Safety Issues Stall Philippines Dengue Herbal Trial

A controversial trial of herb-derived treatments for dengue has been stalled amidst ethical and drug-resistance concerns.

AsianScientist (Mar. 5, 2015) – By Anna Valmero – Philippine health officials are set to announce next month their findings on a controversial research on dengue treatment suspended since November on concerns that protocols were not followed after it was discovered it was tested on humans.

The findings will determine if suspension on clinical trials due to safety issues will be lifted or not, says Lyndon Lee Suy, spokesperson for the Department of Health (DOH).

The ActRx TriAct anti-dengue treatment is a combination of sublingual spray (for the tongue) of artemether and tablets of berberine and artesunate. An initial 500 sets of the combo treatment from the US non-profit organisation ActRx Foundation were used for trials on 200 patients in six government hospitals in October 2014.

But DOH Acting Secretary Janette Garin ordered the suspension a month later, citing lack of scientific evidence and the potential complication of developing malaria resistance to artemether.

Derived from artemisinin, plant-based artemether, in combination with two other drugs, lumifantrine and primaquine, remains the only effective treatment against the deadliest form of malaria caused by Plasmodium falciparum.

However, the WHO does not recommend treating dengue with single or combined derivatives of artemisinin because “resistance to malaria could emerge,” WHO representative to the Philippines Julie Hall tells SciDev.Net.

In South-East Asia, cases of malaria from Cambodia, Myanmar, Thailand and Vietnam have started developing resistance to artemether. These countries were noted to administer artemether in monotheraphy when it requires to be combined with lumifantrine and primaquine to be effective against malaria.

Likewise, the DOH review committee said the ActRx component berberine raised questions on safety because it was not scientifically studied before it was used as an experimental drug on Filipinos.

“The use of the herbal medicine called berberine for dengue management needs more extensive analysis. At present, there is no plausible mechanism available for its use against malaria and dengue,” explains Suy, who is also a member of the review committee.

Minerva Calimag, president of the Philippine Medical Association, notes that drug development is a long four-phase process and no steps should be skipped.

The 200 patients in the clinical trials is “a small sample to guarantee that no side effects will occur when the drug is used in a larger number of patients,” adds Calimag.

The Philippine Council for Health Research and Development (PCHRD) cited the lack of ethics review for patient protection based on the missing baseline characteristics of the patients and the lack of pre-clinical trials.

Enhancements on future research should strictly follow proper scientific protocols, including increasing the number of cases and patients, recommends PCHRD chief Jaime Montoya.

Research for public health should always prioritise safety, explains Fely Marilyn Lorenzo, professor at the University of the Philippines Manila and member of the SEAMEO Tropical Medicine Regional Center for Public Health.

Lorenzo says that the case of ActRx highlights the weaknesses in Philippine medical research and should prompt officials to improve mechanisms and processes for drug development on tropical diseases such as dengue.


Source: SciDev.Net.
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