what is malaria? how is malaria treatment & Best medication?

what is malaria? how is malaria treatment & medication?

Malaria is a parasitic infection spread by female Anopheles mosquitoes: The Plasmodium parasite that causes malaria is neither a virus nor a bacterium-it is a single-celled parasite(protozoa) that multiplies in red blood cells of humans as well as in the mosquito intestine.

Different species of Plasmodium:-

• P. vivax and P. ovale causes Benign Tertian Malaria
• P malariae causes quartan malaria
• P. Falciparum causes Malignant Tertian Malaria because it may cause kidney failure, Pulmonary oedema and cerebral malaria.

Definitive Host:- Human

Intermediate Host:- female Anopheles mosquito.

Infective Stage:-Sporozoite

Clinical features:-

The classic symptom of malaria is the cyclical occurrence of sudden chills followed by rigor and fever occurring every two days in P vivax and P ovale infections and every three days for P. malariae.

Sometimes fever may be continuous.

Fever occurs when infected RBC ruptures which cause the release of thousands of merozoites along with pyrogens TNF and polymerized haem. Periodic release of merozoites is associated with a paroxysm of fever with rigor.

• Recrudescence-Sometimes fever may subside temporarily but appears again. It is due to parasites surviving in the blood or as a result of inadequate or ineffective treatment. It is common in P. FALCIPARUM infection.

signs and symptoms of malaria are:-

• abdominal pain
• chills and sweating when the fever subsides.
• diarrhea (diarrhea is common in pediatric cases).
• headache
• high fever
• jaundice
• low blood pressure causing dizziness if a patient moves from lying or sitting position to standing position (also called orthostatic hypotension)
• muscle aches
• poor appetite
• hepatosplenomegaly

Complications of Malaria:-

1. Cerebral coma
2. Anemia
3. Pulmonary edema
4. Renal Failure
5. Shock
6. Lactic acidosis
7. Hypoglycemia
8. Splenomegaly
9. In Pregnancy (a) Maternal death (b) Stillbirth (c) Low birth weight (d) Anemia
10. Splenic rupture

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WHO-recommended oral rehydration salts

Whitfield ointment uses

pathophysiology of asthma

Diagnosis of Malaria:-

(a) clinical picture:- fever, chills-travel history – fever pattern

(b) examination of blood: – Malarial parasite is seen.

Clinical cure – the eradication of RBC trophozoites and schizonts

Radical cure – the eradication of RBC trophozoites and schizonts and hepatic schizonts. Primaquine is used for radical cure.

How is malaria treatment & medication?

Tab Chloroquine (base)600 mg stat followed by 300 mg after 8 hours (first day) then 300 mg once daily for next 2 days.

Tab Primaquine 15 mg once daily orally for 14 days,

Tab Paracetamol 500 mg orally 6 hourly for fever.

Drugs for malaria treatment:-

CHLOROQUINE:-

• Synthetic 4-aminoquinoline is available as chloroquine phosphate for oral use.
• Route of administration -oral/i.m./slow i.v.
• Extensively concentrated in the liver, cornea, and RBC causing large and. So the first dose is given as loading dose and then the maintenance dose is given which is half of the loading dose.
• Half life-3-4 days

Mechanism f Action:-

Malarial parasites digest hemoglobin to utilize amino acids. The released home is highly toxic. But the parasite converts this haem to hemozoin by haem polymerase. Chloroquine inhibits haem polymerase so free haem becomes toxic to the parasite.

• Chloroquine shows preferential accumulation in parasitized erythrocytes.
• Kills erythrocytic stage, gametocidal in P.vivax & ovale.
• Used in chemoprophylaxis also.
• Other uses are rheumatoid arthritis and amoebic abscess, DLE, lepra reaction, infectious mononucleosis.

Adverse effects:-

Nausea, vomiting, blurred vision; hypotension, and T wave abnormality on i.v. injection. It causes retinopathy which is irreversible on long-term use.

Dose:- Tab Chloroquine-600 mg base stat, followed after 6-8 hrs by 300 mg then 300 mg daily for 2 days with food.

PRIMAQUINE:-

• Synthetic 8-aminoquinoline.
• Widely distributed rapidly metabolized in Iver, excreted in the urine,t1/2 3-6 hrs, toxic metabolites cause hemolysis.
• Inhibits coenzyme q governed respiration in parasites.
• Pre-erythrocytic, exo-erythrocytic, and hypnozoites are killed and is gametocidal also.So it provides radical cure & prevents relapse of P.vivax & ovale.
• Also used in Pneumocystis jiroveci pneumonia.
• It causes Hemolytic anemia in G6PD deficiency, so before prescribing it G6PD test should be done. It is not used in pregnancy.
• Used in P. falciparum for gametocidal action. (single 45 mg tab)

DOSE:- 15 mg daily for 14 days in P.vivax infection.

In Chloroquine Resistance cases other drugs used are:-

Quinine:-

Adverse effects:- It is bitter in taste. So causes nausea and vomiting. It also causes hypotension and arrhythmia on bolus i.V. injection. It also causes hypoglycemia and cinchonism.

Cinchonism:- It occurs when quinine is administered for long-duration Symptoms resemble Salisylism.

Symptoms:- Ringing in ears nausea, headache, visual impairment, tinnitus, deafness, vertigo, blurred vision, disturbance in color vision, and photophobia. Treatment is symptomatic.

Dose:- 600 mg 8 hourly for 7 days or in serious cases 20 mg/kg (loading dose)diluted in 5% dextrose and infused i.v. over 4 hours Switch to oral 10 mg/kg 8 hourly to complete 7 days course.

SULFADOXINE-PYRIMETHAMINE ARTEMISININ-BASED COMBINATION THERAPY (ACT):-

WHO has recommended that all cases of acute uncomplicated falciparum malaria should be treated only by combining one of the artemisinin compounds with another effective erythrocytic schizonticides.

WHO APPROVED ACTS FOR UNCOMPLICATED P.falciparum MALARIA:-

• Artemether/Lumefantrine-Atm80mgBDx3days:Lume 480 mg BDx3days
• Artesunate/Mefloquine-AS100mgBDx3days;MQ750mgon 2 day+ 500mg on 3 day
• Arterolane(maleate)/Piperaquine-Art 150 mg dailyx3days:PPQ750mg dailyx3days

CHEMOPROPHYLAXIS:-

• Chloroquine 600mg(free base) on the first and last day orally; in between chloroquine 300mg weekly, and then primaquine 0.5mg/kg orally.
• For chloroquine resistant P.falciparum
  • Mefloquine200mg weekly orally; starting a week before and ending 4 weeks after leaving
  • Doxycycline 100mg orally daily from a day before travel and till a month after return from the endemic area.