M. Scherer
November 8, 1996
A 65-year-old male presents with long-standing pain in his hips, thighs and calves associated with walking and relieved with rest. His pain has notably increased over the past year, now to the point that he has difficulty going shopping. Past medical history is remarkable for hypertension and cigarette smoking. On physical exam, there are bilateral femoral bruits and markedly diminished distal lower extremity pulses. He is informed of his diagnosis of PVD and asks if there is any medicine to help with his symptoms.
1.) Pentoxifylline significantly improved walking distances in the study
population. During weeks 16 to
24, the mean improvement in absolute distance was 50+8% for Pentoxifylline and 26+7% for
placebo
(p-.02). In practical terms, the walking distance could be expound to improve 80-100
meters (1.1-1.3
city blocks) above placebo.
2.) A target population, defined as patients with ABI<0.8 and symptoms >1 year,
particularly benefited
from Pentoxifylline. This group represented 73% of study patients.
3.) In the target population, 11 initial and absolute claudication distances measured
improved with
statistical significance and with greater magnitude than the overall study population.
Double-blind randomized controlled trial of 150 patients treated with either pentoxifylline or placebo.
| Initial claudication distance Absolute claudication distance Absolute claudication distance | ||||||
| Pentoxtfylline
Placebo
p
Pentoxifylline
Placebo
p (n=76) (n=74) (n=76) (n=74) |
||||||
| Weekly measures | ||||||
| Baseline distance Percent Improvement |
77+/-4 |
79+/-4 |
0.613 |
132+/-9 |
155+/-11 |
0.042 |
| LOCF to week 20 | 74+/-11 |
56+/-11 |
0.233 |
46+/-8 |
24+/-7 |
0.031 |
| LOCF to week 24 | 80+/-12 |
60+/-11 |
0.268 |
50+/-9 |
29+/-8 |
0.094 |
| Summary measures | ||||||
| Minimum of wk 16-24 | 54+/-10 |
27+/-8 |
0.060 |
31+/-8 |
9+/-6 |
0.023 |
| Mean of wk 16-24 | 79+/-11 |
57+/-10 |
0.101 |
50+/-8 |
26+/-7 |
0.021 |
| Median of wk 16-24 | 82+/-12 |
60+/-10 |
0.134 |
51+/-9 |
26+/-7 |
0.011 |
Values are geometric mean + SEM LOCF, Last observation carried forward.
1.) Cost for pentoxifylline~$35/month..
2.) Adverse events - 22% receiving pentoxifylline and 14% taking placebo reported side
effects. These were mild and did not lead to exclusion. The most frequent was nausea (13
patients -pentoxifylline, 7 patients-placebo, p=ns).
2.) Diabetic patients (who normally represent a large proportion of PVD patients) were
excluded.
3.) Details on patient follow-up (i.e. missed visits) and the extent of physician-patient
counseling was not well documented in the present study. Similarly, prior studies of
pentoxifylline also show this lack of information,according to meta-analysis data.
Lindgarde, F., et. al. Conservative drug treatment in patients with moderately severe
chronic occlusive
peripheral arterial disease. Circulation 1989; 80: 1549-1556.
Radack, Kenneth and Wyderski, R.J. Conservative management of intermittent claudication. Annals
of Internal Medicine 1990; 1 13: 135-146.