Sumatriptan

Pronunciation: (SOO-ma-TRIP-tan)Class: Selective 5-HT ₁ receptor agonist

Trade Names:Imitrex- Injection 4 mg per 0.5 mL (as succinate)- Injection 6 mg per 0.5 mL (as succinate)- Spray, nasal 5 mg- Spray, nasal 20 mg- Tablets 25 mg (as succinate)- Tablets 50 mg (as succinate)- Tablets 100 mg (as succinate)

Apo-Sumatriptan (Canada)CO Sumatriptan (Canada)Gen-Sumatriptan (Canada)Imitrex DF (Canada)Novo-Sumatriptan (Canada)Novo-Sumatriptan DF (Canada)PMS-Sumatriptan (Canada)ratio-Sumatriptan (Canada)Sandoz Sumatriptan (Canada)

Pharmacology

Selective agonist for vascular serotonin (5-HT) receptor subtype, causing vasoconstriction of cranial arteries.

Pharmacokinetics

Absorption

Sumatriptan T _max for subcutaneous, oral, and intranasal administration is 0.17, 1.5, and 1.5 h, respectively. C _max for subcutaneous, oral, and intranasal administration is 72, 54, and 13 mg/L, respectively. AUC for subcutaneous, oral, and intranasal administration is 90, 158, and 48 mcg/L•h, respectively. Bioavailability for subcutaneous, oral, and intranasal administration is 96%, 14%, and 15.8%, respectively.

Distribution

Sumatriptan protein binding is 14% to 21%.

Elimination

Sumatriptan t _½ for subcutaneous, oral, and intranasal administration is 2, 2, and 1.8 h, respectively.

Special Populations

Hepatic Function Impairment

Bioavailability following oral administration may be markedly increased in patients with liver disease.

Race

No apparent difference in pharmacokinetics based on race.

Indications and Usage

Acute treatment of migraine attacks with or without aura; treatment of acute cluster headaches (injection only).

Contraindications

IV use (causes coronary vasospasm); patients with history, signs, or symptoms of ischemic heart disease (eg, angina, including Prinzmetal variant; MI; silent myocardial ischemia); cerebrovascular or peripheral vascular syndromes; uncontrolled hypertension; concurrent use or use within 24 h of ergotamine-containing preparations; management of hemiplegic or basilar migraine; severe hepatic function impairment; hypersensitivity to any component of the product.

Dosage and Administration

Adults

PO Recommended dose is up to 100 mg taken with fluids. Doses of 100 mg have not been proven to provide a greater effect than 50 mg. If headache returns, a single additional dose may be taken after 2 h up to a max of 200 mg per day. If headache returns following an initial dose with the injection, additional doses of single tablets (up to 100 mg per day) may be given with an interval of at least 2 h between tablet doses. Subcutaneous Administer as soon as symptoms appear. Max single adult dose is 6 mg. Max dose per 24 h is two 6 mg injections separated by at least 1 h. Available in auto-injection prefilled syringe devices that deliver 4 or 6 mg for easy use; however, lower doses should be used in patients who have adverse reactions at the usual dose.

Intranasal Administer a single dose of 5, 10, or 20 mg in one nostril. A 10 mg dose can be achieved by the administration of a single 5 mg dose in each nostril. If headache returns, the dose may be repeated once after 2 h. Do not exceed a total daily dose of 40 mg.

Hepatic Function Impairment

Max single dose is 50 mg.

Storage/Stability

Store tablets and nasal spray at ambient room temperature (47° to 86°F) or in refrigerator (36° to 46°F). Store injectable at 36° to 86°F. Protect from light. Protect nasal spray and injection from light.

Drug Interactions

5-HT ₁ agonists (eg, naratriptan)

Increased risk of vasospastic reactions; therefore, coadministration of two 5-HT ₁ agonists within 24 h of each other is contraindicated.

Ergot-containing drugs

May cause additive prolonged vasospastic reactions. Avoid use within 24 h of each other.

MAOIs

Sumatriptan concentrations may be elevated, increasing the risk of serious adverse reactions (eg, coronary artery vasospasm). Therefore, when possible, avoid coadministration.

Selective serotonin reuptake inhibitors (eg, citalopram, fluoxetine, fluvoxamine, paroxetine, sertraline)

Weakness, hyperreflexia, and incoordination have been reported rarely.

Sibutramine

Serotonin syndrome, including CNS irritability, motor weakness, shivering, myoclonus, and altered consciousness, may occur.

Laboratory Test Interactions

None well documented.

Adverse Reactions

Cardiovascular

Flushing (7%); decreased or increased BP, palpitation, syncope (at least 1%); atrial fibrillation, cardiomyopathy, colonic ischemia, Prinzmetal variant angina, pulmonary embolism, shock, thrombophlebitis (postmarketing).

CNS

Dizziness/vertigo (12%); paresthesia (5%); drowsiness/sedation, malaise or fatigue (3%); headache (2%); anxiety (1%); cerebrovascular accident, dysphasia, panic disorder, subarachnoid hemorrhage, vasculitis (postmarketing).

Dermatologic

Sweating (2%); exacerbation of sunburn (postmarketing).

EENT

Unusual taste (25% intranasal); discomfort in nasal cavity or sinuses (4%); throat discomfort (3%); visual alterations (1%); allergic rhinitis, ear, nose, and throat hemorrhage, external otitis, hearing loss, nasal inflammation, sensitivity to noise, sinusitis, tinnitus, upper respiratory inflammation (at least 1%); deafness, ischemic optic neuropathy, loss of vision, retinal artery occlusion, retinal vein thrombosis (postmarketing).

GI

Mouth or tongue discomfort (5%); nausea, vomiting (4% [14% intranasal]); jaw discomfort (2%); abdominal discomfort, dysphagia (1%); diarrhea, gastric symptoms (at least 1%); ischemic colitis with rectal bleeding, xerostomia (postmarketing).

Genitourinary

Acute renal failure (postmarketing).

Hematologic

Hemolytic anemia, pancytopenia, thrombocytopenia (postmarketing).

Hepatic

Elevated LFTs (postmarketing).

Hypersensitivity

Allergic vasculitis, anaphylaxis/anaphylactoid reactions, erythema, pruritus, rash, shortness of breath, urticaria (postmarketing).

Local

Injection-site reaction (59%); contusion, induration, lipoatrophy (subcutaneous), pain, redness, stinging, subcutaneous bleeding, swelling (postmarketing).

Musculoskeletal

Neck pain or stiffness, weakness (5%); myalgia (2%); muscle cramps (1%).

Respiratory

Bronchospasm (1%); dyspnea (at least 1%).

Miscellaneous

Tingling (14%); warm/hot sensation (11%); burning sensation (8%); feeling of heaviness or pressure (7%); feeling of tightness, numbness (5%); cold sensation, tightness in chest (3%); feeling strange, head tightness, pain, pressure in chest (2%).

Precautions

Monitor Exclude potentially serious neurologic conditions before treating headaches in patients not previously diagnosed with migraine or cluster headache.

Pregnancy

Category C .

Lactation

Excreted in breast milk.

Children

Safety and efficacy not established.

Elderly

Use is not recommended because elderly patients are more likely to have decreased hepatic function, they are at higher risk of coronary artery disease, and blood pressure increases may be more pronounced.

Hypersensitivity

Life-threatening and fatal hypersensitivity reactions (eg, anaphylaxis or anaphylactoid) have been reported.

Renal Function

Use caution.

Hepatic Function

Use caution.

Special Risk Patients

Use with caution in patients with diseases that may alter absorption, metabolism, or excretion of drugs (eg, hepatic or renal function impairment); use with caution in patients with a history of epilepsy or conditions associated with lowered seizure thresholds.

Cardiac events/vasoconstriction

Serious coronary events, some resulting in death, can occur after sumatriptan use. Administer first dose in health care provider's office to patients at possible risk of unrecognized coronary disease. If symptoms consistent with angina occur, conduct ECG evaluation for ischemic changes. May cause coronary vasospasm in patients with history of coronary heart disease. Rare reports of MI, major arrhythmias, angina symptoms, and death.

Cerebrovascular events

Cerebral hemorrhage, subarachnoid hemorrhage, stroke, and other cerebrovascular events have been reported.

Hypertensive crisis

Elevation in BP, including hypertensive crisis, have been reported.

Melanin binding

Because sumatriptan binds to melanin, it may accumulate in melanin-rich tissues (eg, eye), possibly causing toxicity after extended use.

Other vasospastic events

Peripheral vascular ischemia and colonic ischemia with abdominal pain and bloody diarrhea have been reported. Also, transient and permanent blindness and partial vision loss have been reported.

Serotonin syndrome

Life-threatening serotonin syndrome may occur, particularly when combined with serotonin reuptake inhibitors.

Overdosage

Symptoms

Ataxia, cyanosis, erythema of extremities, inactivity, injection-site reactions (eg, desquamation, hair loss, scab formation), mydriasis, paralysis, reduced respiratory rate, seizures, tremor.

Patient Information

• Advise patient to read patient information leaflet before starting therapy and again with each refill.
• Explain that drug is to be used only during migraine (or cluster headache if using injection) and does not prevent or reduce the number of attacks. Emphasize that drug is used only to treat actual migraine attack (or cluster headache if using injection) and should not be used to prevent headaches or treat headaches caused by other conditions.
• Advise patient that drug is to be taken as soon as symptoms of migraine appear. A second dose may be taken if symptoms return, but no sooner than 2 h (1 h for injection) following the first dose. For a given attack, if there is no response to the first tablet, advise patient to not take a second dose without first consulting with health care provider.
• Advise patient not to take more than 200 mg per day if using tablets, 40 mg per day if using nasal spray, or 12 mg per day if using injection.
• Advise patient that safety of treating more than 4 headaches in a 30-day period has not been established and to inform health care provider if headaches are occurring more frequently.
• Advise patient to immediately notify health care provider if any of the following occur after taking a dose of sumatriptan: severe chest pain or chest pain that does not go away; shortness of breath; sudden and/or severe stomach pain; swelling of eyelids, face, or lips; wheezing.
• Advise patient that if tightness, pain, pressure, or heaviness in chest, throat, neck, or jaw occurs when using sumatriptan, to discuss these symptoms with health care provider before using again.
• Advise patient to notify health care provider if feelings of tingling, heat, flushing, tiredness, dizziness, heaviness, or pressure occur after treatment.
• Advise patient that drug may cause fatigue or dizziness and to use caution while driving or performing other activities requiring mental alertness.
• Advise patient to avoid unnecessary exposure to sunlight or tanning lamps and to use sunscreen and wear protective clothing to avoid photosensitivity reactions.
• Instruct patient to continue taking prescribed migraine prophylactic medications daily as directed.
• Advise patient not currently taking a migraine prophylactic drug to discuss the use of such drugs with health care provider.

• Injection
• Ensure that patient or caregiver understands how to store, prepare, and administer the dose and dispose of used equipment and supplies.

Copyright © 2009 Wolters Kluwer Health.