Rizatriptan

Indications

Rizatriptan is used for: Acute migraine attacks

Adult Dose

Oral Acute migraine attacks Adult: Initially, 10 mg. If ineffective, 2nd dose should not be taken for the same attack. If symptoms recur after initial response, a further dose of 10 mg may be given. Doses should be separated by at least 2 hr. Max: 20 mg/24 hr. If patient is also taking propanolol, initiate with 5 mg. Max: 10 mg/24 hr. Ensure that the 2 drugs are separated by at least 2 hr. Hepatic Impairment For mild-moderate impairment, initate with 5 mg. Further dose of 5 mg may be taken after an interval of at least 2 hr. Max: 10 mg/24 hr. Avoid in severe impairment.

Child Dose

Migraine Headache Acute treatment of migraine with or without aura <6 years: Safety and efficacy not established 6-17 years (<40 kg): 5 mg PO once q24hr 6-17 years: (40 kg or greater): 10 mg PO once q24hr Dosing considerations Efficacy and safety of treatment with more than 1 dose within 24 hours in pediatric patients has not been established 6-17 years (<40 kg) taking propranolol: Do not administer rizatriptan 6-17 years (>40 kg) taking propranolol: Limit dose to 5 mg PO once q24hr as necessary; not to exceed 5 mg/24hr

Renal Dose

Renal Impairment For mild-moderate impairment, initate with 5 mg. Further dose of 5 mg may be taken after an interval of at least 2 hr. Max: 10 mg/24 hr. Avoid in severe impairment.

Administration

May be taken with or without food.

Contra Indications

History of MI, peripheral vascular disease, transient ishaemic attack, ischaemic heart disease or Prinzmetal's angina; uncontrolled hypertension; basilar or hemiplegic migraine; severe hepatic or renal impairment. Adolescent <18 yr.

Precautions

Elderly; mild to moderate hepatic or renal impairment; coronary artery disease; pregnancy, lactation. May cause drowsiness. History of seizures. Ensure an interval of at least 24 hr after stopping an ergotamine compound and starting a serotonin (5-HT1) agonist. Lactation: Unknown; use with caution in breastfeeding

Pregnancy-Lactation

Interactions

Increased serum concentrations with propranolol. Increased risk of vasospastic reactions when used with ergotamine and methysergide. Concurrent use with SSRIs may increase risk of serotonin syndrome. Potentially Fatal: Concurrent use with or within 2 wk of stopping MAOI treatment.

Adverse Effects

Side effects of Rizatriptan : >10% Drowsiness (13-30%, dose related),Fatigue (13-30%, dose related),Dizziness (11-15%) 1-10% Dizziness (4-9%),Somnolence (4-8%),Fatigue (4-7%; dose related),Nausea (4-6%),Asthenia (1-5%),Hot flashes (1-5%),Paresthesia (3-4%),Dry mouth (3%),Chest pain (2-3%),Pain/pressure in chest, neck, throat, jaw (<2%),Headache (<2%),Dyspnea (>1%),Hypoesthesia (>1%),Palpations (>1%),Skin flushing (>1%) <1% Tachycardia,Angioedema,Wheezing,Hypertensive crisis,Bradycardia,Hallucination,Epidermal necrolysis,Hearing impairment,Arrhythmias,Myocardial infarction and coronary artery vasospasm in patients with CAD risk factors Potentially Fatal: Toxic epidermal necrolysis.

Mechanism of Action

Rizatriptan is a selective serotonin (5-HT1) agonist in cranial arteries responsible for vasoconstriction and reduction of inflammation associated with antidromic neuronal transmission.