7. Antimalarials .pptx

asdfghjkl

1. Antimalarials

2. Types of Malarial plasmodium – P. falciparum P. vivax P. ovale P. malariae P. knowlesi 1. Definition of Antimalarials – Antimalarials are the drugs used for prophylaxis, treatment and prevention of relapses of malaria.

3. Classification of Antimalarials – 4-aminoquinolones – Chloroquine, Amodiaquine, Piperaquine Cinchona alkaloids – Quinine, Quinidine Biguanides – Proguanil, Chlorproguanil 8-aminoquinolones – Primaquine Sesquiterpene lactones – Artesunate, Artemether, Alpha Beta Arteether. i) Chloroquine – - rapidly acting erythrocytic schizontocide Resistance – P. falciparum has developed significant resistance. ADR – Retinal damage, severe headache, abdominal pain, convulsions in children. Dosage – 600 mg of base stat 300 mg after 6 hours 300 mg OD for 2 days

4. ii) Quinine – - It is a levorotatory alkaloid from Cinchona bark. - It’s dextrorotatory form is useful in Arrhythmia. Resistance – Not resistant to P. falciparum ADR – More toxic & less effective hence used only during resistant cases. Cinchonism – repeated large doses of quinine causes cinchonism with clinical features like Tinnitus, vomiting, mental confusion, visual disturbances, diarrhoea. Quinine can also causes haemolysis especially during pregnancy. Dose – 10mg/kg or 600mg of Quinine hydrochloride is diluted in 500ml of 5% Dextrose and is infused over 2-3 hours, repeated over 8 hours till the patient regains consciousness.

5. iii) Primaquine – - Highly active against gametocytes and hypnozoites , Uses – radical cure of malaria and prevents relapses. Dose – 15mg OD for 2 weeks iv) Artesunate – - potent schizontocide - derived from the chinese herb A rtemisia annua Uses – effective against P. falciparum & P. vivax Dose – 60mg i.v. 12 hourly for first 3 doses and then 60mg OD for next 4 days

6. v) Artemether - - potent schizontocide - derived from the chinese herb Artemisia annua Uses – effective against resistant P. falciparum cases Dose – 80mg i.v. 12 hourly for first 3 doses and then 80mg OD for next 4 days vi) Alpha Beta Arteerther – - developed in India Uses – in cerebral malaria Dose – 150mg i.m. OD for 3 days. vii) Proguanil – - slow acting schizontocide Uses – prophylaxis of malaria in combination with chloroquine. Dose – 200mg OD daily and chloroquine 300mg weekly till 6 weeks after exposure.