Oxybutynin pour les bouffées de chaleur

J'ai un patient qui présente des bouffées de chaleur importantes et pour qui le md a prescrit de l'oxybutynin. Aucune indication officielle ou non-officielle pour cette indication dans Vigilance.

Par contre, j'ai trouvé deux études dans Pub Med:

http://www.ncbi.nlm.nih.gov/pubmed/17204995

2007 May-Jun;

Oxybutynin for refractory hot flashes in cancer patients.

OBJECTIVE:

There is little information available on the treatment of hot flashes in patients refractory to pharmaceutical interventions. Anecdotal evidence led to the use of oxybutynin for the management of hot flashes in refractory cancer patients; therefore, we performed a retrospective chart review of such patients to determine the effect of oxybutynin in treating hot flashes and to observe the side effects of the drug in these patients.

DESIGN:

A prospective database of all patients treated for hot flashes was started in July 2004 and was retrospectively analyzed as of March 2006. Also included were individual charts preceding July 2004. Fifty-two patient charts were examined. Demographic information was obtained along with baseline severity and frequency of hot flashes, dose and duration of treatment with oxybutynin, patient response to oxybutynin, and side effects.

RESULTS:

More than 90% of patients analyzed were refractory to hot flash treatments before starting oxybutynin. Seventy percent of patients showed a partial or excellent response to oxybutynin. The duration of oxybutynin use ranged from 2 weeks to 5 years with more than half of patients currently on oxybutynin or taking oxybutynin for longer than 6 months. Of those patients who experienced an excellent or partial response to treatment, 12% stopped because of documented oxybutynin-related side effects within 4 weeks.

CONCLUSION:

Oxybutynin seems promising in the management of hot flashes with tolerable side effects in the majority of refractory patients. A placebo-controlled, randomized study is being developed to look more closely at the effectiveness of oxybutynin in reducing hot flashes.

http://www.ncbi.nlm.nih.gov/pubmed/22377187

2012 May

Effective and clinically meaningful non-hormonal hot flash therapies.

Although many non-hormonal compounds have shown statistically significant benefit over placebo in hot flash randomized controlled trials (RCTs), these studies have varied considerably in basic methodology making it challenging to deduce which compounds have the greatest potential to provide clinically meaningful benefit. This review used evidence-based methodology closely mirroring the FDA and EMEA guidelines as a template to identify "well-designed" RCTs from which effective and clinically meaningful non-hormonal hot flash therapies could be identified. In addition, pertinent safety information was reviewed. Out of 3548 MEDLINE citations and abstracts, 51 well-designed hot flash RCTs were identified. From these trials, gabapentin, oxybutynin ER, desvenlafaxine, soy-derived isoflavones and black cohosh each showed a clinically meaningful treatment effect in at least 1 RCT. Among these 5 compounds, only gabapentin demonstrated consistent and statistically significant benefit over placebo in all of its well-designed RCTs. Desvenlafaxine, soy-derived isoflavones, and black cohosh demonstrated statistically significant benefit over placebo in 75%, 21%, and 17% of the well-designed RCTs for each compound, respectively. There was only 1 well-designed RCT using oxybutynin ER, which showed it to have a robust and clinically meaningful benefit. In terms of safety, there have been cardiovascular risks associated with desvenlafaxine use in postmenopausal women with hot flashes. The use of anticonvulsants, in general, has been associated with an absolute 0.21% increase in suicidal thoughts and behavior. Further research is needed with several of these nonhormonal compounds to replicate these findings and to also directly compare their efficacy and tolerability with those of hormone replacement therapy.