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artermether

artemether /lumefantrine anti-malarial

see also:

introduction

  • artemether is an anti-malarial usually combined with lumefantrine (marketed as Riamet)
    • this combination is the 1st line Rx in 2015 for uncomplicated falciparum malaria and for vivax acquired in Indonesia
    • the site of antiparasitic action of both components is the food vacuole of the malarial parasite, where they are thought to interfere with the conversion of haem, a toxic intermediate produced during haemoglobin breakdown, to the nontoxic haemozoin, malaria pigment

indications

  • Riamet tablet is indicated for the treatment of acute, uncomplicated malaria due to Plasmodium falciparum in adults, children and infants of 5 kg and above.
  • Riamet Dispersible tablet is indicated for the treatment of acute, uncomplicated malaria due to Plasmodium falciparum in children and infants weighing between 5 kg and less than 35 kg.
  • it is also active against blood stages of P. vivax, but not active against hypnozoites
  • NOT indicated for prophylaxis

contraindications

  • hypersensitivity
  • severe malaria where at least one of:
    • prostration; impaired consciousness or unarousable coma; failure to feed; deep breathing, respiratory distress (acidotic breathing); multiple convulsions; circulatory collapse or shock; pulmonary oedema (radiological); abnormal bleeding; clinical jaundice; haemoglobinuria
    • severe normocytic anaemia; haemoglobinuria; hypoglycaemia; metabolic acidosis; renal impairment; hyperlactatemia; hyperparasitemia
  • 1st trimester pregnancy
    • artemisinins are known to be embryotoxic and teratogenic in animals, causing cardiovascular and skeletal deformities thus it is C/I in 1st trimester
    • during the second and the third trimester, treatment should only be considered if the expected benefit to the mother outweighs the risk to the foetus
  • patients taking any drug which is metabolised by the cytochrome enzyme CYP2D6 (e.g. flecainide, metoprolol, imipramine, amitriptyline, clomipramine)
  • patients taking any drug metabolised by strong inducers of CYP3A4 (e.g. rifampicin, carbamazepine, phenytoin, St John's wort (Hypericum perforatum))

precautions

  • severe renal/liver/cardiac disease patients
  • antiretroviral drugs
  • safety and efficacy of Riamet or Riamet Dispersible tablets in children aged less than 3 months have not been adequately assessed
  • lactation
    • it is recommended that breastfeeding should not resume until at least four weeks after the last dose (as long elimination half-life of lumefantrine of 4-6 days), unless the potential benefits to the mother and child outweigh the risks of treatment

adverse effects

  • common: anorexia, nausea, vomiting, diarrhoea, abdominal pains, headache, dizziness, clonus, cough, rash, arthralgia, myalgia, fatigue, anaemia, splenomegaly, abnormal LFTs, decreased WCC, decreased platelet count
  • uncommon: urticaria, sleep disorders, palpitations, paraesthesiae
  • rare: prolonged QTc, hypersensitivity, haemolytic anaemia, hepatitis

dose

  • Riamet tablets for adults, adolescents, and children weighing greater than or equal to 35 kg or > 12 years of age:
    • six doses of four tablets (i.e. total course of 24 tablets), given over a period of 60 hours
    • 1st dose, given at the time of initial diagnosis, should be followed by five further doses given at 8, 24, 36, 48 and 60 hours thereafter
    • there is no information suggesting that the dosage in patients over 65 years of age should be different to younger adults
  • Riamet Dispersible tablets for infants and children weighing 5 kg to < 35 kg, and aged greater than or equal to 3 months up to 12 years:
    • Six doses of 1 to 3 dispersible tablets per dose, depending on bodyweight (i.e. total course of either 6, 12, or 18 tablets), given over a period of 60 hours.
      • 5 to < 15 kg bodyweight, and greater than or equal to 3 months.
        • One dispersible tablet at the time of initial diagnosis, 1 tablet again after 8 hours and then 1 tablet twice daily (morning and evening) on each of the following two days (total course comprises 6 tablets).
      • 15 to < 25 kg bodyweight.
        • Two dispersible tablets as a single dose at the time of initial diagnosis, 2 tablets again after 8 hours and then 2 tablets twice daily (morning and evening) on each of the following two days (total course comprises 12 tablets).
      • 25 to < 35 kg bodyweight, and < 12 years
        • Three dispersible tablets as a single dose at the time of initial diagnosis, 3 tablets again after 8 hours and then 3 tablets twice daily (morning and evening) on each of the following two days (total course comprises 18 tablets).
artermether.txt · Last modified: 2015/11/10 12:32 (external edit)