RIZATRIPTAN BENZOATE
| RIZATRIPTAN BENZOATe (ri-za-trip'tan ben'zo-ate) Maxalt, Maxalt-MLT Classifications: serotonin 5-ht1 receptor agonist; Therapeutic:antimigraine Prototype: Sumatriptan Pregnancy Category: C |
Availability
5 mg, 10 mg tablets; 5 mg, 10 mg disintegrating tablets
Action
Selective (5-HT1B/1D) receptor agonist. The agonist effects at 5-HT1B/1D reverse the vasodilation of cranial blood vessels associated with a migraine.
Therapeutic Effect
Activation of the 5-HT1B/1D receptors reduces the pain pathways associated with the migraine headache as well as reversing vasodilation of cranial blood vessels.
Uses
Acute migraine headaches with or without aura.
Contraindications
Hypersensitivity to rizatriptan; CAD; Prinzmetal's angina (potential for vasospasm); ischemic heart disease; risk factors for CAD such as hypertension, hypercholesterolemia, obesity, diabetes, smoking, and strong family history; concurrent administration with ergotamine drugs or sumatriptan; concurrent administration with MAOIs; basilar or hemiplegic migraine; pregnancy (category C).
Cautious Use
Hypersensitivity to sumatriptan; renal or hepatic impairment; lactation; hypertension; asthmatic patients. Safety and effectiveness in patients <18 y are not established.
Route & Dosage
| Acute Migraine Adult: PO 5–10 mg, may repeat in 2 h if necessary (max: 30 mg/24 h); 5 mg with concurrent propranolol (max: 15 mg/24 h) |
Administration
Oral- Give any time after symptoms of migraine appear. If symptoms return, a second tablet may be given but no sooner than 2 h after the first.
- Do not exceed 30 mg (three doses) in any 24 h period.
- Do not give within 24 h of an ergot-containing drug or another 5-HT1 agonist.
- Store at 15°–30° C (59°–86° F) and protect from light and moisture.
Adverse Effects (≥1%)
Body as a Whole: Asthenia, fatigue, pain, pressure sensation, paresthesias, throat pressure, warm/cold sensations. CNS: Somnolence, dizziness, headache, hypesthesia, decreased mental acuity, euphoria, tremor. CV: Coronary artery vasospasm, transient myocardial ischemia, MI, ventricular tachycardia, ventricular fibrillation, chest pain/tightness/heaviness, palpitations. GI: Dry mouth, nausea, vomiting, diarrhea. Respiratory: Dyspnea. Skin: Flushing. Endocrine: Hot flashes.Interactions
Drug: Propranolol may increase concentrations of rizatriptan, use smaller rizatriptan doses; dihydroergotamine, methysergide, other 5-ht1 agonists may cause prolonged vasospastic reactions; ssris have rarely caused weakness, hyperreflexia, and incoordination; maois should not be used with 5-HT1 agonists. Herbal: St. John's wort may increase triptan toxicity.Pharmacokinetics
Absorption: 45% of oral dose reaches systemic circulation. Peak: 1–1.5 h for oral tabs; 1.6–2.5 h for orally disintegrating tablets. Metabolism: Via oxidative deamination by monoamine oxidase A. Elimination: Primarily in urine (82%). Half-Life: 2–3 h.Nursing Implications
Assessment & Drug Effects
- Monitor cardiovascular status carefully following first dose in patients at risk for CAD (e.g., postmenopausal women, men >40 y, persons with known CAD risk factors) or coronary artery vasospasms.
- ECG is recommended following first administration of rizatriptan to someone with known CAD risk factors.
- Report immediately to physician: chest pain or tightness in chest or throat that is severe or does not quickly resolve.
- Monitor periodically cardiovascular status with continued rizatriptan use.
Patient & Family Education
- Do not exceed 30 mg (three doses) in 24 h.
- Allow orally disintegrating tablets to dissolve on tongue; no liquid is needed.
- Contact physician immediately if any of the following develop following rizatriptan use: symptoms of angina (e.g., severe and/or persistent pain or tightness in chest or throat), hypersensitivity (e.g., wheezing, facial swelling, skin rash, or hives), abdominal pain.
- Report any other adverse effects (e.g., tingling, flushing, dizziness) at next physician visit.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug