The European Union's drug licensing body has approved a new formulation of ddI (didanosine) designed to cut down the number of tablets and make the drug easier to tolerate.
The new formulation comes in a capsule to be taken once a day, at least half an hour before eating or on an empty stomach. The capsule coating protects the drug from being broken down by acid in the stomach, eliminating the need for an antacid buffer. The buffer is what makes ddI tablets bulky, and it can also cause diarrhoea and other gastrointestinal problems. Interactions between the buffer and indinavir, ketaconazole and ciprofloxacin are also eliminated in the new formulation.
The encapsulation of ddI also cuts out the need to dissolve tablets in water, thus eliminating the need to taste the drug.
The new formulation, called Videx-EC, is already available in the UK on a named patient basis for anyone who can't tolerate the existing tablet formulation of ddI, or for anyone failing on an existing regimen, or for anyone who is starting treatment. The drug will be available on prescription throughout Europe from late September onwards. It is the second once-daily anti-HIV drug, following efavirenz.
The approval comes just months after Bristol-Myers Squibb introduced reduced mass ddI tablets containing less buffer, so that ddI could be dosed once daily in the form of two 200mg tablets.