Rizatriptan

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Rizatriptan belongs to a class of medicines called selective serotonin 5-HT 1B/1D receptor agonists or triptans.

Rizatriptan is indicated for the treatment of migraine headaches

Treatment with Rizatriptan reduces swelling of blood vessels surrounding the brain. This swelling results in the headache pain of a migraine attack.

Contents

[edit] BRAND NAMES

[edit] STRUCTURE

Rizatriptan.jpg

[edit] MECHANISM OF ACTION

Theories on the etiology of migraine headache suggest that symptoms are due to local cranial vasodilatation and/or to the release of vasoactive and pro-inflammatory peptides from sensory nerve endings in an activated trigeminal system.

Rizatriptan is a triptan drug. Triptans are 5-HT receptor agonists, they bind with high affinity to 5HT1B and 5HT1D receptors.

The agonist effects of Rizatriptan on these receptors results in extracerebral intracranial blood vessels constriction and in the inhibition of pro-inflammatory neuropeptide release from nerve endings.

Peak plasma levels occurs approximately 1-1,5 hours after dosing to healthy subjects and elimination half-life is approximately 2-3 hours.

[edit] INDICATIONS

Rizatriptan is indicated for the acute treatment of migraine with or without aura in adults and in pediatric patients 6 to 17 years of age(US). Rizatriptan is not intended for the prophylactic therapy of migraine or for use in the management of cluster headache.

[edit] DOSAGE

Rizatriptan comes in 5 and 10 mg tablets and in 5 and 10 mg disintegrating tablets

  • Adults: The recommended dose is 5-10 mg taken orally as early as possible after the onset of migraine. The choice of dose should be made on an individual basis, weighing the possible benefit of the 10 mg dose with the potential for a greater risk of adverse events. If the headache recurs after initial relief, a second tablet may be taken, providing there is an interval of at least 2 hours between doses. The total daily dose of Rizatriptan should not exceed 30 mg per day.
  • Pediatric patients 6 to 17 years: 5 mg single dose in patients less than 40 kg (88 lb); 10 mg single dose in patients 40 kg (88 lb) or more.
  • If co-administered with propranolol:
    • Adults: The recommended dose is 5 mg up tp a maximum of 3 doses (15 mg) in 24 hours period.
    • Pediatric patients: For pediatric patients weighing 40 kg (88 lb) or more, taking propranolol, only a single 5-mg dose of rizatriptan is recommended. In pediatric patients who weigh less than 40 kg (88 lb) taking propranolol, Rizatriptan should not be prescribed.

[edit] CONTRAINDICATIONS

  • Ischemic heart disease, coronary artery vasospasm, or other significant underlying cardiovascular disease (Triptans can produce a small contraction of human coronary arteries)
  • History of stroke or transient ischemic attack (TIA)
  • Cerebrovascular syndromes (e.g. history of stroke or transient ischaemic attack)
  • Peripheral Vascular Disease (including ischemic bowel disease)
  • Uncontrolled hypertension (Rizatriptan may increase blood pressure)
  • Concurrent administration or recent discontinuation (i.e., within 2 weeks) of a MAO-A inhibitor (see interactions)
  • Concomitant administration within 24 hours of an ergotamine derivative (e.g. Dihydroergotamine, ergotamine) or another Triptan.
  • Hemiplegic or basilar migraine
  • Hypersensitivity to Rizatriptan

[edit] WARNINGS AND PRECAUTIONS

  • Perform cardiac evaluation in patients with multiple cardiovascular risk factors (e.g., hypertension, hypercholesterolemia, smoker, obesity, diabetes, strong family history of coronary artery disease (CAD), female with surgical or physiological menopause, male over 40 years of age).
  • In case of chest discomfort, including pain, pressure, heaviness and tightness following Rizatriptan administration, patients should be evaluated for the presence of Coronary artery disease (CAD) or a predisposition to Prinzmetal variant angina before receiving additional doses.
  • Arrhythmias: Discontinue Rizatriptan if occurs
  • Cerebral hemorrhage, subarachnoid hemorrhage, and stroke: Discontinue Rizatriptan if occurs
  • Medication overuse headache: Overuse of acute migraine drugs for 10 or more days per month may lead to exacerbation of headache. Medication overuse headache may present as migraine-like daily headaches or as a marked increase in frequency of migraine attacks. Detoxification of patients, including withdrawal of the overused drugs, and treatment of withdrawal symptoms (which often include a transient worsening of headache) may be necessary.

[edit] INTERACTIONS

[edit] PREGNANCY AND LACTATION

  • Pregnancy Category C (US), Rizatriptan should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
  • Rizatriptan is extensively excreted in rat milk. Therefore, caution should be exercised when considering the administration to a nursing woman.

[edit] SIDE EFFECTS

The most common side effects in adults were: Dizziness, fatigue, somnolence and pressure sensation in the chest or throat

In very rare cases, coronary vasospasm and myocardial infarction have been reported. Periodic cardiovascular evaluation should be considered in intermittent long-term users of Rizatriptan who have cardiovascular risk factors. (e.g., increased age, diabetes, hypertension, smoking, obesity, strong family history of coronary artery disease)

[edit] RELATED LINKS

[edit] BIBLIOGRAPHY

http://www.merck.com/product/usa/pi_circulars/m/maxalt/maxalt_pi.pdf

[edit] REFERENCES

Antimigraine preparations
5 HT1 agonists (Triptans) Almotriptan (Almogran, Axert)   Eletriptan (Relpax)   Frovatriptan (Frova, Migard, Menatriptan)   Rizatriptan (Maxalt)   Sumatriptan (Imigran)   Zolmitriptan (Zomig)
Ergot alkaloids Dihydroergotamine   Ergotamine
NSAIDs/ Analgesics Indometacin   Acetylsalicylic acid (Aspirin)   Diclofenac (Voltaren)   Ibuprofen (Advil, Brufen, Dolgit, Nurofen)   Ketorolac (Toradol)   Naproxen (Naprosyn, Aleve)   Nimesulide   Paracetamol (Efferalgan, Panadol...)
Prophylaxis Cinnarizine (Stugeron, Stugeron forte)   Flunarizine (Sibelium)   Nifedipine (Adalat)   Pizotifen   Propranolol (Inderal)   Topiramate (Topamax)