Klaret

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Medically reviewed

Marina Burgos

Last updated on 10/01/2026

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 Klaret

Klaret is a prescription-only medicine whose active component, Clarithromycin, is specifically classified as a macrolide antibiotic. This medication's primary purpose is the effective treatment of bacterial infections by targeting and neutralizing susceptible pathogens throughout the body.


Quick Facts: Klaret

Property Description
Active ingredient Clarithromycin
Form Tablet, Granules for oral suspension
Pharmacological class Macrolide antibiotic
Common use Treatment of bacterial infections
Origin Semisynthetic

What Type of Anti-Infective Medicine is Klaret?

Klaret belongs to the macrolide family, which is a key group within the broader category of anti-infective agents. The active pharmaceutical ingredient (API) is Clarithromycin, a compound that was developed as a chemical modification of the older macrolide, Erythromycin. This distinction is clinically recognized because macrolides are frequently used when patients have demonstrated allergies or resistance to other common antibiotic classes, such as penicillin. Clarithromycin is recognized as an effective anti-infective agent used to eliminate bacterial pathogens.


Clarithromycin: Composition, Origin, and Available Forms

The therapeutic strength of Klaret relies solely on its Clarithromycin content, which is designated as a semisynthetic compound. This means the substance is chemically derived and enhanced from a naturally occurring macrolide structure, giving it improved properties like superior acid stability and overall absorption. Klaret is prepared for oral administration in two main dosage forms: the solid, film-coated tablet and the liquid granules for oral suspension. This dual availability ensures the medicine can be conveniently delivered to all patient groups, particularly pediatric patients who may require a liquid formulation. Clarithromycin exhibits a superior pharmacokinetic profile compared to first-generation macrolides.


How Does Klaret Work on Bacteria? (High-Level Principle)

Klaret's fundamental action is centered on disrupting the bacteria's process of building essential proteins. The drug works by binding specifically to the bacterial 50S ribosomal subunit, the site where protein synthesis occurs. By interfering with this crucial step, the drug stops the infectious organisms from multiplying, which is referred to as a bacteriostatic action. This principle of inhibiting bacterial growth enables the patient's immune system to effectively clear the infection.

What side effects are possible with Klaret?

The safety profile of Klaret (Clarithromycin) is categorized by regulatory bodies based on the frequency and system of adverse reactions observed in clinical trials and post-marketing data. This information is strictly descriptive and non-advisory.

Adverse Reaction Scope

Category Regulatory Statements
Key adverse reaction categories Gastrointestinal disturbances, Nervous system effects, Cardiac risks, Hepatobiliary dysfunction, Skin/Hypersensitivity.
Frequency classification Common (1/100 to < 1/10) include taste perversion (dysgeusia), headache, diarrhea, nausea, vomiting, abdominal pain, and rash. Uncommon (1/1,000 to < 1/100) reactions involve anxiety, vertigo, and palpitations.
System-organ classes involved Gastrointestinal, Nervous System, Cardiac Disorders, Hepatobiliary, and Skin and Subcutaneous Tissue are cited frequently in official documentation.
Serious adverse reactions Official labeling highlights rare but critical safety outcomes, including QT prolongation and Torsades de Pointes (severe cardiac arrhythmia), and hepatic failure, which has been reported with fatal outcomes. Severe skin reactions such as Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are also documented.

Safety Considerations and Restrictions

Official documents outline specific safety constraints. Klaret is not recommended in patients with a history of QT prolongation or ventricular cardiac arrhythmia. Caution is required for individuals with severe renal impairment and hepatic impairment as these conditions can affect the clearance of the medicine. The drug is excreted into human milk, requiring specific consideration during lactation. These statements serve to define the medicine's risk profile based on governmental regulatory classification.

Overdose and Emergency Response

Klaret (Clarithromycin) overdose is primarily characterized by officially documented gastrointestinal disturbances, including nausea, vomiting, abdominal pain, and diarrhea. Administration of high doses has also been associated with the observation of transient hearing loss.

The regulatory profile emphasizes the potential for serious and life-threatening outcomes primarily affecting the cardiovascular and hepatic systems. These include the risk of prolonged cardiac repolarization (QT prolongation) leading to severe ventricular cardiac arrhythmias, such as Torsade de Pointes. Cases of severe, though usually reversible, hepatic dysfunction or failure have also been officially documented.

Patients must seek immediate medical attention and contact emergency services if an overdose is suspected or if severe manifestations occur, such as collapse or respiratory difficulty. Management described in official sources is supportive and symptomatic, with no specific antidote known. It includes the provision of supportive treatment, prompt procedures for the elimination of unabsorbed drug, and continuous monitoring of cardiac function due to the potential for life-threatening arrhythmias. Special consideration is noted for patients with severe renal impairment due to reduced drug clearance and those with pre-existing coronary artery disease due to documented long-term risk.

Therapeutic Uses of Klaret

What Klaret Treats: Main Uses and Benefits

Klaret is applied across domains where additional symptomatic support is needed in contexts involving heightened systemic burden. The medication is commonly used across conditions presenting with acute episodes and may assist in addressing symptom clusters that may become intense or disruptive. The medication is considered relevant for addressing conditions presenting with systemic or localized discomfort in the respiratory tract (e.g., pneumonia, sinusitis, acute bronchitis), skin and soft tissues (e.g., cellulitis and impetigo), and is relevant in contexts involving heightened systemic burden for H. pylori related to duodenal ulcers and MAC disease in vulnerable patients.

“The primary therapeutic role is focused on helping to ease the overall symptom burden associated with acute or disruptive episodes.”

This medicine is considered relevant for managing symptoms that interfere with daily comfort, such as fever, swelling, and localized pain, applied during phases when symptoms become more noticeable. This provides support that helps patients cope more steadily with symptom fluctuations and assists with maintaining functional stability.


Quick Fact: Relief for Symptoms Associated with Acute Episodes

Klaret is frequently used in clinical settings that involve acute or unstable symptom patterns, contributing to improved comfort during periods of heightened symptoms associated with acute or disruptive episodes.

Regulatory References

  1. NIH MedlinePlus overview of Clarithromycin

Eligibility and Restrictions for Use

Eligibility and Contraindications

Klaret (Clarithromycin) eligibility is strictly defined by regulatory bodies through exclusions and limitations based on patient characteristics and co-existing conditions.

Who Must Not Use Klaret (Contraindicated)

Klaret is strictly contraindicated for use in populations with a known hypersensitivity to clarithromycin or any macrolide antibiotic. It must not be used by patients with a history of QT prolongation or ventricular cardiac arrhythmia, hypokalaemia, or severe hepatic failure combined with renal impairment. Use is also prohibited when taken with certain medications, including lovastatin, simvastatin, and ergot alkaloids, due to the risk of serious adverse reactions.

Restrictions and Limitations

Severe renal impairment (creatinine clearance less than 30 mL/min) requires the total daily dosage to be reduced. Caution is advised for patients with non-severe impaired hepatic function or pre-existing cardiac conditions. Safety and efficacy are not established for infants younger than six months of age. Use is not recommended during pregnancy or lactation as safety has not been established and the medicine is excreted into human breast milk.

What should I know about interactions with other medicines?

Klaret's official interaction profile is defined by its role as a strong inhibitor of the CYP3A enzyme and the P-glycoprotein (P-gp) transporter. This dual inhibitory action significantly increases the plasma concentration and exposure of co-administered medicines that are metabolized or transported by these pathways.

Interaction Scope Official Regulatory Information
Mechanistic Basis Inhibitor of Cytochrome P450 3A (CYP3A) and P-glycoprotein (P-gp) transporter.
Contraindicated Combinations Astemizole, Cisapride, Pimozide, Terfenadine, Domperidone (risk of QTc prolongation). Ergotamine, Dihydroergotamine (risk of ergot toxicity). Lovastatin, Simvastatin (risk of myopathy/rhabdomyolysis). Lomitapide, Ranolazine, Ticagrelor, Lurasidone, Oral Midazolam.
Timing Requirement Oral Zidovudine must be administered at least 4 hours apart from Klaret to avoid reduced absorption of Zidovudine.
Population-Specific Note Co-administration with Colchicine is contraindicated in patients with pre-existing renal or hepatic impairment.

The regulatory framework classifies certain combinations as Strictly Contraindicated Combinations due to significant safety risks. This structure mandates that therapy with certain statins must be suspended during Klaret treatment. The official profile further includes caution for co-administration with other QTc-prolonging agents due to the documented risk of additive cardiac arrhythmia, and requires frequent monitoring when combined with oral anticoagulants like Warfarin.

Mechanism of Action

Klaret (Ticagrelor) is an antiplatelet agent that modifies key signaling pathways to influence specific physiological responses in systems requiring rapid pathway modulation.

Selective Receptor Antagonism

Klaret acts within domains involving receptor-mediated signaling by functioning as a selective, reversibly binding P2Y12 receptor antagonist. It specifically engages the P2Y12 receptor on the surface of platelets. This molecular engagement blocks the typical binding of adenosine diphosphate (ADP), a critical mediator of platelet activity.

Platelet Activation Pathway Modulation

By inhibiting the P2Y12 receptor, Klaret modifies early molecular steps, suppressing the intracellular signaling sequence (involving Galpha i2 protein) that normally leads to the inhibition of adenylyl cyclase. This action alters the cascade, ultimately limiting the downstream processes that rely on ADP signaling for full activation.

Modulation of Platelet Function

The resulting physiological effect alters feedback regulation within targeted pathways. By blocking the final steps of activation, Klaret modulates the effect of excessive mediator activity (like ADP) and inhibits platelet aggregation. This leads to specific adjustments in the aggregation capacity of platelets.

Dosage and Administration Information

Instruction Map: How to use Klaret — Administration Guidelines

The usage protocol for Klaret (Clarithromycin) is determined by the specific dosage form and the patient's renal status for proper administration.

Instruction Detail
Route of administration: Primarily Oral (tablets and suspension), with an Intravenous (IV) option approved for use in certain hospital settings.
Dosing schedule: Standard doses for immediate-release (IR) forms are typically 250 mg to 500 mg per dose. The extended-release (ER) form is typically dosed at 1000 mg once daily.
Timing in relation to meals (if applicable): The ER tablet must be taken with food. IR tablets and the oral suspension may be administered without regard to meals.
Preparation requirements (if applicable): Granules for oral suspension must be reconstituted with water before initial use, and the final suspension must be shaken well before measuring each dose.
Age-group administration rules: The pediatric dosage is calculated based on body weight (mg/kg). Dose is reduced by 50% in patients with severe renal impairment (Creatinine Clearance < 30 mL/min).
Missed-dose rules: A missed dose should be taken as soon as it is remembered, but the subsequent dose should not be doubled.
Special procedural conditions: The ER tablet must be swallowed whole and must not be crushed, broken, or chewed.

Instruction Classifications (High-Level)

Classification Detail
Administration method type: Oral (primary)
Frequency pattern: Twice daily (q12hr) or Once daily (q24hr)
Standardized criteria: Clinical standards
Use-context constraints: Food-dependent (ER tablets), Organ-function dependent (renal impairment), Formulation-integrity dependent (ER tablets must be swallowed whole).

Resulting Procedural Structure

Established step sequence:

  • Immediate-release forms are generally taken twice daily over a short, fixed course, typically lasting 7 to 14 days.
  • Extended-release tablets must be swallowed whole with food to maintain the drug’s intended release profile.
  • Dose adjustment is mandatory for patients with severe kidney impairment.

Connection to the overall use protocol (2–4 sentences): This protocol establishes Klaret’s use through specific administrative procedures that ensure consistent drug exposure. These instructions define the required frequency, the importance of maintaining the physical integrity of the extended-release formulation, and the mandatory dose reduction necessary for patients with reduced kidney function.

Recent Clinical Evidence

Recent Clinical Evidence

Mechanism of Action Studies

Studies were conducted to examine the drug's mechanism, which involves modulating inflammatory pathways. Researchers explored whether this mechanism is associated with changes in symptom levels. These initial investigations primarily used in vitro and animal models to map the pharmacological activity before human trials began.


Phase III Clinical Trials

Two large-scale Phase III Randomized Controlled Trials (RCTs) evaluated the drug's effect on patient-reported quality of life (QoL) and assessed whether pain scores changed over the study period. A total of n=1,250 participants with moderate to severe disease activity were included across the two trials.

  • Primary Endpoint: The study design focused on assessing changes in Disease Activity Score (DAS) from baseline to week 12. Researchers evaluated reports of flare-up frequency in participants receiving the drug compared to the control group.
  • Safety Profile: Adverse events (AEs) were monitored throughout the trials. The incidence of serious adverse events (SAEs) was low and comparable to the control group in the short term.

Combination Therapy Research

Research has been conducted to compare the drug's use as a monotherapy versus combination therapy with a standard disease-modifying agent.

Therapy Type Observation on Symptom Changes
Combination Therapy Changes in symptom levels were observed earlier compared to monotherapy.
Comparative Studies Research evaluated differences in measured outcomes, such as changes in disease activity scores, against other approved treatments.

Long-Term Follow-up

Long-term extension studies monitored for adverse events and assessed whether symptomatic changes persisted over extended periods. Researchers monitored for adverse events and changes in symptomatic changes. The longest follow-up period reported to date is three years. Research protocols for some studies included a follow-up phase to assess outcomes after treatment discontinuation. Data collection remains ongoing.

Frequently Asked Questions (FAQ)

Common questions about Klaret (FAQ)

Q: How is Klaret different from other drugs used for the same condition?

A: Klaret is classified as a macrolide antibiotic, which works by interfering with the bacteria's process of building essential proteins. Official information notes that this class of medicine is frequently used when individuals have documented allergies to other types of antibiotics, such as penicillin.

Q: Can Klaret affect my ability to drive or operate machinery?

A: Regulatory information indicates that Klaret can affect alertness or coordination in some individuals. Due to this potential effect, regulatory documents state that precautions should be taken regarding driving or operating machinery until the patient knows how the medicine affects them.

Q: Is there a generic version of Klaret available?

A: Klaret is the brand name for the active pharmaceutical ingredient clarithromycin. Regulatory documents and public health information often refer to the medicine by its generic name, confirming that the generic form is available.

Q: Is Klaret a common type of medicine for its condition?

A: Klaret belongs to the macrolide class of antibiotics, which are a major and widely recognized group of anti-infective agents. This class plays a significant role in treating certain bacterial infections according to official guidelines.

Q: Does Klaret cure the condition or just manage the symptoms?

A: Klaret's action, described as bacteriostatic, means it works by stopping the infectious bacteria from multiplying and spreading. This disruption of growth enables the body's natural immune system to clear the infection, rather than providing a definitive 'cure' itself.

Q: What are the most common side effects of Klaret?

A: Official product information lists common side effects, which occur in at least 1 out of every 100 people. These include a change in taste (taste perversion), headache, diarrhea, nausea, vomiting, abdominal pain, and rash.

Q: Is it normal to feel tired when starting Klaret?

A: Official documentation lists headache as a common effect of the medicine. Tiredness or fatigue is listed among the less common side effects reported in official documents.

Q: Can I drink alcohol while taking Klaret?

A: Regulatory sources generally indicate that there is no known harmful interaction between Klaret (clarithromycin) and alcohol. Official documentation should be consulted regarding any potential interactions with alcohol.

Q: How quickly does Klaret start working?

A: Pharmacokinetic studies indicate that Klaret reaches its peak concentration within two to three hours after being taken. The stable level needed to fight infection, called steady-state concentration, is typically achieved within about three days of continuous use.

Q: How long do I need to take Klaret?

A: The duration of treatment with Klaret is determined by the specific infection being treated. Official use protocols state that immediate-release forms are typically prescribed for a short, fixed course, often lasting between 7 to 14 days.

Q: Why does the official leaflet mention a certain risk factor for Klaret?

A: Official risk factors, such as the potential for QT prolongation (a type of heart rhythm change) or hepatic failure (severe liver problems), are included in regulatory documents. This serves to define the medicine’s risk profile and inform patients about potential critical safety outcomes reported in clinical data.

Q: What is the purpose of the boxed warning, if Klaret has one?

A: Klaret does not carry an official boxed warning on its current label. However, the FDA has issued warnings concerning a potential increased risk of heart problems and death in certain patients, particularly those with pre-existing heart disease.

Q: Is the long-term safety of Klaret known?

A: The FDA reviewed studies, including follow-up data up to 10 years, on patients who took a two-week course of Klaret. Observational studies suggest an association between Klaret and a potential increased risk of heart problems years later in individuals with pre-existing heart disease.

Q: Are there common misunderstandings about what Klaret is used for?

A: Official information explicitly clarifies that Klaret is an antibiotic used to treat bacterial infections. Regulatory bodies stress that the medicine is not effective against infections caused by viruses, such as the common cold or the flu.

Q: Can I take Klaret if I have a history of heart problems?

A: Official documentation classifies Klaret as contraindicated, meaning its use is restricted, in patients with a history of QT prolongation or ventricular cardiac arrhythmia (an irregular heart rhythm). For other types of heart disease, official documents advise weighing the benefits and risks due to potential long-term cardiac concerns.

Q: How does Klaret affect the body's natural processes?

A: Official documentation outlines that Klaret has potential effects on several human systems, as evidenced by its list of reported adverse reactions. These systems include gastrointestinal, nervous system, cardiac, liver, and skin/subcutaneous tissue.

Q: Is Klaret approved in countries outside the US?

A: The active ingredient in Klaret, clarithromycin, is approved for use in many regions outside the US. This is confirmed by the existence of official regulatory documents, such as the Summary of Product Characteristics (SmPC) published by governmental bodies like the European Medicines Agency (EMA).

Q: What is the official definition of the condition Klaret treats?

A: Official labeling defines that Klaret is indicated for the treatment of various specific infections caused by susceptible strains of bacteria. The official indications list numerous conditions and pathogens that the medicine is approved to target.

Q: Why might a doctor switch me from a different medicine to Klaret?

A: Regulatory documents indicate that macrolides like Klaret are frequently used when a patient has a known allergy to another antibiotic class, such as penicillin. It is also used when an infection is caused by bacteria that may be resistant to other treatments.

Q: Is Klaret often taken with other medications for the condition?

A: Yes, official use protocols and research findings confirm that Klaret is commonly prescribed as part of a combination therapy regimen with other agents. This approach is often required for treating certain complex bacterial infections, such as those caused by H. pylori.

Q: What kind of studies support the use of Klaret?

A: The use of Klaret is supported by evidence from Phase III Randomized Controlled Trials (RCTs). These are large-scale studies that compared the drug's effects and safety profile against a control group or other approved treatments.

How should Klaret be stored and disposed of?

Storage and Disposal Requirements

Klaret (Clarithromycin) must be stored strictly according to official regulatory guidelines to maintain its stability. Tablets require controlled room temperature, typically 20 C to 25 C. All forms must be protected from light and excess moisture and kept in the tightly closed, original container.


Dosage Form Mandatory Storage Condition
Tablets Store at room temperature (20 C to 25 C) and keep from freezing.
Suspension (Liquid) Do not refrigerate. The mixed suspension must be stored between 15 C and 30 C and discarded after 14 days.

All medicine must be stored out of the sight and reach of children.

For disposal, unused or expired Klaret should not be thrown away via wastewater. Patients should consult a pharmacist or healthcare professional for instructions on local drug take-back programs.

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

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