Meladinine

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Meladinine

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 Meladinine

Property Description
Active Ingredient Methoxsalen (8-methoxypsoralen or 8-MOP)
Forms Tablets, capsules, topical solutions, sterile solution
Pharmacological Class Psoralen, Photosensitizer
Functional Principle Sensitizes cells to UVA light (Photochemotherapy)
Origin Naturally occurring (e.g., Ammi majus), also produced synthetically

What Type of Medicine is Meladinine (Methoxsalen)?

Meladinine is a trade name for a prescription medication whose active ingredient is Methoxsalen, which is formally classified as a psoralen and a specialized photosensitizer. The compound is derived from the furocoumarin class of molecules and is also known chemically as 8-methoxypsoralen or 8-MOP. Its status as a photosensitizer means its biological effect is entirely contingent upon external energy; specifically, it requires exposure to long-wave ultraviolet A (UVA) light for activation. This light-dependent activity establishes Methoxsalen as an essential agent in combination treatments known as photochemotherapy.

Composition, Forms, and Origin of Methoxsalen

The Methoxsalen molecule is unique in that it is obtained both as a naturally occurring substance, isolated from plants such as Ammi majus, and through reliable synthetic processes for consistent pharmaceutical use. Meladinine is a single-active-ingredient preparation available in distinct dosage forms tailored to specific clinical requirements. These forms include tablets and soft gelatin capsules for oral (systemic) administration, topical solutions for localized dermal application, and a sterile solution used exclusively for specialized parenteral procedures. The multiple formulations underscore its utility in both dermatological practice and advanced extracorporeal therapies.

High-Level Purpose and Functional Principle

The high-level purpose of Methoxsalen is to sensitize cells to ultraviolet light, acting as the required photoactive agent in PUVA therapy. Upon activation by UVA light, the Methoxsalen molecule binds to the DNA of targeted cells, thus modulating cellular proliferation and growth. This action supports the general benefits of controlling the excessive cell production often associated with chronic skin disorders and promoting the stimulation of residual melanin-producing cells in depigmented areas. This specialized, light-dependent action is recognized for managing conditions related to abnormal cell growth and pigmentation loss when used under professional guidance.

What side effects are possible with Meladinine?

Possible Side Effects and Safety Information

The safety profile of Meladinine (Methoxsalen) is strictly tied to its function as a photosensitizer, and all documented adverse reactions are based on official government regulatory sources.

Adverse Reaction Classification

Side effects are categorized by frequency based on clinical and regulatory data:

Classification Examples of Adverse Reactions (SOC Categories)
Very Common (ge 1/10) Nausea, Pruritus (Itching)
Common (1% to 10%) Vomiting, Hypotension, Transient Fever, Localized Infection (related to specific procedures)

Adverse effects predominantly affect the Skin and Subcutaneous Tissue Disorders and Gastrointestinal Disorders. Other system-organ classes involved include Nervous System Disorders and Ocular Disorders.

Serious and Long-Term Safety Considerations

Official labeling documents highlight serious adverse reactions, particularly those related to chronic exposure. A key concern is the increased risk of cutaneous malignancies, including Squamous Cell Carcinoma (SCC) and Melanoma, which is strongly associated with high cumulative numbers of Methoxsalen/UVA treatments over time. There is also a documented risk of cataract formation if the eyes are not adequately shielded from UVA light during and after administration.

Time-related patterns note that the peak phototoxic skin reaction (erythema or burning) typically occurs 48 hours or later following oral administration, a factor critical to understanding the drug's safety characteristics. Furthermore, regulatory documents state that severe hepatic impairment may prolong the drug's activity, potentially resulting in extended photosensitivity.

Overdose and Emergency Response

Overdose and when to seek help for Meladinine

The regulatory profile for Methoxsalen overdose centers on the immediate and severe consequences of phototoxicity resulting from overdosage or subsequent overexposure to UVA light and sunlight. The focus is on documented manifestations, the risk of serious escalation, and mandatory emergency actions.

Documented Manifestations & Risks Emergency Response & Management
Severe Phototoxicity leading to serious skin burns, pronounced erythema, blistering, and swelling. Seek immediate medical attention upon suspicion of overdose or development of severe symptoms.
The full extent of phototoxic injury may not be evident until 48 to 72 hours post-exposure. Management is primarily symptomatic and supportive, consistent with severe burn care.
Potential for irreversible ocular damage and cataract formation if the eyes are unprotected during light exposure. Antidote Status: No specific pharmacological antidote is documented in official labeling.

Mandated Post-Overdose Actions (24-Hour Requirement)

Following an overdose, regulatory documents mandate strict protective measures for at least 24 hours:

  • Light Avoidance: The patient must be immediately protected by staying out of direct sunlight and all sources of UVA light.
  • Ocular Protection: UVA-absorbing, wrap-around sunglasses must be worn continuously during daylight hours to mitigate ocular risk.

The official overdose structure requires continuous monitoring for the delayed onset of severe injury.

Therapeutic Uses of Meladinine

Quick Fact: Relevant for Symptoms Related to Inflammatory States

What Meladinine Treats: Main Uses and Benefits

Meladinine (Methoxsalen) is a photosensitizing agent used in conjunction with controlled long-wave ultraviolet A (UVA) radiation (PUVA therapy). This combination is commonly used to help with severe, recurrent, and disabling skin conditions.

The primary therapeutic areas involve managing conditions associated with periods of heightened symptoms, specifically psoriasis, cutaneous T-cell lymphoma (CTCL), and idiopathic vitiligo.


Addressing Conditions Characterized by Acute Symptom Patterns

This domain covers conditions which present with systemic or localized discomfort and inflammatory or irritative processes. Meladinine's use is applied in clinical settings that involve acute or unstable symptom patterns. This approach helps ease symptoms related to inflammatory states, which contributes to easing the overall symptom burden.


Managing Conditions Involving Irregular Skin Pigmentation

Meladinine is applied across domains where additional symptomatic support is needed for conditions involving irregular skin pigmentation. Used in phototherapy, it assists with managing symptoms that interfere with daily comfort, offering symptomatic relief and supporting general well-being during symptomatic phases.

Eligibility and Restrictions for Use

Who Can and Cannot Use Meladinine (Methoxsalen)

Official regulatory guidelines define strict population eligibility for Meladinine based on pre-existing conditions, age, and physiological status.

Absolute Contraindications

Meladinine is formally contraindicated and must not be used by patients with specific pre-existing light-sensitive disorders, including lupus erythematosus, porphyrias (e.g., cutanea tarda), and xeroderma pigmentosum. Absolute non-eligibility also applies to patients with aphakia (absence of the eye lens) and those with a history of melanoma or invasive squamous cell carcinoma. Use is also prohibited in cases of known hypersensitivity to psoralens.

Eligibility by Age and Condition

Meladinine is approved for use in adults with severe, recalcitrant psoriasis and cutaneous T-cell lymphoma (CTCL), and in individuals 12 years of age and over for vitiligo. However, safety and efficacy are not established for the injectable solution in the general pediatric population. The medicine is generally not recommended or contraindicated during pregnancy and lactation. Furthermore, use in patients with renal or hepatic impairment is often cited as not clinically established by regulators, requiring caution.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official regulatory documents define the interaction profile of Methoxsalen (Meladinine) based on two primary mechanisms: pharmacokinetic inhibition and additive pharmacodynamic effects. The information below is based strictly on governmental prescribing labels.

Interaction Classifications

Property Description
Interaction Severity Includes combinations classified as Contraindicated (e.g., Fezolinetant) and others requiring strong clinical caution or avoidance.
Regulatory Basis Information derived from official regulatory documents (e.g., FDA, NIH DailyMed).

Documented Interaction Patterns

Methoxsalen is officially classified as an inhibitor of the hepatic enzyme CYP1A2. This classification indicates that co-administration may increase the systemic exposure and effects of other medicines cleared by this pathway, including Melatonin, Pirfenidone, and Bendamustine.

The drug is associated with a risk of additive photosensitization when co-administered with other known photosensitizing agents, such as specific systemic or topical Tetracyclines, Thiazides (diuretics), or Phenothiazines. This additive pharmacodynamic risk also applies to the ingestion or contact with psoralen-containing foods, including Limes, Celery, Figs, and Parsnips, and herbal products like St. John’s Wort.

Mechanism of Action

Photochemical Activation and DNA Damage

The mechanism of Meladinine (Methoxsalen) is entirely contingent upon its role as a photosensitizer, requiring activation by UVA light. This energy enables the drug to form stable, irreversible covalent cross-links with the DNA of targeted cells, specifically binding to pyrimidine bases. This initial molecular action physically prevents the cell from completing the utilization of its genetic material.


Inhibition of Cell Proliferation

The resulting damage to the DNA structure forces hyperproliferative cells, such as epidermal keratinocytes and pathogenic T-lymphocytes, into a standstill at the G1/S phase of the cell cycle. This irreparable genetic injury triggers the apoptosis signaling pathway, leading to the controlled clearance of excess cells. This cascade constitutes the main physiological consequence, resulting in the reduction of excessive cellular proliferation and affecting T-lymphocyte activity.


Time-Dependent Physiological Repair

The drug's mechanism initiates secondary, time-dependent physiological effects as the tissue responds to the phototoxic injury. This includes the stimulation of residual melanocytes to enhance melanin synthesis, which affects the production of pigment. The maximal biological consequence of this mechanism is delayed, typically peaking 48 to 72 hours after UVA exposure, reflecting the time required for the biological cascade of damage and repair to culminate.

Dosage and Administration Information

How Meladinine is Used: Official Administration Guidelines

Methoxsalen (Meladinine) administration is a multi-step process strictly coordinated with ultraviolet A (UVA) light exposure, a treatment method referred to as photochemotherapy or PUVA. Official use is defined by three distinct routes and corresponding regimens.

Administration Routes and Forms

The medicine is available in forms for oral (systemic), topical (localized), and extracorporeal use. The sterile solution form is for the specialized extracorporeal photopheresis procedure and must not be injected directly into the patient; it is administered into the photoactivation system.

Usage Feature Official Instruction Summary
Dosing Timing Oral dose is taken 1.5 to 4 hours prior to the scheduled UVA exposure, depending on the specific formulation, to ensure proper light activation.
Intake Condition Oral forms must be consumed with low-fat food or milk to aid absorption.
Frequency Pattern Treatment is generally intermittent, typically two or three times per week, with a required minimum interval of 48 hours between successive treatments for systemic PUVA.
Dosing Regimens Oral dosing for psoriasis is weight-based, ranging from 10 mg to 70 mg. Dosing for extracorporeal therapy is calculated per treatment volume of collected cells, not patient weight.

This structured approach dictates that Methoxsalen administration is inherently time-critical, requiring precise scheduling and specialist supervision. Treatment protocols for conditions like Cutaneous T-Cell Lymphoma involve strict cyclic regimens, such as treatment on two consecutive days followed by a four-week interval, for a defined number of treatment cycles.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Meladinine

Methoxsalen was studied for its use in photochemotherapy (PUVA) in conjunction with UVA light. The research available explores its application across three key conditions, with studies designed to monitor changes and outcomes over defined time intervals.


Evidence for Use in Severe, Recalcitrant Psoriasis

Research has explored the effects of Methoxsalen photochemotherapy in adults with chronic, severe psoriasis that was unresponsive to other therapies. Researchers examined the rate of psoriatic lesion clearance and the evaluation of whether a clinical clearing state was recorded, which are outcomes linked to inflammatory or irritative states. Studies monitored patterns where high measurements of lesion clearing were observed in the studied populations. Trial reports also monitored the duration that patients were tracked after reaching the point where a clinical clearing state was recorded following the initial treatment phase.


Evidence for Repigmentation in Idiopathic Vitiligo

Systematic reviews and smaller clinical trials monitored the frequency of recorded repigmentation measurements in affected skin areas. Systematic reviews summarizing patient series reported patterns where over half of the participants in reviewed studies recorded high measurements of pigment change. However, findings were mixed, and many reports described the observed clinical pattern as highly variable and unpredictable across different individuals. Research highlights that repigmentation measurements varied depending on the area of the body studied; certain areas such as the hands and feet were observed to show little to no measured change.


Limitations and Research Gaps

Generalizability of the evidence derived from single-arm trials for Cutaneous T-cell Lymphoma (CTCL) is limited, as the research focuses exclusively on a highly specific and treatment-resistant patient group. Furthermore, data for younger children remain insufficient in the published clinical literature. Research limitations exist where follow-up durations were limited in specific trials, which may impact the ability to fully assess the persistence of the measured changes. Findings describe group patterns, and research does not determine whether an individual will respond similarly.

Key Studies & References

  1. Topical TCA and Methoxsalen Not Clinically Effective for Acral Vitiligo (Cited: Vitiligo limitation—acral resistance)
  2. THERAKOS® Photopheresis Clinical Profile | CTCL Treatment Efficacy (Cited: CTCL outcomes/Response timing)

Frequently Asked Questions (FAQ)

Common questions about Meladinine (FAQ)


Q: Is it normal to feel nauseous after taking the Meladinine pill?

According to official product information, nausea is a common adverse reaction for patients taking the oral form of Meladinine. Regulatory data indicates this side effect is reported to occur in approximately 10% of patients.


Q: Are there ways to help reduce the feeling of nausea from Meladinine?

Regulatory information describes the oral form being consumed with milk or low-fat food as an intake condition. This condition is noted to aid in absorption and may help to minimize or avoid the feeling of nausea.


Q: How is Meladinine different from a regular sun tanning pill?

Meladinine is formally classified as a psoralen, which is a specialized photosensitizer. Its functional principle is to aid in photochemotherapy for specific approved skin conditions, requiring UVA light activation to bind to cellular DNA.


Q: Can Meladinine be used without any light exposure?

The drug's therapeutic action is entirely contingent upon its activation by ultraviolet A (UVA) light. Without the required light exposure, Meladinine cannot engage in its core mechanism of binding to cell DNA to produce its intended biological effect.


Q: Can using Meladinine lead to premature aging or wrinkling of the skin?

Official regulatory documents report that prolonged therapy with Meladinine may result in premature aging of the skin. This effect is described as permanent and is comparable to the long-term effects of excessive sun exposure.


Q: Is there a long-term risk to the kidneys from Meladinine use?

Safety and efficacy in patients with severe kidney problems (renal impairment) are not clinically established in the official prescribing information. The regulatory labeling indicates that pre-existing kidney problems should be communicated to the healthcare provider.


Q: Can Meladinine cause stomach pain or discomfort?

While nausea and vomiting are the most common gastrointestinal side effects listed, official labeling documents also include general gastrointestinal disturbances and stomach upset in the reported adverse reactions.


Q: How long after taking the oral capsule is the skin most sensitive to light?

The time of maximum photosensitivity varies depending on the specific capsule formulation used. Official information generally indicates that the skin is most sensitive to light between 1.5 and 4 hours after taking the oral dose.


Q: Is there a maximum number of treatments recommended for Meladinine therapy?

Official documents warn that the risk of serious long-term side effects, such as skin cancer, is strongly associated with the high cumulative number of Meladinine/UVA treatments administered over time. The cumulative dose is considered a critical safety factor.


Q: Does Meladinine require a change in how I use soaps or other skincare products?

Official guidance states that consultation with the doctor is necessary before using any other products on the skin while undergoing Meladinine treatment. This precaution applies to common items like soaps and various over-the-counter skincare products.


Q: How quickly do patients typically see results when using Meladinine for vitiligo?

Studies and patient information sources indicate that it may take an average of six to eight weeks before a patient may observe a noticeable improvement or change in the treated skin condition.


Q: What is the expected time frame to see improvement in psoriasis with Meladinine?

Patient information sources indicate that it may take approximately six to eight weeks before a noticeable improvement or change in the psoriatic condition may be observed.


Q: Is Meladinine treatment considered a permanent solution for skin conditions?

Research evidence on the long-term persistence of recorded changes is mixed. Official documents describe the need for continuous monitoring and note that follow-up durations were limited in some trials, impacting the ability to fully assess the long-term status of the condition.


Q: What areas of the body tend to respond best to Meladinine treatment?

Research summarized in regulatory-linked documents indicates that treatment effectiveness can vary significantly across different parts of the body. For example, areas such as the hands and feet were observed to show little to no measurable change.


Q: What types of other medications might increase the risk of side effects with Meladinine?

The risk of photosensitivity and other side effects is increased when Meladinine is co-administered with other known photosensitizing agents. This classification includes specific antibiotics like tetracyclines, certain diuretic medications, or some psychotropic medications.


Q: Why might a doctor choose to use the topical form of Meladinine instead of the oral capsule?

The topical form is typically used for localized treatments. Regulatory rationale indicates that this route may be chosen by a professional to reduce systemic exposure to the drug, which may consequently minimize systemic side effects such as gastrointestinal upset.


Q: Is there a risk of interaction between Meladinine and alcohol consumption?

Regulatory resources cite that a potential interaction with alcohol has been noted in the drug’s official profile. The presence of this warning suggests the need for caution regarding alcohol intake during therapy.

How should Meladinine be stored and disposed of?

How to Store and Dispose of Meladinine (Methoxsalen)

Meladinine must be stored at controlled room temperature, specifically between 20 and 25 C (68 to 77 F), in a tightly closed container. It is mandatory to keep it from freezing and protect it from heat, moisture, and direct light.

Child Safety and Disposal

The medicine must always be stored out of the reach of children.

Unused or expired Meladinine should be disposed of using a local drug take-back program or by following the federal guidelines for household trash disposal. This involves mixing the medication with an undesirable substance like coffee grounds and securing the mixture in a sealed container. Do not flush Meladinine unless the official labeling explicitly instructs it.

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

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