Seglor

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Seglor

Method of action: Analgesic, Vasodilator

Treatment option: Pain, Hypotension, Headache, Migraine

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 Seglor

Quick Facts

Property Description
Active Ingredient Dihydroergotamine mesylate
Pharmacological Class Ergot Alkaloid Derivative, Vasoconstrictor
Primary Forms Injection solution, Nasal spray, Oral capsule (modified-release)
Origin/Type Semi-synthetic (derived from ergotamine)
General Purpose Acute (Abortive) treatment of severe headache episodes

Seglor: Definition and Chemical Identity

Seglor is a prescription-only medicine containing the active ingredient Dihydroergotamine mesylate (DHE), which is the compound utilized for acute, severe headaches. The active substance is chemically defined as a semi-synthetic derivative of the natural ergot alkaloid, ergotamine, making it a distinct member of the Ergot Alkaloid Derivative class. The Dihydroergotamine compound, in use since the 1940s, is one of the oldest specific antimigraine agents and is characterized as a single-ingredient product.

Classification and Available Forms

Functionally, Seglor is classified as an Antimigraine agent and Vasoconstrictor. The non-selective affinity of Dihydroergotamine for multiple monoamine receptors, including 5-HT1B, 5-HT1D, and alpha-adrenergic receptors, differentiates it from the later-developed triptan class. Due to the active ingredient’s very poor oral absorption, DHE is typically supplied in dosage forms that bypass the digestive system for reliable delivery. These forms primarily include an injection solution (for parenteral routes) and a nasal spray (intranasal route), though a unique modified-release oral capsule formulation has been historically associated with the Seglor brand in some markets.

General Therapeutic Purpose

Seglor's fundamental role is to serve exclusively as an acute, abortive treatment, designed to stop an established, severe headache episode after its onset. The drug exerts its therapeutic effect through a dual mechanism: causing constriction of intracranial blood vessels and inhibiting the release of pro-inflammatory neuropeptides from the trigeminal nerves. Pharmacologically, DHE is recognized for providing sustained relief and preventing the headache attack from quickly recurring, which is a key clinical benefit. Its therapeutic function is limited to episodic intervention, not the long-term prevention of future headache attacks.

What side effects are possible with Seglor?

Possible Side Effects and Safety Information for Seglor

Seglor, which contains Dihydroergotamine mesylate, has an official safety profile categorized by regulatory agencies based on its vasoconstrictive properties. Adverse reactions are grouped by the physiological system affected and their reported frequency in clinical use.

Adverse Reaction Classifications

Classification Examples of Reactions
Very Common (ge 10%) Rhinitis (primarily with nasal spray)
Common (1% to 10%) Nausea, vomiting, dizziness, somnolence, pharyngitis
System-Organ Classes Gastrointestinal, Nervous System, Respiratory, Vascular

Serious Safety Constraints and Risks

Official regulatory documents emphasize the risk of serious adverse reactions related to vasospasm, which can lead to myocardial infarction (heart attack), stroke, or peripheral ischemia. For the injectable form, prolonged daily use is associated with the risk of fibrotic complications, such as pleural and retroperitoneal fibrosis.

Seglor is contraindicated in several specific situations, including: pregnancy and lactation; patients with severe hepatic or renal impairment; and individuals with underlying uncontrolled hypertension or ischemic heart disease. It is also strictly contraindicated when taken alongside potent CYP3A4 inhibitors, as this combination greatly increases the risk of life-threatening vasospasm. Frequent use of Seglor or other acute headache medicines can lead to Medication Overuse Headache.

Overdose and Emergency Response

Overdose and When to Seek Help

The official regulatory documentation identifies the overdose syndrome for Dihydroergotamine mesylate, known as ergotism, as resulting from intense, systemic vasoconstriction. Documented clinical manifestations primarily involve the peripheral vascular system, presenting as numbness, tingling, and pain in the fingers and toes, often accompanied by bluish discoloration (cyanosis) or muscle cramps in the limbs. Gastrointestinal symptoms such as severe nausea, vomiting, and abdominal pain are also commonly noted. Central nervous system effects can include confusion, dizziness, headache, and in severe cases, seizures and coma.

Due to the fundamental mechanism of vasospasm, overdose carries the risk of life-threatening ischemic complications. These documented outcomes include peripheral ischemia, acute myocardial infarction, cerebral ischemia, stroke, and lethal disturbances of cardiac rhythm. Prolonged, severe ischemia of the extremities may ultimately result in gangrene.

Regulators mandate that patients immediately seek medical attention and discontinue the drug at the first sign of vasoconstriction, such as coldness or pain in the extremities. Urgent hospitalization is required if collapse, breathing difficulty, or seizures occur. Treatment is supportive and symptomatic; no specific antidote is known. Dihydroergotamine is contraindicated in patients with severely impaired hepatic or renal function, as these conditions increase the risk of elevated drug levels and toxicity.

Therapeutic Uses of Seglor

What Seglor Treats: Main Uses and Benefits

Seglor is commonly used as a relevant acute therapy for intervening in debilitating episodes of migraine and cluster headache. This medication is relevant in conditions involving severe, throbbing head pain and associated symptoms such as nausea, vomiting, and heightened sensitivity to light and sound. The primary therapeutic benefit is providing supportive symptomatic relief to ease the overall symptom burden of the attack once it has begun.

This medication is commonly applied in clinical settings that involve acute or unstable symptom patterns, particularly those that are treatment-resistant. It is also relevant for managing status migrainosus, a prolonged and unrelenting type of acute episode. The use of Seglor in these challenging situations helps to maintain a sense of stability when symptoms are more noticeable.

Quick Fact: Relief for Severe Episodic Pain

Characteristic Description
Primary Indication Acute migraine headache, cluster headache
Symptom Target Severe pain, nausea, light and sound sensitivity
Main Clinical Use Rescue therapy for treatment-resistant attacks
Core Benefit Supportive symptomatic relief, sustained effect

Regulatory References

  1. NIH MedlinePlus overview

Eligibility and Restrictions for Use

Eligibility Map: Who can and cannot use Seglor (Ertugliflozin/Metformin)

This medicine is authorized exclusively for use in adults with Type 2 diabetes mellitus as an adjunct to diet and exercise. Official regulatory documents define clear populations who must not use this medication.


Contraindicated Populations (Must NOT Use)

  • Severe Renal Impairment: Patients with severe kidney failure (eGFR less than 30 mL/ min/1.73 m^2), end-stage renal disease (ESRD), or those undergoing dialysis.
  • Metabolic Acidosis: Any patient with acute or chronic metabolic acidosis, including diabetic ketoacidosis.
  • Hypersensitivity: Patients with a known severe allergic reaction to ertugliflozin, metformin, or any component of the tablet.

Restricted or Not Recommended Use

  • Type 1 Diabetes: The medicine is not recommended for improving blood sugar control in patients with Type 1 diabetes.
  • Moderate Renal Impairment: Initiation is not recommended for patients with an eGFR less than 45 mL/ min/1.73 m^2.
  • Hepatic Impairment: Use should be avoided in patients with liver impairment.
  • Pregnancy/Lactation: Use during the second and third trimesters of pregnancy may be associated with fetal harm. Breastfeeding is not recommended.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The regulatory profile for Seglor (Dihydroergotamine mesylate) emphasizes the risk of severe vasoconstrictive toxicity when co-administered with certain medications that affect its clearance or its pharmacodynamic action. The highest level of caution is placed on combinations formally classified as contraindicated in official prescribing information.


Contraindicated Drug–Drug Interactions

The most critical restrictions involve substances that impede the metabolic breakdown of Dihydroergotamine via the CYP3A4 enzyme system, which significantly increases the drug's exposure (plasma concentration).

Category Interacting Entity / Classification Official Regulatory Outcome / Restriction
Pharmacokinetic Risk Potent CYP3A4 Inhibitors (e.g., Macrolide Antibiotics, Azole Antifungals, Protease Inhibitors) Co-administration is contraindicated due to risk of life-threatening peripheral ischemia and vasospasm.
Pharmacodynamic Risk Other 5-HT1 Agonists (Triptans) or Ergotamine-containing Medications Co-administration is contraindicated due to risk of additive vasoconstrictor effects.

Additional Interaction Restrictions

For other 5-HT1 agonists and ergotamine-type medications, official labeling mandates a timing-based interaction rule: these drugs must not be used within 24 hours of Dihydroergotamine. Additionally, Grapefruit juice is documented to potentially increase drug blood levels, and nicotine use may enhance vasoconstriction. The use of Seglor is also contraindicated in individuals with severe hepatic or severe renal impairment, as high clearance reliance in these organs increases the risk of drug accumulation and toxicity.

Mechanism of Action

The physiological action of Dihydroergotamine (DHE) (Seglor) is achieved through a dual-action mechanism that modulates the trigeminovascular system by targeting key monoamine receptors. This dual action contributes to the interruption of the underlying acute physiological processes.

Modulating Cranial Vascular Tone

This domain covers DHE's role as an agonist at the 5-HT 1B receptors located on the walls of extracerebral blood vessels. Activation of these receptors initiates a cellular cascade that causes the constriction of pathologically dilated cranial vessels, thereby modulating the abnormal vascular tone.

Inhibiting Neurogenic Signaling

This domain focuses on DHE's agonist activity at the 5-HT 1D receptors found on peripheral nerve endings and within the central trigeminal pathways. This interaction inhibits the release of pro-inflammatory neuropeptides like CGRP, thus restricting the initiation and propagation of neurogenic inflammation and suppressing the transmission of nociceptive signals centrally.

Mechanistic Constraints from Non-Selectivity

This domain highlights the drug's inherent non-selective agonism, which includes activity at alpha-adrenergic and other monoamine receptors alongside the therapeutic 5-HT1 targets. This broad interaction profile dictates the systemic physiological effects of the molecule and functionally imposes systemic constraints on the level of receptor occupancy that can be achieved.

Dosage and Administration Information

Seglor administration is strictly governed by a non-chronic, intermittent use protocol, designed only for the acute intervention of severe headache episodes. The medication is officially available for delivery via parenteral routes—including Intramuscular (IM), Subcutaneous (SC), and supervised Intravenous (IV)—as well as the intranasal route as a metered spray or powder. These diverse routes circumvent the active ingredient’s low oral absorption, with the choice of method dictating the precise dosing schedule.

Administration is independent of meal timing and follows precise numerical limits. For parenteral administration (IM/SC), a typical starting dose is 1 mg, with potential for a subsequent dose after a mandatory interval of 1 hour. Crucially, total use is strictly capped by a maximum weekly dosage of 6 mg for injection. Intranasal products likewise feature fixed 24-hour and 7-day maximum limits that define the boundaries of acute use.

Procedural adherence is essential to correct use. This includes priming the nasal spray device prior to the initial administration and the required rotation of injection sites for self-administered parenteral doses. Furthermore, official labeling restricts administration based on pre-existing conditions, defining the medicine as contraindicated in cases of severe hepatic or renal impairment. Safety and effectiveness have not been established for use in individuals under 18 years of age.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Seglor

The research evidence for Seglor (dihydroergotamine mesylate) has been compiled from controlled trials and observational studies, focusing on its use in acute, severe headaches. The research describes the types of studies that examined short-term changes in symptoms and the broader evidence landscape.


Evidence for Acute Treatment of Migraine Headache

The primary evidence relies on short-term, randomized, double-blind, placebo-controlled trials (RCTs). These studies were applied in research contexts involving fluctuating symptoms in adults with moderate to severe migraine. Research examined outcomes related to physical discomfort, such as the proportion of participants who reported pain relief or pain freedom within two hours. Studies also monitored the maintenance of pain freedom (sustained response) over 24 to 48 hours post-treatment. Findings describe patterns observed in these studies regarding pain and associated symptom scores.


Research for Severe and Complex Headaches

Research for Seglor in conditions involving periods of heightened symptoms, such as protracted or treatment-resistant migraine (status migrainosus) and acute cluster headache, was evaluated in specialized settings. This evidence base consists mostly of open-label studies, retrospective reviews, and case series. These studies examined patient-reported experiences related to the termination of a prolonged headache episode and tracked the effect on attack intensity. Evidence remains limited for both conditions compared to standard episodic migraine trials, as large-scale, controlled comparisons are often not available.


Evidence Gaps and Limitations

While efficacy has been measured in the overall adult migraine population, subgroup findings are uncertain regarding how treatment response may vary across ages or specific comorbidities. Furthermore, there is limited information for long-term outcomes when comparing Seglor directly against newer acute migraine treatments in multi-year randomized trials. Studies focus on group averages and patterns, and research does not determine whether an individual will respond similarly.

Frequently Asked Questions (FAQ)

Common questions about Seglor (FAQ)

Q: Is Seglor the same kind of medicine as [similar competing drug name]?

A: Official regulatory documents indicate that Seglor's active ingredient, Dihydroergotamine, belongs to the Ergot Alkaloid class. This class of medication has a specific non-selective receptor binding profile that distinguishes it from other acute migraine treatments like the Triptans.

Q: How does Seglor differ from other treatments for the same condition?

A: Official regulatory documents describe the function of the drug as involving the constriction of certain blood vessels and the restriction of pro-inflammatory nerve signals. This two-part action distinguishes it from other acute migraine agents.

Q: Can Seglor be used for health issues other than what is listed on the label?

A: According to official regulatory documents, the approved indications for Seglor are limited to the acute treatment of migraine headaches (with or without aura) and acute cluster headache episodes.

Q: Is Seglor a pain reliever?

A: Seglor is officially classified as an anti-migraine agent and vasoconstrictor, rather than a general pain reliever. However, clinical studies describe efficacy based on the percentage of participants achieving a 'headache response,' which is defined as a reduction in pain severity to mild or no pain.

Q: How long does it typically take before Seglor starts working?

A: Headache response in clinical studies is measured at specific time points, such as two and four hours after administration. This response reflects a reduction in headache severity to a mild level or complete freedom from pain.

Q: Will I feel the effects of Seglor immediately after taking it?

A: Official clinical studies on the medication measure a significant headache response at time points starting at 30 minutes to one hour after administration.

Q: What should I do if I feel like Seglor isn't working for me?

A: The official prescribing information instructs that patients whose headaches do not improve or occur more frequently than the specified limits should consult with their healthcare professional.

Q: Are there any specific foods or drinks that should be avoided while taking Seglor?

A: Official regulatory documents note that grapefruit juice consumption may increase drug levels in the body and should be limited. Nicotine use is also noted to enhance vasoconstriction.

Q: What is the shelf life of Seglor once I get it from the pharmacy?

A: According to the official product information, Seglor must be stored at room temperature, typically between 20 C to 25 C. It is strictly required that the product be kept away from heat, moisture, and direct light, and it must not be refrigerated or frozen.

Q: Is Seglor a branded medicine or a generic one?

A: Seglor is the brand name associated with the active ingredient Dihydroergotamine mesylate. Official information indicates that lower-cost generic versions of Dihydroergotamine are also available.

Q: Does Seglor have any warnings about driving or operating machinery?

A: Yes, official patient advice notes that because common side effects include dizziness and somnolence (drowsiness), patients should avoid driving or operating heavy machinery until they understand how the medication affects them.

Q: Is Seglor a long-acting medicine or a short-acting medicine?

A: The drug is approved for acute, episodic intervention to stop an established headache episode. The active ingredient has a biphasic plasma elimination profile with a terminal half-life of approximately 9 to 10 hours.

Q: Is Seglor safe to take with common vitamins or supplements?

A: Official regulatory information requires caution regarding co-administration with any substance that affects the CYP3A4 enzyme system (a group of enzymes that break down the drug in the body). Taking the drug with such substances can increase Seglor's exposure and raise the risk of serious side effects like vasospasm.

Q: Are the side effects of Seglor generally temporary?

A: According to regulatory reports, the common side effects are generally described as mild, moderate, and temporary. However, the regulatory label warns of a risk of serious, long-term complications, such as fibrosis, linked to chronic daily use.

Q: How often do people experience the more serious side effects of Seglor?

A: Official documents describe the incidence of serious cardiac events as reported, and note that other serious adverse reactions, including stroke and ischemia, have been reported. The full prescribing information contains detailed frequency data.

Q: Can Seglor be taken by older adults or seniors?

A: Safety and effectiveness have not been specifically established for patients over 65 years of age. Official information notes that caution is advised for this population due to the greater likelihood of age-related kidney, liver, or heart conditions.

Q: Is it okay to drink alcohol in moderation while using Seglor?

A: Official warnings note that consuming alcohol while taking this medication may increase the risk of certain side effects, particularly dizziness or fainting spells.

Q: Can Seglor be stopped suddenly, or does it require gradual tapering?

A: Since Seglor is approved only for acute and intermittent use to treat established headache episodes, it is not a chronic medication. Therefore, gradual tapering is generally not necessary when stopping an acute course of treatment.

Q: What should I do if I suspect an interaction between Seglor and another medicine?

A: Official patient information notes that if you experience symptoms potentially related to a serious interaction, such as coldness, numbness, or tingling in the hands or feet, immediate contact with a healthcare provider is recommended.

Q: What type of healthcare professional usually prescribes Seglor?

A: Seglor is designated as a prescription-only medicine with specific dosing and administration protocols. The medication requires a clear diagnosis and instruction from a licensed healthcare provider, such as a primary care doctor or a specialist like a neurologist.

Q: Is Seglor considered a controlled substance?

A: No, according to regulatory classification systems, the active ingredient Dihydroergotamine mesylate is generally considered a non-controlled medication.

Q: Is there any research suggesting Seglor could help with mental health issues?

A: The official research and regulatory approval for Seglor are focused exclusively on its use for the acute treatment of migraine and cluster headaches.

Q: Where can I find the official patient information leaflet for Seglor?

A: The official patient information sheet is typically found printed at the end of the full prescribing information documents. You can find this official documentation publicly available on regulatory websites such as the NIH's DailyMed and the FDA's Drugs@FDA database.

Q: What does 'contraindication' mean when talking about Seglor?

A: In official medical labeling, a contraindication is a condition or factor that absolutely forbids the use of the drug because the risk of harm to the patient is too high. Examples provided in the labeling for Seglor include conditions like pregnancy or having severe, uncontrolled high blood pressure.

Q: Are there specific symptoms that mean I should contact a healthcare provider immediately while on Seglor?

A: Yes, official patient information lists several symptoms that may indicate a serious reaction. These include numbness or tingling in the fingers and toes, severe or sudden chest pain, difficulty speaking, or any sudden, unusually severe headache.

Q: Does Seglor contain gluten or any common allergens?

A: The full regulatory labeling lists all components, including excipients (inactive ingredients). Official warnings specifically note that some forms of the injectable device may contain a natural rubber latex derivative in the needle cover, which is a key allergen.

Q: How can I get an official copy of the Seglor prescribing information?

A: The official prescribing information for the active ingredient Dihydroergotamine is publicly accessible online. You can typically find this document on regulatory agency websites, such as the FDA's Drugs@FDA and the NIH's DailyMed databases.

Q: Is Seglor known to cause dependence or addiction?

A: Official patient labeling states that the medication 'may be habit-forming' and provides strict warnings against increasing the dosage or using the medicine more frequently than prescribed. This is due to the potential for medication overuse headache.

Q: Can I take Seglor if I have a history of [specific condition, e.g., seizures]?

A: The official prescribing information provides a list of serious medical conditions, such as uncontrolled high blood pressure and severe kidney impairment, which are formal contraindications.

Q: What happens if I take more Seglor than intended?

A: Official regulatory documents describe the potential signs of an overdose, which include blurred vision, confusion, and pain, numbness, or a bluish discoloration of the hands and feet.

How should Seglor be stored and disposed of?

Official Storage and Handling Requirements

Seglor (Dihydroergotamine Mesylate) must be stored at room temperature, typically between 20 C to 25 C (68 F to 77 F), with storage below 25 C being mandated by regulatory labeling. It is strictly required that the product be kept away from heat, moisture, and direct light. The medication must not be refrigerated or frozen under any circumstances.

Stability and Disposal Rules

Stability is time-sensitive after opening: the nasal spray must be thrown away after 8 hours once the vial is opened, and the injection vial must be discarded 1 hour after opening. The medicine must be stored in a closed container and kept out of the reach of children. Used injection needles and syringes must be disposed of according to sharps guidelines in a hard, closed container, as Dihydroergotamine is classified as a hazardous drug.

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

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