Authors

Year

Study type

N

Notable findings

Parsons [2]

1983

Pilot, open label

24

22 of 24 patients (91.6%) reported symptom improvement

Parsons [1]

1984

RCT crossover

47% of patients in treatment arm improved; 23% favorable response in placebo group

Parsons and Mulholland [5]

1987

RCT cross over

62

Increased voided volumes; subjective improvements in urge, frequency, pain, nocturia

Termination of drug resulted in symptom return within 3 to 12 weeks in 80%

Holm-Bentzen et al. [6]

1987

RCT

115

No clinically significant differences in symptoms, urodynamic parameters, cystoscopic appearance and mast cell counts

Fritjofsson et al. [7]

1987

Open label

87

Improvement in urinary frequency and voided volumes in non HL patients. These improvements were not seen in those with HL

Pain improved in both groups and this effect was stable at the 3-month follow up

Mulholland et al. [8]

1990

RCT

110

Overall improvement of greater than 25% was reported by 28% of the PPS-treated patients and by 13% of those treated with placebo. (p = 0.03)

Parsons et al. [9]

1993

RCT

148

32% of those receiving PPS showed significant improvement compared to 16% of those on placebo (p = 0.01)

Patients on PPS experienced a significant decrease in pain and urgency (p = 0.04 and 0.01) compared to placebo

More subjects on PPS showed an average increase of more than 20 ml in voided volume than did placebo patients (p = 0.02)

Hanno [1]

1997

Prospective, long term, open label compassionate use

2809

46% of patients dropped out within first 3 months

42–62% of patients receiving PPS had moderate or better symptom improvement

Jepsen et al. [11]

1998

Retrospective, long term compassionate use

97

11.3% of patient continued PPS for more than 18 mo.

Correlation of increased PPS duration of treatment to less constant pain

Sant et al. [12]

2003

RCT

60

A non-significant trend in improved global response assessment was seen in PPS group (34%) versus placebo (18%); p = 0.064

2×2 factorial study of PPS and hydroxyzine

Nickel et al. [13]

2005

Randomized, double blinded, dose ranging study

380

230 patient completed study

Mean ICSI scores and PORIS improved for 300, 600, and 900 mg dosages; improvements were not dose dependent

Symptom response appeared to improve with longer courses of therapy

Nickel et al. [14]

2008

Retrospective

128

Patients receiving therapy soon after diagnosis may do better clinically

Davis et al. [15]

2008

RCT

41

Oral PPS demonstrated 24% reduction in symptom scores as compared to combined oral PPS and intravesical PPS (46% reduction) at 12 weeks

Al-Zahrani et al. [16]

2011

Retrospective/long-term

271

34.3% drop out

Better results in those with significant glomerulations

Trend toward better response in >12 mo group

Nickel et al. [17]

2015

RCT

368

44% dropout

No difference between placebo, PPS 100 mg, PPS 300 mg dosing for primary endpoint at 24 weeks

No difference in symptom improvement between PPS naïve and non naïve patients

Subgroup analysis of IC/BPS patients meeting NIDDK criteria demonstrated highest response in placebo group (50%)