Malaria Chemoprophylaxis and treatment By Mohammed Mahmoud, MD

Distribution of malaria

Chemoprophylaxis Chloroquine resistant P.falciparum: Chloroquine resistant P.falciparum: - Mefloquine 250mg/week during exposure and for 4 weeks after leaving the endemic area - Doxycycline 100mg/day during exposure and for 4 weeks after leaving the endemic area - Malarone: 1 tab daily during exposure and for 1week after leaving the endemic area

Choloquine susceptible P.falciparum: Choloquine susceptible P.falciparum: choloquine 300 mg base /week during exposure and for 4 weeks after leaving the endemic area.

Treatment

Aim To terminate parasitemia as rapidly as possible to avoid the complications To terminate parasitemia as rapidly as possible to avoid the complications

Choice of drugs Local cost and availability Local cost and availability Drug resistance pattern in the country of origin of the parasite Drug resistance pattern in the country of origin of the parasite Age, pregnancy Age, pregnancy Known allergies Known allergies Prior chemoprophylaxis Prior chemoprophylaxis Risk of re exposure to malaria after treatment Risk of re exposure to malaria after treatment

Regimens of therapy Chloroquine susceptible malaria: Chloroquine susceptible malaria: - Chloroquine: Oral 600 mg base followed by 300 mg base after 6 h and then 300 mg base in 2 nd and 3 rd day. I.V infusion 5mg/kg over 3 h and repeated every 8 h to total dose of 25 mg/kg. I.M 2.5 mg/kg every 4 h to total dose of 25mg/kg.

Chloroquine resistant P.vivax: Chloroquine resistant P.vivax: - quinine sulphate 10 mg/kg 8 hourly for 7 days + Doxycycline 100 mg bid for 7 days - Oral Mefloquine 750 mg followed by 500 mg in 8-12 hours - Oral Halofantrine 500 mg/6h for 3 doses

Chloroquine resistant P.falciparum: Chloroquine resistant P.falciparum: a- uncomplicated malaria: - Oral quinine sulphate + Doxycycline or tetracycline 4 mg/kg for 7 days or fansidar (sulfdoxine 25mg/kg + pyremethamine 1.25 mg/kg single dose). - Oral Malarone (Atovaquone 250 mg + Proguanil 100 mg) 4 tablets daily for 3 days. very effective, very expensive, few resistance. - Oral Mefloquine - Oral Halofantrine 500 mg/kg for 3 doses to be repeated after one week.

- IV infusion of quinine dihydrochloride 10mg/kg every 8h until the patient can take oral medications.

b- complicated malaria (severe malaria): Coma, jaundice, renal failure, severe anemia, hyperpyrexia, high parasite load. Ttt in the ICU under ECG and glucose monitoring. - IV infusion of quinine dihydrochloride Loading dose of 20 mg/kg IV infusion over 4 hours followed by 10 mg/kg IV infusion every 8 hours until the patient can take oral medications. - Exchange transfusion if parasite index is > 30% or > 10% if the patient did not respond to drugs or > 10% if the patient did not respond to drugs

Multiply resistant P.falciparum: Multiply resistant P.falciparum: - Artesunate PR or Oral 4 mg/kg for 3 days + oral Mefloquine. To prevent relapse in P.ovale or vivax: To prevent relapse in P.ovale or vivax: - 15 mg primaquine base daily for 14 days mg primaquine base daily for 14 days.

Ttt of pregnant woman: Ttt of pregnant woman: - Drugs allowed in all trimester  Chloroquine, quinine, arthemether - 2 nd and 3 rd trimester  Mefloquine, pyrimethamine, Sulfdoxine - Contraindicated drugs  Primaquine, tetracycline, Doxycycline, Halofantrine, Malarone. N.B. in case of P. Vivax  chemoprophylaxis with cholorquine weekly until patient stops lactation, then full therapeutic dose of chloroquine and primaquine is given

Side effects Chloroquine  Hypotension, Corneal crystal deposition (acute effects), retinopathy (chronic effects) Chloroquine  Hypotension, Corneal crystal deposition (acute effects), retinopathy (chronic effects) Quinine  Cinconism (tinnitus, deafness, dizziness, nausea and vomiting), hypotension (fast infusion or overdose), hypoglycemia, abortion. Quinine  Cinconism (tinnitus, deafness, dizziness, nausea and vomiting), hypotension (fast infusion or overdose), hypoglycemia, abortion. Mefloquine  CNS (fits and psychosis), CVS (myocardial depressant). Mefloquine  CNS (fits and psychosis), CVS (myocardial depressant). Halofantrine  prolong QT interval  arrhythmia Halofantrine  prolong QT interval  arrhythmia Malarone  not used in severe renal insufficiency Malarone  not used in severe renal insufficiency Arthemeter  very safe Arthemeter  very safe

Thank You