Healthcare Communications

Artemether

 

Artemether In Malaria

* Resistance to commonly used antimalarials; need for newer and effective agents
* Qinhausou derivatives used in China for ages
* Efficacy even against parasite resistant to the antimalarials

 

 

Chemistry

* Sesquiterpene lactone, methyl esterified product of dihydroartemesinin
* More lipid soluble them artemesinin

 

Spectrum

- Plasmodium vivax and P. falciparium including resistant strains

 

Mechanism of Action

Active metabolite of all artemesinin derivatives is dihydroartemesinin. Acts by
- Inhibition of protein synthesis in trophozite growth phase
- Membrane lysis of parasite cell
- Activating host immunity - Decreased adherence of RBCs

 

Pharmacokinetics

* Administered IM
* Half life = 12 hours approx
* Plasma protein binding > 75%

Indications

* Should be reserved for malaria unresponsive to conventional drugs
* Severe Plasmodium falciparum malaria, with brain, liver, kidney, heart, or lung involvement

 

Dosage

5 day regimen :
Adults : 80 mg B. D. or day
1 80 mg O. D. on days 2-5
Children : 1.6 mg/kg BD on day1
1.6 mg/kg OD on days 2-5

3 day regimen :
Adults : 480 mg
Children : 9.6 mg/kg

 

 

Adverse Effects

* Cardiotoxicity - bradycardia, AV block
* G. I. - Nausea, vomiting, abdominal cramps
* Reduced reticulocytes & leucocytes, increased serum transmurases
* Safety in pregnancy / lactation not established

 

Drug Interactions

* Additive - QT Prolongation Effect with Terfenadine, astemizole, quinidine, disopyramide, procanamide, erythromycin, amiodarone, tricyclic antidepressants, some phenothiazines
* Antimalarial Synergism - Tetracycline, mefloquine, primaquine
* Antagonism - Pyrimethamine, sulphadoxine

 

Contraindications
* Hypersensitivity

Precautions
* Renal / Hepatic disease
* Prolonged QT interval

 

Place in Therapy

* Effective antimalarial, for malaria unresponsive to conventional drugs
* Used in severe Plasmodium falciparum malaria, and malaria with liver, brain, kidney, heart or lung involvement