A new capsule formulation of didanosine (Videx) has been launched by Bristol-Myers
Squibb (see p501).
The company says that the new formulation offers adherence advantages and improved
tolerability and is “the first one capsule, once daily antiretroviral”.
The new preparation, Videx EC, is a capsule containing enteric-coated beadlets
of didanosine. The enteric-coated formulation means that the buffer contained
in didanosine tablets is no longer required. Therefore, buffer-related side
effects and drug interactions which occurred with didanosine tablets will not
be a problem with the new formulation, the company says. It adds that, as a
result, didanosine EC capsules can be taken with indinavir. Bristol-Myers Squibb
says that didanosine EC capsules are bioequivalent to didanosine tablets. Four
strengths are available: 125mg, 200mg, 250mg and 400mg. Videx EC will be available
at the same price as Videx tablets.
In a press statement issued by Bristol-Myers Squibb, Ms Rosy Weston (senior
HIV pharmacist, St Mary’s hospital, London) said: “Many patients find
it difficult to adhere to complex multi-drug regimens. The development of Videx
EC is welcomed by pharmacists, as it allows once-daily dosing with a single,
easy to swallow capsule, avoiding problems associated with the taste of the
tablet formulation.”
Miss Sian Lloyd (virology products manager, Bristol-Myers Squibb, UK) told The
Journal on September 25 that didanosine tablets would be discontinued through
natural decline, unless market forces were to dictate otherwise.
She added that there had been some confusion over the dosing of didanosine 200mg
tablets following the publication of a study which showed that twice-daily dosing
of didanosine might be preferable to once-daily dosing (PJ, August 19, p259).
Didanosine 200mg tablets could only be used as part of a once-daily regimen,
she said. This was because the maximum daily dose for didanosine was 400mg and
because all doses had to be given as a minimum of two tablets so that a sufficient
dose of antacid, also contained in the tablet, was obtained. The new formulation
of didanosine overcame this problem because it did not need to contain an antacid
(because of the enteric coating) so only one capsule had to be taken for each
dose.