What to Know About Chloroquine?

HEALTH:

These is the drug used for prophylaxis, treatment and prevention of relapse of malaria.

Malaria is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes. It is preventable and curable.

The first symptoms- fever, headache and chills-usually appear 10-15 days after the infective mosquito bite and may be mild and difficult to recognize as malaria.

Malaria, caused by 4 species of the protozoal parasite Plasmodium, is endemic in Zanzibar and other tropical countries. It is one of the major health problems

As per latest WHO estimate (2019), there were 229 million cases of malaria in 2019 compared to 228 million cases in 2018.The estimated number of malaria deaths stood at 409 000 in 2019, compared with 411 000 deaths in 2018.Children under 5 years of age are the most vulnerable group affected by malaria; in 2019 they accounted for 67% (274 000) of all malaria deaths worldwide.

The WHO Global technical strategy for malaria 2016-2030, updated in 2021, provides a technical strategy for all malaria-endemic countries;

• Reducing malaria case incidence by at least 90% by 2030
• Reducing malaria mortality rates by at least 90% by 2030
• Eliminating malaria in at least 35 countries by 2030
• Preventing a resurgence of malaria in all countries that are malaria free.

Malaria caused by 4 species of plasmodium parasite:

• Plasmodia Vivax
• Plasmodia Ovale
• Plasmodia Falciparam (severe malaria)
• Plasmodia Malariae

Classification of Antimalaria drugs:

1. 4-Aminoquinolines

Chloroquine (CQ), Amodiaquine (AM)

2. Quinoline-methanol

Mefloquine

3. Cinchona alkaloid

Quinoline, Quinidine

4. Biguanide

Proguanil

5. Diaminopyrimidine (Pyrimethamine)
6. 8-Aminoquinoline (Primaquine)
7. Sulfonamides and Sulfone

Sulfadoxine, Sulfamethopyrazine, Dapsone.

8. Antibiotic

Tetracycline, Doxycycline, Clindamycin

9. Sesquiterpine lactones

Artesunate, Artemether

10. Amino-alcohol

Lumefantrine, Halofantrine

11. Naphthyridine (Pyronaridine)
12. Naphthoquinone (Atovaquone).

Objectives and Use of Antimalaria Drugs:

1. To prevent clinical attack of malaria(prophylactic).
2. To treat clinical attack of malaria (clinical curative).
3. To completely eradicate the parasite from the parasite’s body (radical curative).
4. To cutdown human-to-mosquito transmission(gametocidal).

Chloroquine: It is a rapidly acting erythrocytic schizontocide against all species of plasmodia; control most clinical attacks in 1-2 days with disappearance of parasites from peripheral blood in 1-3 days.

Plasmodia digests hemoglobin to heme and globin. Globin is used by plasmodia for nutrition and heme being toxic to plasmodia is converted to non-toxic by heme polymerase enzyme of the parasite.

Chroquine raises the _PH and inhibit heme polymerase enzyme to convert of heme toxic to non-toxic for plasmodia. Chloroquine is an active against Entamoeba histolytica and Giardia lamblia as well.

It has anti-inflammatory, local irritant and anaethetics (on injection), weak smooth muscle relaxant, antihistaminic and antiarrhythmic properties.

Adverse effects: Toxicity of CQ is low, but side effects like nausea, vomiting, anorexia, uncontrolled itching, epigastric pain, uneasiness, difficulty in accommodation and headache are frequent and quite unpleasant. Weekly suppressive doses have been safely given for 3 years.

CQ can be used for treatment of malaria during pregnancy: no abortifacient or teratogenic effects have been reported.

Caution is to be exercised in the presence of liver damage, severe g.i., neurological, retinal and haematological diseases. Attacks of seizures, porphyria and psoriasis may be precipated.

CQ should not be coadministered with mefloquine, amiodarone and other antiarrthythmics.

Uses:

1. CQ causes rapid fever clearance and disappearance of parasitemia in patients of malaria caused by all ovale and P.malariae, most P.vivax and some P.falciparum that are still sensitive.It is the drug of choice for clinical cure of vivax, ovale and malariae malaria. However, its use for P.falciparum is restricted to few areas that still have susceptible.
2. Extraintestinal amoebiasis
3. Rheumatoid arthritis
4. Discoid lupus erythematosus-very effective
5. Lepra reaction
6. Photogenic reaction
7. Infectious mononucleosis, affords symptomatic relief.