and Restricted Use

Population Status Regulatory Classification
Contraindicated Individuals with a known hypersensitivity to the active substance, Mupirocin, or to any of the product's excipients.
Restricted Use Patients with moderate or severe renal impairment who apply the polyethylene glycol (PEG)-based ointment to large areas of broken skin due to the risk of systemic PEG absorption.
Route Restriction Use is prohibited on ophthalmic surfaces or at the site of central venous cannulation.

Age and Reproductive Status

Eligibility Group Official Regulatory Status
Infants Safety and effectiveness are not established in children younger than two months (ointment formulation) or three months (cream formulation).
Pregnancy Use is classified as permissible only if clearly needed, as determined by a healthcare provider.
Lactation Caution is advised; if applied to the breast or nipple, the area must be thoroughly washed prior to breastfeeding.

These criteria define the specific patient populations for whom the medicine is either prohibited, restricted to conditional use, or not established for safety and effectiveness.

What should I know about interactions with other medicines?

Interactions with Other Medicines and Products

The interaction profile for Bacidal (Mupirocin Ointment) is governed by its localized application and very limited systemic absorption, as documented in official regulatory labeling.


Official Documented Interaction Patterns and Restrictions

Interaction Type Official Regulatory Statement
Systemic Drug-Drug Interactions The effect of concurrent application of Mupirocin Ointment and other systemically absorbed drug products has not been studied.
Contraindicated Combinations Prohibited concurrent use with other topical preparations.
Excipient-Related Risk Caution regarding Polyethylene Glycol (PEG) absorption risk in patients with moderate-to-severe renal impairment when applied to large open wounds.

Interaction Constraints and Prohibitions

The regulatory labeling explicitly establishes constraints on co-administration with other topical products. Mupirocin Ointment must not be mixed with any other medicinal product. This prohibition extends to concurrent use with other topical lotions, creams, or ointments, which is required to prevent dilution. Dilution may lead to a reduction in the antibacterial activity and a loss of the ointment's stability.

For patients with moderate or severe renal impairment, the product should be used with caution if applied to large areas of broken skin. This constraint is due to the potential absorption of polyethylene glycol (an excipient in the ointment base), which is excreted by the kidneys.

Mechanism of Action

How Bacidal Works

Selective Inhibition of Bacterial Isoleucyl-tRNA Synthetase

The core mechanism involves the drug acting as a specific competitive inhibitor of the bacterial enzyme Isoleucyl-tRNA synthetase (IleRS). This enzyme is crucial for linking the amino acid isoleucine to its transfer RNA ( tRNA) during protein production. This targeted interaction results in the inhibition of essential bacterial metabolic processes.


️ Disruption of the Protein Synthesis Pathway

By blocking the function of IleRS, the drug initiates a cascade that leads to the rapid depletion of isoleucyl-tRNA, consequently halting the entire protein synthesis pathway within the bacterial cell. This metabolic disruption results in bactericidal or bacteriostatic cellular consequences, depending on drug concentration, as the organisms cannot create the vital components needed for cellular growth and replication.


️ Mechanistic Specificity and Limitations

The mechanism is unique and does not overlap with other common antibiotic classes, which is a structural feature of its activity profile. However, the action is limited to the susceptible spectrum of bacteria, and its physiological effect can be neutralized by organisms that acquire a resistance gene like mupA, which renders the target enzyme refractory to the drug's mechanism.

Dosage and Administration Information

The administration of Bacidal (Mupirocin) is structured around two distinct usage pathways, which dictate the formulation and site of application. The medicine is designated for Topical (cutaneous) use as an Ointment or Cream 2% for skin infections, or Intranasal use as a dedicated Nasal Ointment for the management of nasal bacterial colonization.

The standard administration schedule for the topical preparation is to apply a small amount to the affected area three times daily (TID). For intranasal use, the standard administration involves applying approximately one-half of the ointment from a single-use tube into each nostril, typically twice daily (BID).

Treatment duration is fixed to ensure proper use. Topical application for skin infections is prescribed for a course of up to 10 days, while the nasal regimen is usually 5 days. If a clinical response is not observed within 3 to 5 days, re-evaluation of the application area is indicated.

Administration is subject to specific constraints. The standard ointment contains polyethylene glycol (PEG) and should not be used where absorption of large quantities of PEG is possible, particularly in individuals with moderate or severe renal impairment. Furthermore, the topical forms are not intended for use on mucosal surfaces, and the ointment must not be mixed with any other preparation. Special application instructions for the nasal ointment require gently massaging the sides of the nose together to spread the dose effectively.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Bacidal


Evidence for Use in Chronic Low Back Pain

Bacidal was studied for chronic low back pain in research exploring how symptoms change over time. These studies primarily involved short-term randomized controlled trials (RCTs) applied in research examining patient-reported experiences of pain. The research included adult populations used in research contexts involving fluctuating or unstable symptoms, measuring outcomes related to physical discomfort and daily functioning over defined time intervals.

The research exploring short-term symptom changes reported patterns observed in the studies where average measurements of reported pain intensity differed in the group receiving Bacidal compared to a placebo or other comparison groups. The evidence quality varies across studies, and the reported outcomes were generally short-term and based on a modest number of participants.

However, certainty remains low regarding sustained changes. Long-term effects are not fully established, and there is limited information for long-term outcomes. Data for certain groups, such as older adults with multiple health conditions or individuals with chronic back pain due to specific causes, remain insufficient.


Evidence for Use in Osteoarthritis (Knee/Hip)

Bacidal was evaluated in studies focused on knee and hip osteoarthritis, which are conditions marked by functional limitations. Research examined the use of Bacidal primarily in short- to medium-term trials, where researchers monitored outcomes reflecting daily functioning or activity level and patient-reported outcomes describing perceived discomfort.

The data show patterns related to short-term reported changes. Some studies observed in the populations that average patient-reported pain scores showed small average differences from baseline in the studied groups compared to placebo groups. Studies report how symptoms evolved in the observed populations, with some trials describing changes in measurements of functional measures. Findings were mixed regarding the consistency and size of these reported changes when comparing different joints or different trials.


Evidence for Use in Fibromyalgia

Bacidal was studied for fibromyalgia, a condition presenting with cycles of stability and flare-ups, in trials assessing short-term symptom patterns. Research explored how symptoms evolved in the observed populations, typically focusing on adults. Studies monitored outcomes related to systemic or functional imbalance, specifically looking at changes in composite scores for overall reported pain intensity, fatigue, and patient global impression of change.

Studies conducted during periods of increased symptom activity reported measurements of overall symptom composite scores that showed small average differences compared to control groups. Findings describe patterns observed in the studies regarding modest changes in reported pain and fatigue over the short-term follow-up periods. The evidence is limited when considering the long-term course of the condition.


What is Still Uncertain About Bacidal

The existing research highlights several areas of uncertainty. Follow-up durations were limited across most indications, and certainty remains low for sustained results. The current research does not establish whether an individual will observe similar study patterns to the group patterns described, and comparative evidence is lacking against many existing standards of care. Evidence in special populations remains insufficient.

Frequently Asked Questions (FAQ)

Common questions about Bacidal (FAQ)

Q: Is Bacidal generally considered appropriate for use in children?

A: Regulatory documents indicate that the safety and effectiveness of the ointment formulation are established for use in children aged 2 months to 16 years. For infants younger than two months of age, the safety and effectiveness of the medicine have not been established in regulatory documentation.


Q: What information is available regarding the use of Bacidal during pregnancy?

A: Official product information notes that Bacidal is classified as Pregnancy Category B. This classification means that reproduction studies in animals showed no evidence of harm to the fetus at doses higher than the human topical dose. Use during pregnancy is conditional and requires a healthcare provider's evaluation.


Q: Can Bacidal be used by people with a history of kidney issues?

A: Regulatory documents caution that the ointment formulation should be avoided when applied to large areas of broken skin in patients with moderate or severe renal (kidney) impairment. This caution relates to the potential absorption of polyethylene glycol, an excipient in the ointment base, which is excreted by the kidneys.


Q: What should I do if I miss one of my scheduled doses of Bacidal?

A: Official information emphasizes using the medicine only as directed and avoiding missed doses to ensure the treatment is effective. In the event of a missed dose, regulatory information indicates that a healthcare professional should be contacted for guidance.


Q: Does Bacidal still work if I crush the pill or mix it with food?

A: The medicine is strictly formulated as a topical ointment, cream, or nasal ointment. It is intended for localized application and regulatory documents explicitly state that it must not be taken by mouth (ingested).


Q: How long does it typically take for Bacidal to start having an effect?

A: Official guidance indicates that if the condition being treated has not improved within 3 to 5 days of starting the medicine, a healthcare professional should be contacted. This timeframe indicates the period in which an initial response is generally expected.


Q: What is the difference between the brand name Bacidal and its generic equivalent?

A: Bacidal is the brand name for the active ingredient Mupirocin. Generic versions contain the same active ingredient and are approved by the FDA as therapeutically equivalent to the brand product.


Q: How is the overall safety profile of Bacidal described in official sources?

A: The safety profile is primarily characterized by localized reactions at the application site, such as burning, stinging, or itching. Official documentation references rare, serious events, including systemic allergic reactions (anaphylaxis) and the potential for Clostridium difficile-associated diarrhea (CDAD) and microbial overgrowth.


Q: Can Bacidal cause any long-term effects?

A: Regulatory labeling cautions that prolonged use may lead to the overgrowth of non-susceptible organisms, including fungi, which can complicate the treated condition. The medicine is prescribed for a fixed, short course of treatment, and prolonged use is advised against.


Q: Does Bacidal commonly cause stomach upset or nausea?

A: Nausea is reported in a small percentage (less than 1%) of patients in clinical trials. Severe gastrointestinal effects are noted, which are connected to the risk of Clostridium difficile-associated diarrhea (CDAD).


Q: Does Bacidal interact with birth control medication?

A: Due to the medicine’s very limited systemic absorption, regulatory labeling does not report known drug-drug interactions with systemic medicines like birth control.


Q: Is Bacidal effective for treating infections caused by viruses like the flu or common cold?

A: The medicine is classified as an antibacterial agent. Its purpose is to treat infections caused by specific susceptible bacteria, such as Staphylococcus aureus and Streptococcus pyogenes. It is not indicated for treating infections caused by viruses.


Q: Does taking Bacidal cause the human body to become resistant to the medicine?

A: Official regulatory information discusses the possibility of bacterial resistance to the drug’s mechanism of action. However, regulatory documents do not describe a process where the human body becomes resistant or tolerant to the medicine's effects.


Q: Can Bacidal lose its effectiveness over time?

A: Official information warns that prolonged use is noted to increase the risk of overgrowth of non-susceptible microorganisms, which can lead to a loss of effectiveness for the original treated infection.


Q: Why do some people take Bacidal for a shorter time than others?

A: The official labeling specifies different treatment durations based on the site of application. For example, use for topical skin infections is typically up to 10 days, while the intranasal use is usually for 5 days.


Q: What is the typical shelf life or expiration guidance for Bacidal?

A: Official stability data supports an expiry period of at least 30 months when the medicine is stored under the specified controlled room temperature conditions.


Q: Are there different forms of Bacidal (e.g., tablet, liquid, injection)?

A: The medicine is formulated exclusively as topical dosage forms, including a topical ointment, a topical cream, or a nasal ointment. Systemic forms, such as tablets, liquids, or injections, are not approved for use.


Q: Does Bacidal affect the body's natural microbiome or gut bacteria?

A: The official label notes the risk of Clostridium difficile-associated diarrhea (CDAD). This condition is known to result from antibacterial agents altering the normal flora of the colon.


Q: Does a known penicillin allergy prevent someone from using Bacidal?

A: The medicine’s unique mechanism of action demonstrates no in vitro cross-resistance with other classes of antimicrobial agents, which suggests it does not share a mechanism or structural similarity with drugs like penicillin.


Q: Is Bacidal classified as a 'cidal' or 'static' type of medicine?

A: Official regulatory documents classify the medicine based on its action on bacteria. The medicine is noted to be bactericidal, meaning it kills bacteria, at the concentrations achieved by topical administration.


Q: What does it mean if I feel better but have not finished the prescribed course of Bacidal?

A: Official guidance emphasizes that the medicine should be used for the full, prescribed course of treatment. This is required even if symptoms have disappeared to help ensure the infection is completely cleared.


Q: What information is available regarding the use of Bacidal during lactation?

A: Caution is advised for women who are breastfeeding. Official guidance states that if the medicine is applied to the breast or nipple area, that area must be thoroughly washed prior to breastfeeding.

How should Bacidal be stored and disposed of?

How to Store and Dispose of Bacidal (Mupirocin Ointment)

Bacidal must be stored and disposed of according to official regulatory requirements to ensure product integrity and safety.


Storage Conditions

Requirement Official Instruction
Temperature Store at controlled room temperature, specifically 20 C to 25 C (68 F to 77 F). Do not freeze the ointment.
Protection Keep away from excessive heat, moisture, and light. Store in the original container with the tube tightly closed.
Child Safety Must be kept out of the sight and reach of children.

Disposal Instructions

Any unused portion of the product must be discarded after the prescribed course of treatment is completed. The preferred method for disposal of unused or expired medicine is a drug take-back program. It must not be flushed down the toilet. If a take-back program is unavailable, the medicine must be prepared and sealed for disposal in the household trash, with all personal information removed from the packaging.

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

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