Safer sleeping sickness treatment

Issued: Tue, 10 Jan 2012 09:09:00 GMT

Sleeping sickness is endemic in 36 sub-Saharan countries, exposing 60 million people to the risk of infection. Transmitted by the tsetse fly and caused by the trypanosome parasite it is invariably fatal if left untreated. It is estimated that around 30,000 people at least are currently infected. Infection can last from several weeks to years before it crosses the blood-brain barrier and causes brain inflammation and swelling, always resulting in death if left untreated.

Once the disease has crossed the blood-brain barrier and entered the central nervous system the most commonly used treatment is an intravenous course of the arsenic-based drug melarsoprol. Treatment is protracted, excruciatingly painful and, due to the toxicity of the drug, kills one in 20 patients.

Glasgow Professor Peter Kennedy explains: 'Because melarsoprol has a low solubility in water, it is dissolved in propylene glycol and administered intravenously. The result is a highly toxic drug that kills 5% of patients receiving it and leaves many others permanently brain-damaged.'

Researchers in the University's Institute of Infection, Immunity & Inflammation have created a safer version of the drug that could be administered in a pill. They combined melarsoprol with cyclodextrins: molecules that surround the drug, allowing it to be administered orally; increasing its solubility and releasing the drug more slowly in the gut.

'Melarsoprol is very effective at killing the parasites but when given intravenously it probably does this too quickly, which is in part why we think it is so dangerous,' explains Professor Kennedy, who is leading the research which is funded by the Medical Research Council. 'By controlling the rate of release of the drug with this new oral formulation, we believe we make it safer.

'This new research is the most clinically important in the 20 years of our trypanosome research group. It has the potential of a major therapeutic advance and would also have a significant socio-economic impact because the duration of inpatient treatment would be shorter and some patients might even be eventually treated at home.'

The researchers hope to secure more funding in order to progress to trials in Uganda in around 18 months.

Find out more

• Professor Peter Kennedy
• Institute of Infection, Immunity and Inflammation
• College of Medical, Veterinary and Life Sciences