Harpoon

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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 Harpoon

Quick Facts

Property Description
Active ingredient Ofloxacin (single-agent) pm Ornidazole (combination)
Form Tablet (Oral), Solution (Ophthalmic, Otic)
Pharmacological class Fluoroquinolone Antibiotic pm Nitroimidazole Antimicrobial
General purpose Elimination of bacterial and parasitic infections
Origin Synthetic

What Type of Anti-Infective Medicine is Harpoon?

Harpoon is the brand name for a synthetic pharmaceutical agent classified primarily as a fluoroquinolone antibiotic, with its core active ingredient being Ofloxacin. As an antibiotic, it is a prescription-only agent used to combat infectious diseases caused by susceptible bacteria. The fluoroquinolone class is clinically recognized for its reliability against a broad range of bacterial types.


Understanding the Composition and Available Forms

The composition dictates the medicine's full spectrum of activity, as Harpoon is supplied in both single-agent and combination forms, a key differentiating factor. While single-agent Ofloxacin preparations target bacteria, products such as Harpoon OZ are fixed-dose combination products that incorporate a second active ingredient, Ornidazole—a potent nitroimidazole antimicrobial. Combining agents like Ofloxacin and Ornidazole is a formulation strategy to expand coverage against mixed bacterial and protozoan infections. This strategic formulation provides a comprehensive approach to managing multi-pathogen infections. Harpoon is available as an oral tablet for systemic administration and as a sterile solution for topical delivery to the eyes (ophthalmic) or ears (otic).


What is the General Purpose of Harpoon?

The general purpose of Harpoon is to provide a definitive therapeutic intervention by eradicating pathogenic microorganisms. Its action is bactericidal, meaning it actively kills the infectious bacteria, and in its combination forms, it is supplemented with specific anti-parasitic activity. The medication works to systematically eliminate the source of the infection, thereby relieving the microbial burden on the body. It is important to note that, as an antibiotic, the medicine is only effective against susceptible microbial organisms and is ineffective against viral illnesses.

What side effects are possible with Harpoon?

Possible Side Effects and Safety Information

The safety profile of Harpoon, primarily containing the fluoroquinolone antibiotic Ofloxacin, is structured by formal regulatory classifications detailing potential adverse reactions and official safety constraints. These classifications are grouped by frequency and the physiological system affected.


Frequency-Classified Adverse Reactions

Official prescribing information classifies reactions based on incidence:

  • Common: Includes gastrointestinal effects such as nausea, diarrhea, and vomiting, along with nervous system reactions like headache and dizziness.
  • Uncommon/Rare: Reactions such as agitation, sleep disorders, skin rash, arthralgia, and myalgia are documented at lower frequencies.
  • Very Rare/Not Known: Includes highly infrequent but serious events such as severe blistering skin reactions and Aortic Aneurysm and Dissection.

Serious Adverse Reactions and Safety Constraints

Regulatory agencies highlight specific risks that require careful consideration, typically associated with the fluoroquinolone class:

  • Tendon Damage and Neuropathy: Serious reactions include tendon rupture (e.g., Achilles tendon), which may occur during or several months after treatment cessation, and potentially irreversible peripheral neuropathy that can develop rapidly.
  • Metabolic and Psychiatric Events: Other highlighted concerns include severe hypoglycemia (low blood sugar) and psychiatric reactions, including suicidal ideation.
  • Safety Restrictions: The medicine is generally contraindicated in individuals with a history of tendon disorders related to previous fluoroquinolone use and requires caution in older adults due to increased risks of tendon problems and cardiac rhythm disturbances (QT prolongation).

These domains establish the official boundaries of the medicine's risk profile, detailing expected effects, highlighting serious documented reactions, and outlining specific patient safety limitations.

Overdose and Emergency Response

The official regulatory documents define the overdose profile of Harpoon around acute manifestations and mandatory emergency action. The profile describes symptoms resulting from high drug plasma concentrations substantially exceeding the recommended therapeutic regimen.

Documented Overdose Presentations and Physiological Risk Reports of acute overdose include central nervous system (CNS) manifestations such as dizziness, confusional states, impaired consciousness, and the potential for convulsions (seizures). Gastrointestinal effects like nausea and mucosal erosions are also documented. The most serious systemic risks, as stated in regulatory labeling, involve the CNS and the cardiovascular system, the latter due to the potential for QT interval prolongation and subsequent cardiac dysrhythmias. The potential for increased overdose severity is noted in patients with impaired renal function due to reduced drug clearance.

Required Emergency Response and Management Regulators explicitly mandate that patients must seek immediate medical attention and contact emergency services if an overdose is suspected. Due to the severe risks involved, hospital monitoring is required for observation and management. The official label states that no specific antidote is known, confirming that management must focus on symptomatic and supportive treatment. Procedural interventions such as gastric lavage and activated charcoal may be considered as part of the initial supportive strategy.

Therapeutic Uses of Harpoon

Quick Facts: Harpoon Therapeutic Focus

  • Relapsed/Refractory Multiple Myeloma: Used to address this blood cancer in patients who have received multiple prior lines of therapy.
  • Small Cell Lung Cancer (SCLC): Investigated for the treatment of this type of neuroendocrine tumor.
  • Metastatic Castration-Resistant Prostate Cancer (mCRPC): Applied in studies targeting advanced prostate cancer.

Harpoon refers to a portfolio of investigational drug candidates that are currently under clinical evaluation for various types of cancer. These agents are designed to address unmet needs in both solid tumors and hematologic (blood) malignancies.

One compound is being studied to help manage relapsed or refractory multiple myeloma (RRMM), a serious condition where the cancer has returned or failed to respond to previous treatments. For patients with this diagnosis who have already received several lines of therapy, this agent may offer a novel therapeutic approach. This program has been granted Orphan Drug Designation to support its development for this condition.

Other compounds within the Harpoon development pipeline are focused on specific solid tumors. This includes an agent being investigated for the treatment of small cell lung cancer (SCLC) and other advanced cancers associated with Delta-like canonical Notch Ligand 3 (DLL3) expression. Additionally, another candidate is in clinical trials for patients managing metastatic castration-resistant prostate cancer (mCRPC), with the goal of providing a therapeutic option for this advanced disease state. The primary benefit of these treatments is their potential to help control disease progression and support clinical response in patient populations with limited treatment options.

Eligibility and Restrictions for Use

Eligibility for Harpoon is strictly defined by regulatory authorities to exclude populations with specific contraindications. The systemic (oral) form is absolutely prohibited for patients with a known allergy to Ofloxacin or the entire fluoroquinolone class of antibiotics. Use is also contraindicated in individuals with a history of myasthenia gravis, pre-existing tendon disorders related to fluoroquinolones, or conditions that increase the risk of seizures or QT interval prolongation (such as uncorrected hypokalemia). Use is also formally contraindicated during pregnancy and breastfeeding.

Age Group Systemic (Oral) Use Status
Children/Adolescents (<18 years) Contraindicated
Adults (ge 18 years) Approved population

The systemic use is also restricted and requires mandatory dosage adjustment in patients with impaired renal function (creatinine clearance le 50 mL/min). Patients receiving concomitant corticosteroids or those who are organ transplant recipients must use the medicine with caution due to an increased risk of tendon rupture. Older adults are an approved population but must be monitored for age-related decline in kidney function.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Before taking Harpoon, it is important to discuss all current medications and products with a healthcare provider, as several documented interactions can occur. These interactions are generally classified as serious due to the potential for increased toxicity or reduced effectiveness of Harpoon or the co-administered product.


Potential Drug-Drug and Drug-Food Interactions

Interacting Product Category Specific Examples (if listed) Potential Effect
Antiarrhythmics & Antipsychotics Amiodarone, Sotalol, Chlorpromazine, Haloperidol Increased risk of QT prolongation (a serious cardiac rhythm issue).
Xanthines Theophylline, Oxtriphylline Increased effects and potential toxicity of the xanthine drug.
Anticoagulants Warfarin, Aspirin Enhanced effect of the anticoagulant, raising the risk of bleeding.
NSAIDs (Non-Steroidal Anti-Inflammatory Drugs) Ibuprofen, Naproxen Increased risk of Central Nervous System (CNS) stimulation and seizures.
Dairy Products (Food Interaction) Milk, Cheese Reduced absorption of Harpoon, lowering its effectiveness.

Interaction-Related Restrictions

Concurrent use with Antiarrhythmics, Antipsychotics, and NSAIDs is often advised against due to the risks of cardiac events and seizures. Patients should avoid consuming Dairy products concurrently with Harpoon to ensure optimal absorption. The combination with anticoagulants and xanthines requires careful clinical monitoring to adjust dosages and manage increased toxicity risks. Consult official labeling for specific restrictions and management protocols.

Mechanism of Action

The mechanism of action for Harpoon involves two distinct and complementary antimicrobial strategies employed by its active components, leading to the eradication of susceptible microorganisms.


Disruption of Microbial DNA Integrity

This core domain explains how the Ofloxacin component works by specifically targeting and inhibiting bacterial DNA Gyrase and Topoisomerase IV enzymes. This action traps the enzyme-DNA complex, causing irreversible double-strand breaks in the bacterial genome, which halts DNA replication and results in a bactericidal effect.


Targeted Activation in Anaerobic Environments

This domain describes the unique mechanism of Ornidazole, which is dependent on the low-oxygen conditions and nitroreductase enzymes found exclusively in anaerobic pathogens and protozoa. Upon activation, the drug forms highly reactive free radicals that chemically destroy the microorganism's DNA and macromolecules, resulting in protozoacidal and anaerobic bactericidal action.


Complementary Spectrum Expansion

When combined, these two mechanisms operate additively on separate biological targets—aerobic Topoisomerases (Ofloxacin) and anaerobic DNA (Ornidazole)—to cover an expanded spectrum of pathogenic organisms. This physiological complementarity contributes to the elimination of pathogens in polymicrobial contexts.

Dosage and Administration Information

Harpoon is administered according to specific protocols to ensure standardized usage across its available forms. It is supplied as an oral tablet for systemic use and as a sterile solution for targeted topical application to the eyes (ophthalmic) or ears (otic).


Dosing and Frequency

For systemic treatment, standard adult regimens typically involve doses ranging from 200 mg to 400 mg, commonly administered once or twice daily. The oral tablet may be taken with or without food, swallowed whole with sufficient water. The total treatment course is generally short-term, typically spanning 7 to 14 days, to complete the course.

Topical administration follows specific procedural requirements. The otic solution requires warming the container by holding the bottle in the hand before use, and the patient must maintain a specific head position during and for a period after instillation to facilitate proper delivery. The ophthalmic solution often starts with a high frequency (e.g., every two hours) that tapers to four times daily. For all uses, the dosage schedule, whether a fixed daily frequency or a tapering regimen, must be strictly followed.

Population-specific adjustments are utilized for patients with renal impairment. A reduction in the daily dose or an extension of the interval between doses is used to prevent accumulation, while doses should not be doubled to compensate for a missed administration.

Recent Clinical Evidence

Overview of Clinical Studies

Studies have examined whether the use of the study compound alongside D2 is associated with an improvement in C1 symptoms. A Phase 3 Randomized Controlled Trial (RCT) explored the outcomes associated with this combination, focusing on changes in the severity of C1.

A number of studies have evaluated the outcomes associated with this treatment option. Research has explored the effects associated with the compound's use on symptoms related to C2, including pain and inflammation.

X3 has been reported as a common side effect in trials. Participants in studies experienced it as a temporary effect. Studies specifically excluded participants with existing C3 conditions.


Studies on C1 Outcomes

The initial Phase 2 trial focused on the X1 monotherapy. The study compared outcomes of the drug to those of other standard treatments. The Phase 2 study reported changes in C1 symptom scores among participants receiving the study compound. The Phase 3 trial expanded on this by evaluating the drug when co-administered with D2.

Investigating Acute C4

Studies evaluated the speed of symptom resolution for acute C4 flare-ups among participants using the drug. Research showed variability in the time to resolution. Outcomes were recorded across various participant demographics to assess consistency.


Reported Side Effects

Across the trials reviewed, the most frequently reported side effects included X3, X5, and X6.

X3 was a common finding, typically resolving within the first three weeks of study participation. X4 was reported as a serious side effect in a minority of trial participants.

Combination Therapy Research

Some research explored co-administration with D3 to assess if a difference in outcomes was observed. This preliminary research compared the effects of the compound alone versus the compound with D3 in a small cohort of participants with C2. The research used a small cohort, and findings are considered preliminary.

Frequently Asked Questions (FAQ)

Common questions about Harpoon (FAQ)


Q: How quickly does Harpoon start working after you take it?

A: Official information regarding the active component, Ofloxacin, indicates that it is absorbed quickly. Maximum concentrations of the medicine in the bloodstream are typically reached about one to two hours after an oral dose. This regulatory data indicates the general timeframe for the drug to begin acting throughout the body.


Q: How long does Harpoon stay in your system?

A: The half-life of Ofloxacin, the primary ingredient, is approximately 4 to 5 hours in healthy adults. This is the time it takes for half of the drug to be eliminated. According to regulatory data, between 65% and 80% of an oral dose is typically excreted unchanged through the kidneys within 48 hours.


Q: Is Harpoon considered a high-risk medication?

A: Official prescribing information includes serious safety warnings that require careful consideration. These warnings highlight the potential for serious effects, such as tendon rupture and peripheral neuropathy (nerve damage). The presence of these warnings and constraints emphasizes the need for careful use and clinical monitoring.


Q: Does Harpoon interact with birth control pills?

A: Regulatory guidance suggests that the Ofloxacin component of Harpoon is generally not expected to reduce the effectiveness of hormonal contraceptives, unlike certain other antibiotics. However, general patient guidance suggests that all current medications, including hormonal contraceptives, should be reviewed by a healthcare provider.


Q: Is Harpoon available in a generic version?

A: Yes, products containing the active ingredients Ofloxacin and Ornidazole are available as generic alternatives in addition to the brand name Harpoon. This is a common practice once a drug's patent has expired.


Q: Does Harpoon need to be taken with food?

A: Official product labeling states that the oral tablet form of the medicine can be taken with or without food. However, it is explicitly advised that the medicine should not be taken at the same time as dairy products (like milk or cheese), as they can reduce the drug's absorption and lower its effectiveness.


Q: Is it safe to drink alcohol while taking Harpoon?

A: Official warnings advise against the consumption of alcohol. Because Harpoon often contains Ornidazole, the interaction may result in a severe reaction, often called a disulfiram-like reaction, which can include symptoms such as flushing, headache, nausea, and vomiting.


Q: Can children or teenagers use Harpoon?

A: The systemic (oral tablet) form of this medicine is formally contraindicated (prohibited) in children and adolescents under 18 years of age. This restriction is due to concerns about potential harm to developing joints and cartilage. However, the topical forms (eye or ear drops) may be approved for pediatric use, depending on the specific product label.


Q: Are there any long-term effects of taking Harpoon?

A: While the medicine is prescribed for a short duration, regulatory warnings note that some serious adverse effects may persist or develop after the treatment is finished. Specifically, tendon rupture and peripheral neuropathy (nerve damage) may occur during treatment or several months after the final dose. The nerve damage can potentially be irreversible.


Q: How long does a course of Harpoon treatment usually last?

A: The systemic (oral) course of treatment for Harpoon is designed to be short-term, typically prescribed for a duration between 7 to 14 days. The prescribed duration should be adhered to, as the total length of treatment is determined by the specific infection being treated.


Q: Is Harpoon safe to take during pregnancy or while breastfeeding?

A: Regulatory documents state that the use of Harpoon is formally contraindicated (prohibited) during both pregnancy and breastfeeding. This prohibition is due to potential risks of harm to the fetus and the presence of the drug's active ingredients in human breast milk.


Q: Do people gain or lose weight when taking Harpoon?

A: Weight changes are not listed among the common or frequent side effects of Harpoon. However, regulatory documents do mention that severe and rapid changes, such as unusual weight loss or weight gain, have been reported in very rare cases. Any sudden or severe changes in weight should be discussed with a healthcare provider immediately.


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

A: Official prescribing information commonly lists nervous system effects like dizziness and headache as side effects. Excessive tiredness has also been reported. While not listed as common, any unusual or severe fatigue should be reviewed by a healthcare provider.


Q: What is the main benefit of using Harpoon?

A: The primary benefit of Harpoon is to provide a definitive therapeutic intervention for infections. It achieves this by actively killing a broad range of susceptible bacterial pathogens and, in its combination forms, also eradicating certain protozoan pathogens.


Q: Are the side effects of Harpoon permanent?

A: The majority of common side effects, such as nausea and headache, are typically temporary and resolve quickly. However, official warnings specifically highlight that peripheral neuropathy (nerve damage) is a serious side effect that has the potential to become potentially irreversible.


Q: Can Harpoon be crushed or split if it's a pill?

A: No. Official guidance states that the oral tablet form of the medicine must be swallowed whole with sufficient water. It should not be crushed, broken, or chewed. This is because altering the tablet can change the way the drug is released into the body, potentially affecting its safety or effectiveness.


Q: What happens if Harpoon is taken for longer than recommended?

A: Regulatory documents stress the importance of strictly adhering to the prescribed dosage and duration of treatment. Taking the medicine for longer than recommended is considered a form of overdosage, which can lead to a significant worsening of side effects. If this occurs, it is important to contact a healthcare provider for guidance.


Q: Are there any lifestyle changes that make Harpoon more effective?

A: Official product information for the oral form does not mandate specific lifestyle changes for effectiveness, beyond avoiding concurrent dairy product intake. However, for certain topical applications, the label may include general advice, such as maintaining good hygiene, to aid the effectiveness of the treatment.


Q: Does Harpoon affect blood pressure or heart rate?

A: Yes, it can. The medicine is associated with a risk of a serious cardiac rhythm issue called QT prolongation. This effect can potentially lead to an irregular heartbeat. Patients with existing heart conditions or who take interacting medicines must be monitored and use the medicine with caution.

How should Harpoon be stored and disposed of?

The official storage and disposal requirements for Harpoon (Ofloxacin) must be strictly followed to ensure product integrity and public safety.

Storage Conditions

  • Temperature: Store at Controlled Room Temperature, typically 20 C to 25 C (68 F to 77 F), with permitted excursions up to 30 C (86 F) [Source: FDA Prescribing Information].
  • Protection: The medicine must be kept in its closed container, protected from freezing, direct light, excess heat, and moisture [Source: NIH MedlinePlus/Regulatory Documents].
  • Child Safety: The product must be stored out of the sight and reach of children [Source: FDA/EMA Labeling].

Disposal Instructions

Unused or expired medicine should be returned via a drug take-back program or mail-back envelope as the primary method [Source: FDA]. If take-back options are unavailable, the drug must be mixed with an undesirable substance (e.g., used coffee grounds) and sealed in a container before being discarded in the household trash. The medicine must not be flushed down the sink or toilet [Source: FDA Drug Disposal Guidelines].

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

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