Paracetamol as a prophylactic analgesic for hysterosalpingography: a double blind randomized controlled trial

To evaluate the effectiveness of paracetamol as a prophylactic analgesic for hysterosalpingography (HSG).

A prospective double blind randomized controlled trial comparing one 1 g of paracetamol (SmithKline Beecham, Brentford, U.K.) to placebo taken 30 min before HSG. One hundred consecutive out-patients were studied prospectively. The analgesic effectiveness during the procedure and at 24 h and 1 week post procedure was analysed by a postal pain score questionnaire. Additional data on the ethnicity of the patient, sex and level of experience of the radiologist performing the hysterosalpingogram, the parity of the patient, the ease of the procedure, and whether pathology was identified were also recorded.

Eighty-eight patients (88%) replied, 39 (44%) received paracetamol and 49 placebo (56%). During the procedure 3/39 (7%) of women in the paracetamol group were pain-free compared to 9/49 (18%) in the placebo group, which was not significant (P = 0.11). At 24 h, 15/39 (38%) of women in the paracetamol group were pain-free compared to 20/49 (41%) in the placebo group, which was not significant (P = 0.82). At 1 week, 27/39 (69%) of women in the paracetamol group were pain-free compared to 29/49 (59%) in the placebo group, which was not significant (P = 0.33). No significant difference in mean pain scores was determined during the procedure (P = 0.91), or at 24 h post procedure (P = 0.94). Similarly, no difference in mean pain scores was identified with regard to the ethnicity of the patient, the sex of the radiologist performing the procedure, the level of experience of the radiologist performing the procedure, or whether pathology was present or not. Difficult cannulations were associated with higher mean pain scores, however, there was no difference in mean pain scores between the paracetamol or placebo groups for both easy and difficult cannulations.

Paracetamol is not effective as a prophylactic analgesic for HSG. If a prophylactic analgesic is considered necessary for pain relief during HSG we recommend that a non-steroidal anti-inflammatory drug (NSAID) is used.