rizatriptan benzoate

rizatriptan benzoate

Maxalt, Maxalt-MLT

Pharmacologic class: Serotonin 5-hydroxytryptamine (5-HT₁) receptor agonist

Therapeutic class: Antimigraine drug

Pregnancy risk category C

Action

Thought to act as agonist at specific 5-HT₁ receptor sites in intracranial vessels, causing vasoconstriction. Also may act on sensory trigeminal nerves, reducing transmission along pain pathways.

Availability

Tablets: 5 mg, 10 mg

Tablets (orally disintegrating): 5 mg, 10 mg

⊘Indications and dosages

➣ Acute migraine

Adults: 5 to 10 mg P.O.; may repeat in 2 hours, not to exceed 30 mg in 24 hours. For patients receiving propranolol concurrently, 5 mg P.O., up to a maximum of three doses in 24 hours.

Contraindications

• Hypersensitivity to drug or its components
• Ischemic heart disease or other significant cardiovascular disease
• Ischemic bowel disease
• Transient ischemic attacks
• Basilar or hemiplegic migraine
• Uncontrolled hypertension
• Use of other 5-HT₁ agonists or ergot-type compounds (dihydroergotamine, methysergide) within 24 hours
• MAO inhibitor use within past 14 days

Precautions

Use cautiously in:
• severe renal impairment (especially in dialysis patients), moderate hepatic impairment, cardiovascular risk factors
• phenylketonuria (PKU) in patients receiving orally disintegrating tablets
• pregnant or breastfeeding patients
• children younger than age 18 (safety not established).

Administration

• Place orally disintegrating tablet on patient's tongue to dissolve. Make sure he swallows it with saliva only. Don't give with beverages.
☞ Don't give within 14 days of MAO inhibitors (may cause serious adverse reactions).

Route	Onset	Peak	Duration
P.O.	30 min	1-1.5 hr	Unknown

Adverse reactions

CNS: headache, dizziness, drowsiness, asthenia, fatigue, paresthesia, decreased mental acuity, euphoria, tremor

CV: chest pain, tightness, heaviness, or pressure

GI: nausea, vomiting, diarrhea, dry mouth

Respiratory: dyspnea

Skin: flushing

Other: neck, throat, or jaw pain, tightness, or pressure; hot flashes; warm or cold sensations

Interactions

Drug-drug. Ergot or ergot-type compounds (such as dihydroergotamine, methysergide), other 5-HT₁ agonists: additive vasoactive effects

MAO inhibitors, propranolol: increased rizatriptan blood level, greater risk of adverse effects

Selective serotonin reuptake inhibitors: weakness, hyperreflexia, incoordination

Drug-herbs. S-adenosylmethionine (SAM-e), St. John's wort: increased risk of adverse serotonergic effects, including serotonin syndrome

Patient monitoring

• Monitor patient's response to drug. Assess need for repeat doses.
• Assess vital signs and cardiovascular status, especially if patient has cardiovascular risk factors.

Patient teaching

• Teach patient how to use drug. Stress that it's effective only in treating diagnosed migraine - not in preventing migraine or treating other types of headache.
• Advise patient to peel back blister pack of Maxalt-MLT with dry hands and place tablet on tongue. Tell him to swallow drug with saliva only, not beverages.
• Tell patient he may repeat dose in 2 hours if headache recurs, but should take no more than 30 mg in 24 hours.
• Inform patient with PKU that orally disintegrating tablets contain phenylalanine.
☞ Instruct female patient to immediately report possible pregnancy.
• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs and herbs mentioned above.