In the new study, researchers found that a class of HIV drugs improved the effectiveness of lumefantrine, a key malaria drug.
The study tested two anti-retroviral “cocktails” on 170 HIV-positive Ugandan children under the age of five. One of the cocktails contained two protease inhibitors — lopinavir and ritonavir, which for long were established to creep the germ that causes malaria.
Over the course of the two-year trial, children, who received the drug cocktail containing the inhibitors, had a 41 per cent reduction in malaria cases compared with children who did not.
To their surprise, the researchers found that that one protease inhibitor did indeed reduce the number of malaria cases in the group of children which took it, but not in the way they had imagined. They found that the two protease inhibitors had a limited impact on the malaria parasite itself. However, they found that one of the inhibitors — ritonavir — boosted the longevity in the body of a widely used anti-malarial drug, lumefantrine.
Interestingly, the researchers found that in the group of children who had taken lumefantrine on account of their first episode of malaria attack, recurrent malaria bouts were dramatically reduced by as much as 59 per cent.
Lumefantrine, unlike artemether, is known to remain within the body for several weeks, and researchers speculated that the ritonavir might have limited the liver’s ability to remove it from the system, thereby extending its protective effects.
Children, who received anti-retroviral cocktails containing ritonavir, had five times as much lumefantrine in their bodies a week after receiving the antimalarial.
Conversely, they suggested in the presentation of the study at the 19th Conference on Retroviruses and Opportunistic Infections that these higher lumefantrine exposures were really factors driving the protection against recurrent episodes of malaria.
Dr Catherine Falade, Acting Head, Department of Pharmacology and Therapeutics, University of Ibadan, Oyo State, stated that the finding was most useful in HIV individuals considering the fact that once their CD4 count is low, there immunity becomes bad compromised and thus making them more susceptible to all sorts of infections, including malaria.
“Malaria is particularly relevant in Africa because it is hyper-endemic. The finding of this clinical study, which was carried out on children with HIV, who were being given HIV-cocktail containing protease inhibitors, and stating that they had significantly fewer reoccurrences of malaria when treated with arthemeter and lumefantrine, is a welcome one.
“Due to the immune compromise nature of HIV infected children; the regular antimalarial doses might not be enough to deal with the ordinary malaria because usually, the body’s immunity adds on to the efficacy of the antimalarial drug.
“The lumefantrine is broken down in the liver by enzymes and so if the enzyme to break this drug down which is part of the recommended ACT therapy used in the treatment of malaria is inhibited, obviously, it will lead to a prolonged presence of lumefantrine in the blood stream.
“For as long as the blood level of lumefantrine is above normal concentration, this allows for a superior clearance of malaria-causing germ, and hence, ensure more effectiveness. The consequence of this is that the children are more likely to be totally cured of all germs that cause malaria in their body.
“For instance, the findings that children taking HIV-cocktail containing protease inhibitors had significantly longer intervals between their malaria episodes indicated that the HIV drug had some element of prophylaxis. This, no doubt, is a useful drug-drug interaction.
“It is not all drug-drug interaction that is bad. In actual fact, in clinical pharmacology, effects of some drug-drug interactions are used for routine treatment of medical conditions.
How applicable is this finding in Nigeria’s HIV-infected children? According to her, there is a whole lot of things that go into ARV therapy such as the cost and availability of these drugs that would influence any change in drug policy.
She declared: “HIV-cocktail containing protease inhibitors are not available in treatment centres and as such, HIV patients will still be better off receiving whatever ARV therapy that they are currently being offered. Of course, with the ARV therapy they are provided, once their CD4 count rises, their body immunity picks up and so they are less prone to malaria.
“The standard procedure of HIV therapy regime varies from one ARV clinic to another. These are guidelines and factors that help determine the ARV combination treatment that should be given to different HIV-infected individuals.
Drugs are currently not widely used in malaria prevention, with preventive efforts traditionally focused around mosquito nets and insecticides. Bed nets remain the most critical prevention strategy for malaria.
Persistent malaria infections were linked to anaemia in many African children, and so the anti-retroviral combination might reduce it.
Source:tribune
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