بتـــــاريخ : 11/15/2008 8:15:40 AM
الفــــــــئة
  • الصحــــــــــــة
  • التعليقات المشاهدات التقييمات
    0 981 0


    Antiemetics

    الناقل : elmasry | العمر :42 | الكاتب الأصلى : H5N1 | المصدر : sayadla.com

    كلمات مفتاحية  :
    دواء Antiemetics

     
    Antiemetics

     
    They are the drugs that is effective against vomiting and nausea

    They are typically used to treat

    Motion sickness

     
    The side effects of opioid analgesics and chemotherapy
    directed against cancer

     
    And postoperative emesis


     
    Main classes of antiemetics


    Dopamine D2 antagonists


    Metoclopramide

    Domperidone

     
     
    Metopimazine





     
    5 HT3 receptor antagonists

    Granisetron

    Ondansetron

    Dolasetron

    Tropisetron




    Antihistamines

    Diphenhydramine

    Dimenhydrinate

    Meclizine

    Cyclizine



     
    (1)

     
    Dopamine D2 receptor antagonists


     
    (1)
    Metoclopramide






     
    Mode of action
    is a potent dopamine D2 receptor antagonist used for its antiemetic and prokinetic properties

     
    Thus it is primarily used to treat nausea and vomiting, and to facilitate gastric emptying in patients with gastric stasis

     
    The anti-emetic action of metoclopramide is due to its antagonist activity at D2 receptors in the CTZ

     
    At higher doses, 5-HT3 antagonist activity may also contribute to the anti-emetic effect


     
    The prokinetic activity of metoclopramide is mediated by mascarinic activity, D2 receptor antagonist activity
    The prokinetic itself may also contribute to the anti-emetic effect



     
    Clinical uses

     
    (1)
    Antiemetic use

    used to treat emesis associated with conditions including: emetogenic drugs, radiation sickness, malignancy, labour, and
     
     


     
    considered ineffective in post-operative nausea and vomiting
    and ineffective for motion sickness



     
    also used by itself or in combination with paracetamol for the relief of migraine

     
    as in








     
    (2)
    Prokinetic use

    Metoclopramide
    increases
    peristalsis
    increases tone and amplitude of gastric contractions
    relaxes the
     
     

    so
    it is useful in the treamtent of
    gastric stasis e.g. after gastric surgery
    also used in
     
     



    (3)
     
    Other indications

     
    By inhibiting the action of prolactin inhibiting hormone (i.e. dopamine), metoclopramide has sometimes been used to stimulate lactation


    Contraindications
    It should be used with caution in
     
     
    Parkinson's disease since, as a dopamine antagonist, it may worsen symptoms

    Obstruction, perforation, or hemorrhage of the stomach or small bowel

     
    Not given in the first trimester of pregnancy

    Metoclopramide hydrochloride is not recommended for patients under 18 years of age

    Adverse effects
    restlessness, drowsiness, dizziness, and headache
    Extrapyramidal side effects as parkinsonism like symptoms

    Dose
    The usual dose is 10 milligrams 30 minutes before each meal and at bedtime


    Trade names


     



     



     



     
    (2)
    Domperidone



     
    Mode of action
    Related to that of metoclopramide


     
    Uses

     
    (1)
    Antiemetic use
    used in the treatment of nausea and vomiting

    It is useful in patients with
    Parkinson's disease because, unlike metoclopramide , domperidone does not cross the BBB

     
    (2)
    Lactation
    Domperidone, by acting as an anti-dopaminergic, results in increased prolactin secretion, and thus promotes lactation


     
    Adverse effects
    no extrapyramidal side effects as it does not cross BBB


     
    Dose
    The usual dose is 10 milligrams 30 minutes before each meal and at bedtime


     
    Trade names

    (2)
     
    5 HT3 receptor antagonists



     
    (1)
    Granisetron

     

     
    Mode of action
    Granisetron is a serotonin5-HT3 receptor antagonist used to treat nausea and vomiting following chemotherapy

     
    It does not have much effect on vomiting due to motion sickness


     
    Clinical uses
    chemotherapy induced nausea and vomiting

     
    Post-operative and post-radiation nausea and vomiting


     
    Adverse effects
    Headache, dizziness, and constipations are the most commonly reported side effects associated with its use


     
    Dose
    Given intravenously about 30 minutes before beginning therapy


     
    Trade names



     
    (2)
    Ondansetron

     



     
    Mode of action

     
    Clinical uses

     
    Adverse effects

     
    As Granisetron


     
    Dose
    The drug is administered 1–3 times daily, depending on the severity of nausea and/or vomiting
    The normal dose for adults and children over the age of 12, is 8 mg initially, followed by a second dose of 8 mg, eight hours later. The drug is then administered once every 12 hours, usually not for more than 2-3 days


     
    Trade names

     



     
    (3)
    Dolasetron

     


     
    Mode of action

     
    Clinical uses

     
    Adverse effects

     
    Dose

     
    As Granisetron



     
    (4)
    Tropisetron


     
    Mode of action


     
    Clinical uses

     
    Adverse effects

     
    Dose

     
    As Granisetron


     
     
    Trade names

    كلمات مفتاحية  :
    دواء Antiemetics

    تعليقات الزوار ()