1. MALARIA
INTRODUCTION:
DEFINITION :-Malaria is a mosquito-borne infectious disease that affects humans and other
animals which is caused by single-celled microorganisms of the Plasmodium group.
AETIOLOGY :-
•Causative agent : Caused by a parasitic one celled organism, a protozoan called
Plasmodium: 4 types
-P.Vivax
-P.Malariae
-P.Ovale
-P.Falciparum
•Transmission : Malaria is transmitted through the bite of an infected female Anopheles
mosquito
•95% of infections are caused by the last two combined.
PATHOPHYSIOLOGY:-
The mosquito bite introduces the parasites from the mosquito's saliva into a person's blood.
The parasites travel to the liver where they mature and reproduce,where they multiply into
thousands of merozoites. The merozoites infect red blood cells and replicate, infecting more
and more red blood cells. Some parasites form gametocytes, which are taken up by a
mosquito, continuing the life cycle.
2. General Life cycle of Plasmodium:-
The malaria parasite called Plasmodium completes its life cycle in three
stages namely Gametocytes which is the first stage then sporozoites which is the
second stage and lastly merozoites which is the third and final stage.
SIGNS & SYMPTOMS:-
•Adults with malaria tend to experience chills and fever :
-classically in periodic intense bouts lasting around six hours
-followed by a period of sweating and fever relief &
-Headache
-fatigue
-abdominal discomfort , and
-muscle pain.
•Children tend to have more general symptoms:
-fever
-cough
-vomiting
-diarrhoea
3. •Initial manifestations :-
common to all malaria species are
-flu-like symptoms
- other conditions such as : sepsis gastroenteritis, and viral diseases.
•The presentation may include :
-headache
-fever
-shivering
-joint pain
-vomiting
-hemolytic anaemia
-jaundice
-haemoglobin in the urine
-retinal damage, and convulsions.
DIAGNOSIS:-
To diagnose malaria, your doctor will likely review your medical history and recent travel,
conduct a physical exam, and order blood tests. Blood tests can indicate:
•The presence of the parasite in the blood, to confirm that you have malaria
•Which type of malaria parasite is causing your symptoms
•If your infection is caused by a parasite resistant to certain drugs
•Whether the disease is causing any serious complications.
•Some other tests include:-
-Thin blood smear
-Rapid diagnostic test to detect circulating Ag of P.falciparum
-Haemoglobin ↓
-ESR ( Erythrocyte sedimentation rate)
4. -Liver function tests( ALT,AST)
-Fluorescent microscopy
-Polymerase chain reaction.
COMPLICATIONS:-
•Respiratory compensation of metabolic acidosis
• Noncardiogenic pulmonary oedema
•concomitant pneumonia
•severe anaemia.
•Acute respiratory distress
•Coinfection of HIV with malaria increases mortality.
•Kidney failure
•Cerebral malaria
•Encephalopathy
•An enlarged spleen, enlarged liver or both of these
•severe headache
• low blood sugar
•Haemoglobin in the urine with kidney failure may occur.
•Malaria in pregnant women is an important cause of stillbirths
- infant mortality
- miscarriage and
-low birth weight.
TREATMENT:-
Malaria is treated with prescription drugs to kill the parasite. The types of drugs
and the length of treatment will vary, depending on:
•The type of malaria parasite present in the body.
•The severity of patient's symptoms
•Age & sex
•Whether the patient is pregnant (in case female).
Medications:
The most common antimalarial drugs include:
1)Chloroquine phosphate :
Chloroquine is the preferred treatment for any parasite that is sensitive to the
drug. But in many parts of the world, parasites are resistant to chloroquine, and the drug is no
longer an effective treatment.
2)Artemisinin-based combination therapies (ACTs):
ACT is a combination of two or more drugs that work against the malaria
parasite in different ways. This is usually the preferred treatment for chloroquine-resistant
malaria.
Examples include :artemether-lumefantrine (Coartem) and artesunate-mefloquine.
3)Other common antimalarial drugs include:
•Atovaquone-proguanil (Malarone)
•Quinine sulphate (Qualaquin) with doxycycline (Oracea, Vibramycin, others)
•Primaquine phosphate
6. For uncomplicated P.falciparum malaria:
Artemisinin-based combination therapies (ACTs) are the recommended treatments for
uncomplicated falciparum malaria.
The following ACTs are recommended:
– Artemether + lumefantrine;
– Artesunate + amodiaquine
– Artesunate + mefloquine
– Artesunate + sulfadoxine-pyrimethamine, and
– Dihydroartemisinin + piperaquine .
Pharmacotherapy for Malaria in pregnancy:
Contraindications:-
→Primaquine is contraindicated in pregnancy during any trimester. Also contraindicated in
infants .
→Artemisinin-based combination therapies (ACTs) are contraindicated in the first trimester
of pregnancy.
Side effects :
•Severe hypoglycemia; especially use of quinine causes hypoglycemia(so, advice to take
with food.)
•Blue colour lips
•Dark coloured urine
•Hematuria.
7. Pharmacotherapy for Malaria with Mixed infection or complication/Drug Resistance:
There are currently three recommended treatments for severe and complicated malaria:
•Artesunate (AS) - 60mg - BID - IV - for 3 days.
•Artemether (AM) - 40mg - OD - IM - for 3 days.
•Quinine or quinidine {although in many countries only quinine is available.} - 300mg(PO)
- BID - for 7 days ; (Or) 16.4 mg IV .{16mg of quinine = 20mg of quinine dihydrochloride}
+
5% w/v of Glucose (500ml)
+
LINEZOLID +CEFIXIME →for 7days (BID) or IM - for 3 days.
REFERENCES:
Clinical Pharmacy & Therapeutics – Roger & Walker, Churchill
Livingstone Publication.
https://images.app.goo.gl/QtxkNk9Xe9WbNps56
https://en.m.wikipedia.org/wiki/Malaria
