Clinical and circulatory effects of Iloprost either administered for 1 week or 4 weeks in patients with peripheral obstructive arterial disease at Leriche-Fontaine stage III.

BACKGROUND

Iloprost therapy for severe peripheral obstructive arterial disease (POAD) has demonstrated to be effective in reducing the need for amputation. However the feasibility of a 28-day infusion regimen in less severe stages of the disease is poor due to the length in hospital stay. A randomized, controlled, parallel-group pilot study was carried out with the aim to evaluate clinical and circulatory effects of Iloprost, a stable prostacyclin analogue, administered with two different infusion schedules to patients with POAD at Leriche Fontaine stage III.

METHODS

Twenty patients 16 males and 4 females, mean age 66 +/- 6 years) with objective signs of POAD, rest pain for at least two weeks and posterior tibial artery pressure > 50 mmHg, were randomized to either Iloprost i.v. infusion up to 2 ng/Kg/min for 6/h/day for 28 days (Group A) or to Iloprost i.v. infusion up to 1.5 ng/Kg/min for 16/h/day for 7 days (Group B). At baseline (before starting first infusion) after 7 days (for group B only, end of therapy) and after 28 days (end of therapy for Group A, end of study for Group B) the following parameters were evaluated: walking distance, rest pain and analgesic consumption, plethysmographyc parameters (first flow, peak flow and peak flow time) and laser Doppler parameters (rest flow, post ischemic flow).

RESULTS

After 28 days, both Iloprost infusion schedules increased walking capacity (maximum walking distance/pain free walking distance +119/+84% +199/+85% respectively, for Group A and B respectively) reduced ischemic pain (-45% and -48% respectively for Group A and B) and analgesic consumption and improved plethysmographyc and laser Doppler parameters. Tolerability seemed to be better in Group B, suggesting that the lower dose and the shorter duration of the therapy period might result in reduced incidence of headache thus, in principle, increasing patient acceptability.

CONCLUSIONS

The results of this pilot study, if confirmed by larger trials, could have important positive implications in terms of costs, patient comfort and management.