This randomized, double-blind, multi-centre study was undertaken to evaluate the efficacy and safety of treatment for 4 weeks with
codeine plus
paracetamol versus
paracetamol in relieving
chronic pain due to
osteoarthritis of the hip. A total of 158 outclinic patients entered the study. Eighty-three patients (mean age 66 years) were treated with
codeine 60 mg plus
paracetamol 1 g 3 times daily, and 75 patients (mean age 67 years) with
paracetamol 1 g 3 times daily.
Ibuprofen 400 mg was prescribed as rescue medication. Due to an unexpected high rate of
adverse drug reactions, the study was closed before the planned 400 patients had entered. Over weeks 1-4, 87%, 64%, 61% and 52% of patients in the
codeine plus
paracetamol group, and 38%, 31%, 22% and 29% of patients in the
paracetamol group had one or more
adverse drug reactions. Significantly more patients in the
codeine plus
paracetamol group had
adverse drug reactions in each of the 4 weeks.
Nausea,
dizziness,
vomiting and
constipation were predominant adverse reactions in the
codeine plus
paracetamol group. During the first week of treatment, 30 patients (36%) in the
codeine plus
paracetamol group and 9 (12%) in the
paracetamol group dropped out. As evaluated from patients completing the first week of treatment, the
pain intensity during that week compared to their baseline
pain was significantly lower in the
codeine plus
paracetamol group than in the
paracetamol group. Moreover, during the first week the
paracetamol group received rescue medicine significantly more frequently. In conclusion, when evaluated after 7 days of treatment, the daily addition of
codeine 180 mg to
paracetamol 3 g significantly reduced the intensity of
chronic pain due to
osteoarthritis of the hip joint. However, several
adverse drug reactions, mainly of the gastrointestinal tract, and the larger number of patients withdrawing from treatment means that the addition of such doses of
codeine cannot be recommended for longer-term treatment of
chronic pain in elderly patients.