1 / 17

Anti-malarial Drugs

Anti-malarial Drugs. Dr Chetna Desai Professor and Head Department of Pharmacology G.M.E.R.S. Medical College, Ahmedabad. Antimalarial drugs. Malaria is caused by four species of protozoa: Plasmodium malariae. P. falciparum. P. vivax. P. ovale (rare)

quinn-nielsen
Download Presentation

Anti-malarial Drugs

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Anti-malarial Drugs Dr Chetna Desai Professor and Head Department of Pharmacology G.M.E.R.S. Medical College, Ahmedabad

  2. Antimalarial drugs • Malaria is caused by four species of protozoa: • Plasmodium malariae. • P. falciparum. • P. vivax. • P. ovale (rare) • The plasmodium transmitted to human by the bite of an infected female anopheles mosquito.

  3. Malaria transmission life cycle: • Sporozoites  tissue schizonts (in liver)  merozoites infect RBC (blood schizonts) rupture of RBC (clinical attack)  new crops of merozoites • Sexual form: some merozoites differentiate into male & female gametocytes  ingested by a mosquito where they form Sporozoites human

  4. P. malariae & p. falciparum have one cycle of liver invasion and end by the 4th week i.e. no relapse occurs. • P.ovale & p. vivax have dormant stages (hypnozoites) in the liver. These hypnozoites may rupture months or years later causing relapse of the attacks.

  5. Choice of antimalarial drug • Efficacy and half-life • • Acceptability and adherence to treatment formulations) • • Effectiveness • • Adverse effects • • Drug interactions and contraindications • • Use in special groups, e.g. pregnant women, infants • • Capacity of health system to implement policy • • Cost-effectiveness, affordability of various regimens • • Reported resistance and/or cross-resistance

  6. Blood Schizonticides Chloroquine (4- aminoquinoline derivative) Mechanism of action: • Inhibits synthesis of DNA and RNA in the plasmodium. • Increases pH of the vacuoles in the parasite, so prevent its utilization of erythrocyte hemoglobin. Uses: • Acute attack

  7. Other uses: • Amebic liver abscess (as chloroquine is concentrated in the liver). • Anti-inflammatory in autoimmune diseases e.g. rheumatoid arthritis A/E: GIAE rash, headache, peripheral neuritis, cardiac depressant, retinal damage(X use > 5 years without regular ophthalmic examination), toxic psychosis.

  8. Quinine: Mechanism of action: • Inhibits DNA strand separation, transcription and protein synthesis. Uses: • CQ resistant P. falciparum (orally). • Cerebral malaria (i.v infusion until patient can take the drug orally). A/E: • Cinchonism i.e. headache, dizziness, & tinnitus. • Inhibits cardiac conductivity • hemolysis in G-6-P D and black water fever (intravascular hemolysis).

  9. Qinghaosu (Artemisinin) • Chinese herbal medicine used as antipyretic. • Blood schizonticide against all types of malaria including CQR PF • Unknown mechanism of action. Uses: • P. falciparum cerebral malaria (oral & parenteral). • Not used for prophylaxis • Used in pregnancy – only in 2nd & 3rd trimesters

  10. Antifolates (sulfonamides & sulfones): Synergistic blockade of folic acid synthesis • Sulfonamide inhibits dihydropteroate synthetase, inhibits folic acid synthesis. • Pyrimethamine and proguanil inhibit dihydrofolate reductase, so inhibit tetrahydrofolate (folinic acid synthesis).

  11. Fansidar • Combination of sulfadoxine and pyrimethamine. • It is used in CQ R PF. A.E: • Sulfonamide: rashes, renal damage, hemolysis & GIAE, SJ syndrome. • Pyrimethamine: FA deficiency, agranulocytosis Disadvantages: slow blood schizonticide activity, drug resistance & numerous serious adverse effects. C/I:pregnant & nursing women, G-6-PD, renal impairment & children under 2 months of age.

  12. Primaquine • Tissue schizonticide. • It has a cellular oxidant activity and possibly interferes with mitochondrial function. • Gametocide, so inhibits transmission of infection by mosquito. Uses: • Eradication of liver stages (hypnozoites) of P.vivax & P.ovale, after standard chloroquine therapy to prevent relapse. A/E:GIT upset, pruritus, headache, methemoglobinemia, hemolysis especially in G-6-PD.

  13. Doxycycline • Tetracycline derivative • Longer half life • Reliable absorption • Better safety profile in renal insufficiency • Use: • Drug resistant P Falciparum along with quinine • Prophylaxis

  14. Adverse Effects: • GIAE • Oesophageal ulceration • Take sufficient water • X Pregnancy and lactation, Children upto 8 years

  15. Clindamycin • Lincosamide antibiotic • Inhibits protein synthesis • 90% is absorbed by GIT • Use: CQ RPF • Safe in pregnancy and children • Lesser risk of resistance • A/E: ANVD • Pseudomembranous colitis • Hypersensitivity reactions • BM depression • Hepatic damage

  16. Thanks

More Related