Malaria is a treatable endemic disease prevalent in the tropics and subtropics, graphically positioned around the equatorial zone such as countries in the region of Africa, Central and South America, Dominican Republic and Haiti.
Although a curable disease condition, there still remains a challenge in access to timely accurate treatment resulting in fatalities, recurrent and resistant forms of malaria for countries with economic constraints and resistant parasites. According to WHO (World Health Organization) from the 219 million malarial cases in 2017, the African region contributed to 92 per cent of those cases.
Guyana contributes to a mere three per cent of the current total global incidences which quantify to about 20,000 cases annually. In a 2016 local publication, it was established that the national index spiked over the past three decades due to movement of the mining populations in southern Guyana, from the Rupununi to Cuyuni/ Mazaruni/ Potaro, in the north western region of Guyana. Currently five out of the ten administrative regions in the hinterland are affected.
The female anopheles mosquitos are responsible carriers for the malarial parasite, which thrive in hot humid conditions. Generally temperature, humidity and rainfall are the three climatic conditions, which create a good breathing ground for all types of mosquitos, as can be noticed with the current record rainfall we have been experiencing in Guyana, more pronounced in Regions Three, Seven, Eight and10. Infected humans are also transmitters for the malarial parasite, so impregnated mosquito nets and mosquito repellants are key methods of prevention.
Two species of the malarial parasite identified are the plasmodium vivax, mostly occurring in ambient or cooler climatic conditions, and the plasmodium falciparum found in warmer conditions. Both p. falciparum and p. vivax are present in Guyana, where the former is more pronounced due to our higher climatic temperature. Sometimes persons can have mixed infections due to the invasion of both causative agents.
The gold standard diagnostic confirmatory test is the blood smear but since time is a key success factor for treatment rapid diagnostic tests are used if available. The thick blood smear is differentiated from the thin blood smear where the former is used for detecting the presence of the parasite, whilst the latter details the causative species or the type of malaria. A PCR test may be considered only if such resources are immediately accessible.
The four screening considerations before the initiation of treatment are identifying the type of malarial parasite, establishing the severity of the symptoms, the age of the patient and the pregnancy status, if it is a female patient. The National Treatment Guidelines of Guyana incorporates four main anti-malarial drugs in its treatment protocols for uncomplicated malaria namely chloroquine, artemether/lumefantrine, primaquin and quinine. However, it must be noted that a high global resistance is seen with chloroquine.
Artefan, is one of the branded antimalarial two-in-one drug, containing 20mg artemether and 120mg lumefantrine. It is prescribed only for selected categories of patients in the treatment of uncomplicated malaria. These categories indicated for Artefan use are in P. falciparum infected children, adults or late stage pregnant mothers (second and third trimester), in conjunction with other medications. Additionally, it can also be used in mixed infections in various grouping such as falciparum plus vivax, falciparum plus malariae and falciparum plus vivax plus malariae.
Artefan has a rapid absorption, where the peak plasma concentration is two hours after administration, in the bioavailable form or artemether as DHA (dihydroartemisinin), having been through first pass metabolism.
The dosage of Artefan depends on the age of the patient and the body weight. The minimum dosage for uncomplicated p. falciparum in a child three years of age is a total of six tablets to be used in the course of treatment over a three day period.
For a child with body weight between 5kg to 15kg one tablet immediately after diagnosis followed by the second dose eight hours after then subsequently four doses 12 hours apart. As the weight of the patient increases so does the dose; so between 15kg to 25kg the dosage will be two tablets at the same interval, between 25kg to 35kg the dosage is three tablets at the same interval and above 12 years of age or an adult dosage is four tablets at the same interval. So the total course for an adult is 24 tablets to be taken over the three-day period, which explains the way it is packaged.
A single dose of primaquin, where the dose also varies with age and body weight, is used in conjunction with the Artefan. So a minimum of half tablet for a six-month-old baby to a maximum of three tablets for adults with more than 50kg.
Note that Artefan is not listed in the National Treatment Guidelines for uncomplicated p. vivax nor p. malariae but is recommended in mixed infections where p. falciparum is present. It is also safe for use in the second and third trimester in pregnancy, if the benefits outweigh the risks.
Apart from hypersensitivity reactions such as allergies to any of the active or inactive ingredient, there are certain pre-existing conditions about which you are advised to inform the medical practitioner before treatment with this drug is decided upon.
These conditions are abnormal ECG readings, hypokalemia (low potassium in the blood), bradycardia (slow heart rate), heart failure or arrhythmias (irregular heart rhythm). Or if you are on medications like diuretics (water pills) which have the ability to cause hypokalaemia or other heart medications to affect the heart rate like beta blockers (atenolol, metoprolol and propranolol) and antiarrhythmic drugs, you are advised to inform the physician.
For further pharmacological guidance, contact the pharmacist of Medicine Express PHARMACY located at 223 Camp Street, between Lamaha and New Market Streets. If you have any queries, comments or further information on the above topic kindly forward them to medicine.express@gmail.com or send them to 223 Camp Street, N/burg. Tel #225-5142.