Naratriptan for Migraine: Benefits, Dosage, and Side Effects

Overview:

Naratriptan belongs to the selective serotonin receptor agonist class of drugs. It narrows the brain's blood vessels and blocks pain signals from reaching it, so it is indicated for sudden migraine attacks in adults. Additionally, it can stop the release of substances that result in migraine symptoms, such as pain and nausea. Moreover, the FDA approved it in 1988.

Multiple pharmaceutical companies worldwide produce generic versions of Naratriptan, especially after its original patent expired in 2010.

Naratriptan Dosage and Administration

1. Route of Administration: By mouth.

2. Dosage Strengths: 1 mg and 2.5 mg tablets.

3. Dosage Forms:

• 1 mg Tablets: White, D-shaped, film-coated tablets debossed with GX CE3.

• 2.5 mg Tablets: Green, D-shaped, film-coated, debossed with GX CE5.

The recommended dosage may be either 1 mg or 2.5 mg, which can be repeated after four hours if the initial dose is not completely effective. The maximum dose that may be consumed in a day is 5 mg.

Administration Instructions-

• Take Naratriptan only as prescribed by the doctor.

• Naratriptan may be taken with or without food, but it needs to be swallowed with water.

• Tablets must be swallowed whole and not crushed, chewed, or split.

For Patients:

How Does Naratriptan Work?

Migraines are thought to result from the dilation of the blood vessels around the brain or the release of sensory neuropeptides. Naratriptan binds to the 5-HT1B/1D receptors present in the blood vessels around the brain and acts as an agonist at these receptors. It also acts as an agonist to the sensory nerves of the trigeminal system. The agonist effects of Naratriptan result in the constriction of the cranial blood vessels and inhibition of the release of sensory neuropeptides, thereby stopping migraine.

5-HT Receptors (5-hydroxytryptamine Receptors): 5-HT receptors, also known as serotonin receptors, are essentially a group of receptors that couple with G protein (G protein-coupled receptors) and mediate neurotransmission of excitatory and inhibitory impulses. They are present in the central and peripheral nervous systems.

The 5-HT1B receptor is a protein found in humans and a subtype of the 5-HT receptors. The HTR1B gene encodes it. It affects neurotransmission and vascular effects such as vasoconstriction in the brain and lungs.

5-HT1D receptor or HTR1D receptor is a protein encoded by the HTR1D gene. Its actions on the central nervous system lead to anxiety and locomotor changes. It also causes blood vessel constriction in the brain.

Sensory Neuropeptides: Sensory neuropeptides are released from sensory nerves that innervate blood vessels. They affect the activities of inflammatory cells and have a role in cardiovascular disease.

What Are the Uses of Naratriptan?

Naratriptan is used in the treatment of acute migraine in adults (with or without aura).

Limitations:

It cannot be used as a preventive medicine.

It should also not be used to manage cluster headaches.

Contraindications:

• Allergic to Naratriptan.

• Patients with ischemic coronary artery disease or coronary vasospasm.

• Patients with a history of stroke.

• Patients who have had hemiplegic or basilar migraine episodes are vulnerable to strokes.

• Uncontrolled hypertension patients.

• Patients suffering from peripheral vascular disease.

• Patients with ischemic bowel disease.

• Patients who have already used an ergot type or ergotamine-containing medication or a 5HT-agonist in the past 24 hours.

• Patients with severe renal impairment.

• Patients with severe hepatic impairment.

Warnings and Precautions:

• Myocardial Ischemia or Infarction: Patients with cardiovascular risk factors, including those with Prinzmetal’s angina, should undergo cardiac evaluation and be treated cautiously.

• Arrhythmias: If arrhythmia occurs in a patient upon administration of Naratriptan, the drug should be discontinued immediately.

• Cerebrovascular Conditions: If a hemorrhage (cerebral or subarachnoid hemorrhage) or stroke occurs, the medicine should be immediately discontinued.

• Pressure of the Chest, Throat, Neck, Jaw: If the patient experiences pain, tightness, heaviness, or pressure in the chest, throat, neck, or jaw, it is usually not serious and unrelated to cardiovascular illness. However, if they are at high risk for coronary artery disease, they should be evaluated for it.

• Gastrointestinal Symptoms: If the blood supply to the gastrointestinal tract is cut off or blocked (gastrointestinal ischemia) or the patient experiences localized or diffuse blood vessel constriction in the peripheral regions (peripheral vasospastic reactions), the medicine should be discontinued.

• Serotonin Syndrome: Serotonin syndrome is a severe drug reaction caused by a high build-up of serotonin in the body. If this reaction occurs in a patient, Naratriptan should be stopped.

• Medication Overuse Headache: Also known as rebound headaches, these headaches may occur on long-term use of drugs such as migraine medication (including Naratriptan). If such headaches occur, the patient may require detoxification.

Why Is Naratriptan Prescribed for Migraine?

Naratriptan helps treat migraine symptoms, including throbbing headaches, nausea, and sensitivity to light or sound. This drug works in the following ways:

• It narrows the blood vessels around the brain.

• It blocks the transmission of pain signals to the brain.

• It stops the release of substances that contribute to migraine symptoms like pain and nausea.

• Naratriptan should be taken as soon as you sense that a migraine headache is beginning.

Tips for Maximizing the Effectiveness of Naratriptan

• Take Naratriptan in the manner and dosage strength prescribed by your doctor. The maximum recommended dosage is 5 mg per day.

• Maintain a record of when and how often you get headaches and when you take Naratriptan so your physician knows whether the drug is effective for you.

• If you take too many Naratriptan tablets, you may end up suffering from medication overuse headaches, in which case you may be required to stop taking the drug.

• Practice yoga and relaxing exercises to maximize the effectiveness of Naratriptan.

What Should You Discuss With Your Doctor Before Beginning Naratriptan Therapy?

Before starting this medication, inform the doctor if you are taking any other medicines and if you have any health conditions. Give all the details, like breastfeeding or being pregnant.

1. Medical History: Inform the doctor if you suffer from:

• Heart or kidney-related issues

• Liver problems.

• Diabetes.

• Hypertension or high blood pressure.

• High cholesterol levels.

• Weight issues (being overweight).

• Obesity.

Apart from these, let your doctor know if you are a smoker.

2. Drug History: Inform your doctor of all the prescription and over-the-counter medications you are taking, as well as any herbal supplements and vitamins. The medications you should be particularly wary of are antidepressant drugs. Let your doctor know if you are taking antidepressants.

3. Pregnancy: If you are pregnant or plan on getting pregnant, tell the doctor about it, as it is possible that Naratriptan can cause fetal harm.

4. Lactation: If you are breastfeeding or plan to do so soon, inform your doctor. The possible presence of Naratriptan in breast milk is unclear, so approach your doctor for information on how best to feed your baby while on Naratriptan.

Is Naratriptan Safe?

While Naratriptan is typically safe when taken and consumed as prescribed, there may be a few rare cases where patients experience side effects similar to heart conditions. These include pain, tightness, or heaviness in the chest, jaw, neck, and throat. However, these are not serious and are usually unrelated to heart conditions.

In addition, overuse may lead to headaches, so taking only the prescribed amount is essential.

What Are the Benefits of Naratriptan for Migraine Relief?

A key advantage of Naratriptan rests in its ability to efficiently decrease migraine symptoms that include severe headache pain along with nausea and sensitivity to light and sound. Naratriptan works to decrease brain migraine attacks through its mechanism of narrowing the blood arteries. The medication works well for numerous patients because of its lower number of adverse effects in comparison to other types of triptan medications. Due to its lengthy half-life duration, Naratriptan allows patients to take fewer doses during an attack since it delivers extended relief time. People seeking efficient migraine pain therapy should consider Naratriptan as their medication of choice.

What Side Effects Can You Expect With Naratriptan?

• Serious cardiac events, including myocardial infarction, exist in patients without a coronary artery disease (CAD) history.

• Cardiac rhythm disturbances (arrhythmias) include ventricular tachycardia (increased heart rate in the heart's lower chambers).

• Cerebrovascular events like stroke and hemorrhage may occur.

• Transient blindness, permanent blindness, and partial vision loss have been reported.

• Non-coronary vasospastic reactions such as peripheral and gastrointestinal vascular ischemia.

• Hypertension or increased blood pressure.

• Medication overuse headache.

• Pain or pressure in the chest, throat, neck, or jaw.

• Serotonin syndrome which includes symptoms like hallucinations, agitation, increased heart rate, increased body temperature, nausea, vomiting, and incoordination.

• Excessive allergic reactions (anaphylaxis) or hypersensitivity reactions like angioedema.

Are There Any Dietary Restrictions to Consider When Taking Naratriptan?

• You may take Naratriptan with or without food. There are no other dietary restrictions as such relating to taking the drug.

• The tablet should be swallowed with water.

• Avoid consuming alcohol if you suffer from migraines, it may worsen the headaches.

How Should You Store and Dispose of Naratriptan?

• Store Naratriptan tablets at a controlled room temperature of 20 to 25 degrees Celsius (68 to 77 degrees Fahrenheit).

• Do not store the drug in conditions of extreme heat or moisture.

• Keep the medication away from children and pets, and store it in a container with the lid tightly closed.

What Should You Do in Case of Overdose?

In case of overdose, you may experience a medication overdose headache and need to be detoxified. Your doctor may ask you to stop taking the medication.

In severe cases, call the doctor or the local poison control helpline for information. Alternatively, a visit to the emergency room may become necessary.

What Should You Do If You Miss a Dose?

You can take Naratriptan at four-hour intervals. This drug does not follow a dosing schedule, so you may take a dose when you remember to and ensure that you take the next dose (if necessary) only four hours after the previous one.

Also, remember that the maximum dose you are allowed to take in a day is 5 mg.

What Else Should You Keep in Mind?

Keep track of when and how often you get headaches and when you take your medicines. This can help you determine whether the medicines are working or not.

For Doctors:

Indications:

Naratriptan is mainly indicated for managing sudden or acute attacks of migraine (with or without aura).

Contraindications

• Naratriptan should be taken only if someone has a migraine. If the patient shows no signs of improvement after taking a dose of Naratriptan, an alternative diagnosis should be considered.

• This drug is not indicated for prophylactic purposes.

• Data on the safety and efficacy of Naratriptan for cluster headaches are unavailable. Therefore, it should not be used to treat cluster headaches.

What Is the Pharmacology of Naratriptan?

Mechanism of Action:

Naratriptan binds to human cloned 5-HT1B/1D receptors with a high affinity. Since migraines are thought to result from local cranial vasodilatation and sensory neuropeptide release, Naratriptan's agonist effects are explained. Specifically, Naratriptan has agonist effects at the 5-HT1B/1D receptors on intracranial blood vessels and the sensory nerves of the trigeminal system. This causes the constriction of cranial vessels and inhibition of the release of pro-inflammatory neuropeptides.

Pharmacodynamics:

• Reduction of carotid arterial blood flow with negligible effect on the arterial blood pressure or total peripheral resistance.

• 30 % increase in vascular resistance in the coronary arterial bed.

• Trigeminal nerve activity inhibition.

Pharmacokinetics:

• It is well-absorbed.

• It has 70 % bioavailability when taken orally.

• Peak concentrations reach within hours (2 to 3) after taking a 2.5 mg dose.

• Cmax: In women, it was 50 percent higher after taking 1 mg or 2.5 mg tablets.

• Tmax: Slower during migraine attacks (three to four hours).

• Effect of Food: No effect on the drug pharmacokinetics.

• Volume of Distribution (Steady-State): 170 L.

• Plasma Protein Binding: 28 % to 31 % (concentration range - 50 to 1,000 ng/mL).

• Metabolism: Cytochrome P450 isoenzymes carry out the in vitro metabolization of Naratriptan, which is converted into several inactive metabolites.

• Elimination: Primary urinary elimination (50 % of the dose is recovered unchanged, and 30 % is in the form of metabolites).

• Mean Elimination Half-Life: Six hours.

• Systemic Clearance: 6.6 mL/min/kg.

• Renal Clearance: 220 mL/min.

What Are the Drug Interactions Relating to Naratriptan One Should Be Aware Of?

• Oral Contraceptives: Oral contraceptives cause a 32 % reduction in clearance and a 22 % reduction in the volume of distribution. The concentrations of Naratriptan may thus be a little higher in these cases.

• Monoamine Oxidase: Naratriptan is not an inhibitor of monoamine oxidase (MAO) enzymes.

• P450: Naratriptan inhibits P450 poorly.

What Are the Clinical Trials Related to Naratriptan?

Study design:

Methods: This study included 613 patients. Naratriptan tablets (2.5 mg, 1 mg, 0.25 mg, or 0.1 mg) and, in some cases, a placebo were used.

Primary Outcome Measures: In the study, the severity of migraine, the symptoms associated with it, and the level of clinical disability were recorded after taking the medicines at 30-minute intervals. Safety measures,suchas examining vital signs, monitoring adverse reactions, and undergoing tests, were also considered.

Results:

1. Headache Relief (P < 0.05 Naratriptan 2.5 mg and 1 mg Versus Placebo, 1 mg Versus 0.1 mg, and 2.5 mg Versus 0.1 mg and 0.25 mg) at Four Hours Post Dose:

• Naratriptan 2.5 mg: 60 % of patients experienced relief from the headache.

• Naratriptan 1 mg: 50 % of patients experienced relief from the headache.

• Naratriptan 0.25 mg: 35 % of patients experienced relief from the headache.

• Naratriptan 0.1 mg: 32 % of patients experienced relief from the headache.

• Placebo: 34 % of patients reported headache relief.

2. Mild or No Clinical Disability (P < 0.05 Naratriptan 2.5 mg and 1 mg Versus Placebo, 1 mg Versus 0.1 mg, and 2.5 mg Versus 0.1 mg and 0.25 mg):

• Naratriptan 2.5 mg: 70 % patients.

• Naratriptan 1 mg: 63 % patients.

• Naratriptan 0.25 mg: 47 % patients.

• Naratriptan 0.1 mg: 48 % patients.

• Placebo: 48 % patients.

3. Four-Hour Efficacy for Absence of Migraine-Associated Symptoms: The efficacy was similar to the headache relief efficacy for each dose.

Complications or Side Effects:

• Cardiovascular and Cerebrovascular Complications - Inform patients of the possibility of cardiovascular side effects like myocardial infarction and cerebrovascular side effects like stroke. Patients should also be informed of what symptoms are indicative of cardiovascular issues to look for.

• Medication Overuse Headache - Warn patients of the ill effects of overusing the medication (more than ten days a month). Advise them to report to the hospital if they experience severe headaches after consistent use of Naratriptan.

• Serotonin Syndrome - Inform patients that Naratriptan may cause serotonin syndrome, particularly if used concomitantly with selective serotonin reuptake inhibitors (SSRIs), MAO inhibitors, etc.

• Hypersensitivity and Anaphylaxis - Caution patients (especially those with sensitivity to allergens) on the use of Naratriptan as it may result in severe anaphylactic reactions.

• Sedation and Dizziness - Patients should be informed that it may cause somnolence (drowsiness) or dizziness. Therefore, they shouldn't drive or use heavy machines.

Special Considerations:

• Renal Impairment: Naratriptan clearance is reduced in individuals with severe renal impairment. Mild to moderate renal impairment patients should start with 1 mg and may take a maximum of 2.5 mg daily.

• Hepatic Impairment: Naratriptan clearance is reduced in patients with severe hepatic impairment. Mild to moderate hepatic impairment patients may start with 1 mg and work up to 2.5 mg per day.

• Pregnancy: Naratriptan may cause fetal harm and should be used with caution in pregnant women.

Key Takeaway From iCliniq

Migraines can severely take a toll in one’s life if not treated on time. Naratriptan is a well-known drug used to treat migraines quickly. To get the best results, you can always ask iCliniq doctors, who can guide you well and also inform you about the possible side effects.