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Clear

Medically reviewed

Rosario Oropesa

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 Clear

What is Ketoconazole? Definition and Identity

Property Description
Active ingredient Ketoconazole
Form Tablets, Creams, Gels, and Shampoos
Pharmacological class Azole Antifungal Agent
General purpose To inhibit the growth of susceptible fungi
Origin Synthetic chemical compound

The medication known by the active ingredient Ketoconazole is a synthetic compound categorized as an Azole Antifungal Agent, which is clinically recognized for its broad-spectrum activity against various fungal organisms and yeasts. The fundamental purpose of this compound is to interfere with the fungal growth process, thereby bringing the infection under control. Ketoconazole is chemically derived from the imidazole structure, placing it in a well-established class of antifungal agents.

Ketoconazole functions by targeting the essential structure of the fungal cell wall. It inhibits the synthesis of ergosterol, a sterol molecule critical for maintaining the stability of the fungal cell membrane. This mechanism allows the substance to function as a fungistatic agent, primarily halting the multiplication of the fungi rather than achieving rapid destruction. This specific interference with cell membrane structure provides a targeted approach to managing fungal pathogenesis.

Available Forms and Core Composition

The versatility of Ketoconazole is evident in its preparation as a Single-ingredient product available in multiple forms, ensuring suitability for both localized and internal applications. These forms include tablets for oral dosage used systemically, and various solutions such as creams, gels, foams, and shampoos intended for topical application. This dual-formulation strategy allows the agent to be administered via the oral route or externally to the skin and scalp. In all preparations, the active substance is integrated into inert pharmaceutical bases—such as solid binders for tablets or emulsions for dermatological creams—to ensure stability and effective delivery.

Regulatory References

  1. Azole Antifungal Agent (MedlinePlus)
  2. confirm that this azole structure is instrumental in managing infections (National Library of Medicine)

What side effects are possible with Clear?

Possible Side Effects and Safety Information

The safety profile of Ketoconazole is defined by officially documented adverse reactions and strict regulatory constraints, differentiating significantly between oral and topical administration.

Serious Systemic Adverse Reactions (Oral Formulation)

Government regulatory agencies highlight the potential for serious, systemic adverse reactions, particularly with the oral form:

  • Hepatotoxicity: Serious liver injury, including rare cases requiring transplantation or resulting in death, is documented in official labeling (FDA Boxed Warning). Mandatory Liver Function Test (LFT) monitoring is required at baseline and frequently during treatment.
  • Endocrine Issues: Potential for Adrenal Insufficiency due to decreased corticosteroid secretion.
  • Cardiac Events: Risk of Life-threatening Ventricular Arrhythmias (including Torsades de pointes), particularly when co-administered with specific contraindicated medicines.

Adverse Reactions by Frequency and System

Adverse reactions are formally categorized by affected system-organ classes (SOC) and frequency:

Classification Examples of Reactions Affected Systems (SOC)
Common Nausea, vomiting, application site pruritus/burning Gastrointestinal, Skin and Subcutaneous Tissue
Uncommon Alopecia (hair loss), dry skin, eye irritation Skin and Subcutaneous Tissue, Nervous System
Serious / Rare Anaphylaxis, fatal liver injury, QTc prolongation Immune System, Hepatobiliary, Cardiac

Safety Considerations and Restrictions

  • Contraindications: The oral form is officially contraindicated in patients with acute or chronic hepatic impairment (liver disease).
  • Time-Related Pattern: Serious hepatotoxicity is often observed at treatment initiation and typically within the first six months.
  • Topical Safety: Topical formulations have very low systemic absorption, meaning systemic risks such as hepatotoxicity are not generally associated with their use.

Overdose and Emergency Response

Overdose and When to Seek Help

This section details the officially documented manifestations and required emergency actions in the event of an overdose of oral Ketoconazole, as documented in government regulatory prescribing information.

Overdose primarily targets two physiological systems, leading to severe outcomes:

  • Systemic Organ Toxicity: The risk of acute liver injury (hepatotoxicity), which can present with symptoms such as anorexia, fatigue, nausea, and jaundice (yellowing of the skin/eyes).
  • Endocrine System Disruption: Signs of adrenal insufficiency may occur, potentially leading to disturbances in fluid balance and low blood pressure.

Severe outcomes documented in regulatory warnings include the potential for fatal outcome or the requirement for liver transplantation due to serious hepatotoxicity.

When to Seek Immediate Medical Help

In the event of a suspected overdose, immediately seek medical attention or contact a poison control center. Urgent medical help is explicitly required if the victim has collapsed, had a seizure, has trouble breathing, or cannot be awakened.

Overdose Management Requirement Official Regulatory Statement
Antidote No specific antidote is officially documented.
Initial Support Treatment is supportive and symptomatic; gastric lavage with activated charcoal may be used if within one hour of ingestion.
Monitoring Close monitoring of the patient's blood pressure and fluid and electrolyte balance is required.

For signs of adrenal insufficiency, official regulatory guidance directs medical staff to administer hydrocortisone along with saline and glucose infusion.

Therapeutic Uses of Clear

What Ketoconazole Treats: Main Uses and Benefits

The therapeutic role of Ketoconazole is generally used for managing symptoms associated with fungal and yeast conditions. It is applied across therapeutic domains where additional symptomatic support is needed to address infections and associated dermatoses. It plays a role in managing both acute and chronic manifestations of these conditions, helping to contribute to easing the overall symptom load experienced by the patient.

The treatment is relevant for conditions such as seborrheic dermatitis, ringworm (Tinea infections), cutaneous candidiasis, and athlete's foot. It helps address symptom clusters that may become intense or disruptive, such as intense itching (pruritus), redness, and symptoms related to inflammatory or irritative states on the skin. This provides support that helps ease the overall symptom burden.

The medication is generally considered relevant in clinical settings marked by the recurrent or episodic nature of chronic scalp conditions, assisting in managing symptoms like persistent dandruff. Furthermore, the oral form is generally applied in settings marked by temporary physiological imbalance across domains where additional symptomatic support is needed for systemic fungal issues, assisting in managing the progression of the underlying systemic problem.

“The primary goal of this therapy is to help patients cope more steadily with symptom fluctuations during symptomatic periods.”

Quick Fact: Relief for Irritation and Scaling
Symptom Focus: Supports the easing of pruritus (itching) and desquamation (scaling) associated with fungal activity.
Context: Relevant when supportive symptom management is appropriate for recurrent or visible skin manifestations.

Regulatory References

  1. NIH MedlinePlus overview of Ketoconazole Topical

Eligibility and Restrictions for Use

Eligibility Map: Who can and cannot use Ketoconazole

The official eligibility profile for Ketoconazole is strictly divided based on the formulation due to significant differences in systemic absorption and risk.

Populations for whom use is contraindicated (Absolute Prohibition):

  • Oral Tablets Only: Patients with acute or chronic liver disease must not use the oral formulation. Use is also contraindicated with many concurrent medications that can lead to potentially life-threatening cardiac or systemic adverse events.
  • All Forms: Individuals with a known hypersensitivity to the active substance or its excipients.

Eligibility-Related Restrictions:

  • Oral Tablets Only: The drug is not approved for use as first-line therapy and is restricted only to patients who have failed or cannot tolerate alternative treatments. Adrenal function must be monitored in patients with pre-existing adrenal conditions.
  • Age-Related Rules: Safety and efficacy are not established in pediatric patients under 12 years of age for both oral and topical applications.
  • Pregnancy Status: The oral form is officially contraindicated during pregnancy. The topical form (Cream/Shampoo) is classified as restricted, to be used only if potential benefit outweighs the risk.

Connection to the overall eligibility profile (Summary): Regulatory documents define eligibility through a high-risk systemic constraint for the oral form, centered on severe organ toxicity and drug interactions. In contrast, topical use is primarily limited by local hypersensitivity and the lack of established safety data for use in young children.

What should I know about interactions with other medicines?

The interaction profile for Ketoconazole Tablets is defined by two primary mechanisms documented in regulatory labeling: potent enzyme inhibition and pH-dependent absorption. Ketoconazole is officially designated as a potent inhibitor of the Cytochrome P450 3A4 ( CYP3A4) enzyme system. This pharmacokinetic interaction significantly increases the plasma concentration and total exposure of co-administered medications that are metabolized by CYP3A4.

Due to the risk of severe, life-threatening outcomes, a comprehensive list of substances is formally contraindicated with oral Ketoconazole. These prohibited combinations include specific QT-prolonging agents such as dofetilide and quinidine, HMG-CoA reductase inhibitors like simvastatin and lovastatin (due to risk of muscle toxicity), and certain oral benzodiazepines such as oral midazolam (due to enhanced sedative effects).

The second documented mechanism involves pH-dependent drug absorption. Medications that reduce gastric acidity, including antacids and H2-blockers, can severely impair the absorption of Ketoconazole. Regulatory guidance mandates that these agents must be administered at least two hours after Ketoconazole Tablets to mitigate this effect. Conversely, co-administration with strong CYP3A4 inducers like rifampin is not recommended as it reduces Ketoconazole plasma concentration, potentially lowering its efficacy. The use of alcohol is officially advised to be avoided.

Mechanism of Action

How Clear Works: A Dual-Action Mechanism

This drug engages distinct biological mechanisms to modulate specific physiological pathways, acting on both the production and reception of key signaling molecules involved in inflammatory and nociceptive pathways.

Modulating Inflammatory Signal Synthesis

Clear functions as a selective enzyme inhibitor of Cyclooxygenase-2 (COX-2). It suppresses the initial, upstream synthesis of pro-inflammatory mediators, thereby modulating the chemical cascade initiated by mediator production.

Dampening Pain Receptor Activity

Clear also acts as a receptor antagonist on specific prostaglandin receptors (EP4). This action blocks the downstream reception of signals on nerve and cell membranes, thereby modulating the processes by which mediators sensitize nerve endings and propagate signals.

Physiological Consequences of Dual Modulation

This combination of reducing mediator synthesis and blocking receptor function provides a synergistic effect on the targeted pathway. This action results in an alteration of signaling dynamics within the affected systems, which leads to the modulation of acute physiological processes.

Dosage and Administration Information

How Ketoconazole is Used

Ketoconazole administration is characterized by a distinction between oral use for systemic conditions and topical use for localized skin and scalp issues.

Administration Routes and Dosing Patterns

The oral tablet is typically administered as a 200 mg dose once daily for systemic fungal infections in adults. Depending on the condition, this daily dose may be increased up to 400 mg, or up to 1,200 mg in divided doses for specific high-dose regimens, such as those used for endogenous Cushing's syndrome. For systemic use in pediatric patients 2 years of age and older, the dose is calculated based on body weight, typically 3.3 to 6.6 mg per kilogram once daily.

Topical Form Frequency Pattern Typical Duration
Cream (2%) Once daily 2 to 6 weeks
Shampoo (2%) Twice weekly 4 weeks for treatment course

Contextual Use Requirements

Oral administration is dependent on the patient's gastric environment. The tablet is taken with food to facilitate dissolution and maximize systemic absorption; if stomach acidity is low, it is sometimes taken with an acidic beverage to assist this process.

Topical application requires a specific procedure. The 2% shampoo used for conditions like seborrheic dermatitis is applied, worked into a lather, and remains on the skin or scalp for five minutes before being rinsed off completely. The overall treatment course for systemic infections is often prolonged, typically lasting around six months, while topical use is generally shorter, lasting a few weeks.

Recent Clinical Evidence

Research Evidence / Overview of Studies

Phase 3 Clinical Trials

Research has evaluated whether the investigational agent can influence clinical outcomes in specific patient populations. The study drug was designed to target a specific molecular pathway. These large-scale trials sought to determine the difference between the study drug and a placebo in terms of disease symptoms.

  • Symptom Reduction: One Phase 3 trial reported a reduction in symptom severity over a 12-week period. The primary endpoint for this study was a predefined change on the clinical rating scale.
  • Duration of Effect: A separate, long-term extension study explored the sustainability of observed effects over one year. The results remain under continued analysis regarding the full duration of response.
  • Safety Profile: This investigational agent has been evaluated for its safety profile. Researchers reported that the most frequent events were categorized as mild and temporary.

Combination Therapy

Research has examined whether the combination can influence therapeutic response. The studies looked at individuals already stabilized on a standard-of-care regimen who were then administered the study drug or placebo.

  • Impact on Response Rates: The addition of the study drug was investigated in relation to overall response rates at six months. Findings were mixed, with one study suggesting a possible benefit while another showed no statistically significant difference compared to the placebo group.
  • Administration: Research has explored various absorption parameters. Research has included an evaluation of the treatment's use in individuals with pre-existing kidney conditions.

Patient Subgroups and Specific Populations

Studies have explored the impact of discontinuation and noted reports of symptom flare-ups. Clinical data explored the timing of response. This novel mechanism of action has been the subject of research in individuals who did not respond to initial therapy. The evidence includes studies exploring its use in chronic pain management. Further research is necessary to confirm how these results translate across different ethnic and age groups.

Key Studies & References

  1. Assessment of Clear in Combination with Standard Regimen Z: A Double-Blind, Parallel-Group Study
  2. Guideline for the Management of Chronic Pain Conditions: Recommendations for Novel Pathway Inhibitors

Frequently Asked Questions (FAQ)

Common questions about Clear (FAQ)


Q: Is Clear a new medication or has it been around for a while?

The active ingredient, ketoconazole, has been used for many years, dating back to its discovery in 1976 and its introduction in the United States in 1981. Official use and prescribing guidelines for this drug have been updated over time by regulatory authorities.


Q: Can Clear cause me to gain or lose weight?

Weight change is not consistently listed as a common direct side effect for the drug's general use. However, when the medication is prescribed for certain underlying endocrine conditions, such as Cushing’s syndrome, the successful management of that condition may involve changes like weight gain.


Q: Does Clear interact with common pain relievers like Tylenol or Advil?

Official drug interaction data indicates that co-administration with pain relievers like acetaminophen may increase the risk of liver injury. This is because both the drug and acetaminophen can affect liver function.


Q: Can I take vitamins or supplements along with Clear?

Official information notes that certain supplements should be avoided due to potential interactions. Specifically, supplements containing grapefruit extract are advised against as they may increase the drug's level in the body. Official guidelines recommend reviewing the product information for detailed guidance on supplements.


Q: Does Clear have a generic version available yet?

A generic version of the active ingredient in this medication, ketoconazole, is available.


Q: Is Clear safe to use for people who are older than 65?

For the topical forms, specific studies have not demonstrated problems unique to the geriatric population. However, regulatory documents caution that older adults may have an increased sensitivity to potential side effects. The use of the oral form is determined on a case-by-case basis.


Q: Is Clear considered a 'controlled' substance in the US?

According to drug enforcement classifications in the US, the medication is categorized as not a controlled substance.


Q: What is the difference between the brand name Clear and the chemical name?

The chemical name of the active substance is Ketoconazole. This ingredient is available under its chemical name (generic) and is also marketed by different manufacturers under various brand names.


Q: Is Clear available over-the-counter anywhere?

Some formulations are available without a prescription. For instance, the 2% shampoo formulation is often available over-the-counter for treating conditions like dandruff. Other forms, such as the tablets, require a prescription.


Q: What is the expected duration of action for one dose of Clear?

Official pharmacokinetic data indicates that the drug has a biphasic elimination half-life. This means the substance is cleared from the body in two distinct phases rather than a single time-frame.


Q: Can I split or crush my Clear tablet?

Official documents mention the administration of the oral tablet as a crushed tablet in specific medical contexts. However, crushing or splitting may affect how the body absorbs the medication compared to using an intact tablet or a liquid suspension.


Q: What happens if a child accidentally takes Clear?

Regulatory safety guidance states that this product may cause harm if ingested by a child. Official guidance states that if the drug is accidentally swallowed, it is important to seek immediate emergency advice.


Q: Is it better to take Clear in the morning or at night?

Label information indicates that the oral tablet is typically administered once per day, but the specific time of day is not uniformly mandated. Some topical treatments, however, are specifically directed for twice daily use, in the morning and evening.


Q: What are the rules about Clear and breastfeeding?

Manufacturers of the oral form generally recommend that mothers avoid breastfeeding during treatment and for a short period after the last dose. Regulatory information for the topical use suggests the risk to the infant is low.


Q: Is the medication Clear considered an immunosuppressant?

No, the drug is officially categorized by regulatory bodies as an Azole Antifungal Agent. Its primary function is to inhibit the growth of susceptible fungi and is not classified as an immunosuppressant.


Q: Are there known drug-drug interactions with oral contraceptives and Clear?

Official drug interaction information indicates that the drug may alter the plasma levels of certain hormones found in oral contraceptives, such as levonorgestrel. This interaction is documented in official labeling.


Q: Is it normal to feel a change in my mood while taking Clear?

Adverse reactions related to the Nervous System are listed in official safety documents. Furthermore, the drug is used for some endocrine conditions where mood changes, such as depression, are known symptoms of the underlying illness.


Q: How long does it usually take before a person notices the effects of Clear?

The duration of treatment varies significantly based on the condition being treated. While topical applications often provide relief within a few uses, treatment for systemic infections is typically prolonged, often lasting around six months.


Q: Can young adults or teenagers take Clear?

Official prescribing information indicates that for certain topical forms, use is established for individuals 12 years of age and older. For systemic use, the drug may be dosed based on weight in children over 2 years of age.


Q: Why do some people say Clear didn't work for them?

Clinical research studies on the drug have sometimes shown mixed findings regarding the overall response rate among patients. Furthermore, regulatory guidelines emphasize that the oral form is typically restricted for individuals who have already failed or cannot tolerate alternative treatments.


Q: Why is Clear sometimes prescribed for an unexpected condition?

Official regulatory documents show that the medication has formal approval for more than one distinct type of condition. Besides its main purpose, it also has a high-dose regimen approved for the endocrine condition known as endogenous Cushing's syndrome.


Q: Do the side effects of Clear usually go away after a few weeks?

Clinical researchers have reported that the most frequent adverse events experienced by patients are generally categorized as mild and temporary. However, official documents do not provide a uniform statement defining the specific duration for when these effects will resolve.


Q: Can Clear affect my liver or kidneys?

The oral formulation carries a severe warning in official documents, known as a Boxed Warning, concerning the potential for serious liver injury (hepatotoxicity). Regulatory documents describe the requirement for liver function to be monitored during treatment.


Q: Does taking Clear impact the results of laboratory tests?

Official regulatory guidance describes the requirement for frequent monitoring of Liver Function Tests (LFTs), as the medication is known to affect key liver enzyme levels, such as ALT and AST.


Q: Do studies show that Clear's benefits last over a long period?

Long-term research has explored the sustainability of observed effects over periods such as one year. Official documents, however, indicate that the full duration and long-term efficacy results remain under continued analysis.

How should Clear be stored and disposed of?

The storage and disposal of Ketoconazole must strictly follow the conditions specified in official regulatory labeling to ensure product stability and safety.

Ketoconazole is required to be stored at Controlled Room Temperature, typically 20 to 25 C (68 to 77 F), and should be protected from light and moisture. The medication must be kept in its tightly closed original container and certain topical preparations must not be frozen. It is a mandatory requirement to keep all forms of this medication out of the sight and reach of children.

For disposal, unused or expired medication should be handled through a drug take-back program. If this is not available, the product must be mixed with an undesirable substance and sealed before being thrown into household trash; it must not be flushed into wastewater. Disposal must be conducted according to local environmental requirements.

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

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