The influence of botulinum toxin A type 1 (BTA) dose on the efficacy of therapy in patients with neurogenic and idiopathic detrusor overactivity was studied and the incidence of urinary difficulties in the early period after botulinum therapy was studied. It was found that BTA-therapy in all patients led to a significant improvement in the state of urination, a decrease the frequency of urination, episodes of urinary incontinence, and improve all parameters of a complex urodynamic study.

The therapeutic effect lasted from 6 to 30 months: up to >9 months. in 74% of cases; >1 year - in 52%; >1.5 years - in 17% and 2.5 years - in 8.6%. In patients with neurogenic detrusor overactivity, the duration of improvement in urination ranged from 6 to 14 months, regardless of the dose of BTA, in the range of 200-300 ED. In patients with idiopathic detrusor overactivity with a BTA dose of 100-200 ED, in more than 50%, the improvement in urination was maintained for at least one year, whereas at a higher dose, the duration of the effect did not exceed 10 months in all patients.

The incidence of urinary difficulty increased with an increase in the dose of BTA. If patients who received less than 200 units of BTA did not show an increase in the volume of residual urine >200 ml in either case, then at a dose of200 units it was noted in 8.3% of patients, at 250 units in 19.2 %, at 300 ED - in 27,8% of cases. The periodic catheterization of the bladder at a dose of BTA up to 200 units did not occur in any of the patients, at 250, 300 units. - originated 15.4% and 22.2% of cases respectively. This complication in all patients was resolved spontaneously within 2 weeks and did not lead to the need for additional therapeutic measures.

Given the lack of an increase in the effectiveness of treatment with high doses of BTA and a more frequent development of urinary difficulty in these patients, we recommend using the lowest possible dose of BTA to achieve the optimal "efficiency / safety" ratio: 100 units - for idiopathic detrusor overactivity and 200 AD - for neurogenic detrusor overactivity.

Authors declare lack of the possible conflicts of interests.