Co-dydramol

Co-dydramol is a non-proprietary name used to denote a particular compound analgesic, a combination of dihydrocodeine tartrate and paracetamol. Co-dydramol tablets are used for the relief of moderate pain. Co-dydramol is part of a series of combination drugs available in the UK and other countries including co-codaprin.

Formulations

All formulations of co-dydramol contain 500 mg of paracetamol per tablet and may only be sold at a pharmacy as an over-the-counter item without prescription if containing less than 7.5 mg of dihydrocodeine per tablet. Higher strengths are prescription only medicines. There are no GSL formulations of co-dydramol, as it is a Schedule 5 controlled drug. Four strengths of dihydrocodeine tartrate in each tablet are available:

7.46 mg dihydrocodeine as co-dydramol 7.46/500.
10 mg dihydrocodeine as co-dydramol 10/500, this is also the preparation to be dispensed if no strength is specified on a prescription.
20 mg dihydrocodeine as co-dydramol 20/500.
30 mg dihydrocodeine as co-dydramol 30/500.

Metabolism

Dihydrocodeine is metabolised by the CYP450 system isoenzyme 2D6 to dihydromorphine, which mediates the majority of its analgesic effects. Owing to the low oral bioavailibility of dihydrocodeine, and its subsequent metabolism to active compounds, it is likely that doses below 30mg are sub therapeutic for analgesia.