Efficacy and tolerability of piroxicam-beta-cyclodextrin in the outpatient management of chronic back pain

BACKGROUND

Piroxicam-beta-cyclodextrin (PBC) is the first nonsteroidal anti-inflammatory drug (NSAID), in which the active substance is complexed with the cyclic oligosaccharide cyclodextrin, which acts as an artificial receptor. This complex allows single molecules of the NSAID to be released adjacent to the gastrointestinal mucosa, instead of crystals. Since the piroxicam is immediately bioavailable in this formulation, the onset of action is similar to that of a parenteral drug. Since the time contact with gastric mucosa is reduced, the risk of direct-contact gastric irritation is also reduced. There is good evidence that PBC is beneficial in managing acute non-specific back pain (BP) but sufficient evidence on chronic BP is lacking.

METHODS

Thirty-one eligible patients aged 18-85 years, resistant to previous therapy with different NSAIDs, were treated with PBC 20 mg once daily in a 40-day open-label noncomparative study. The patients experienced chronic BP defined as pain between the occipital region and gluteal fold, lasting for at least 6 weeks but not more than 6 months. Efficacy was assessed by changes in pain intensity, paravertebral tonus, functional impairment and morning stiffness using a 4-point numerical rating scale. Patients also self-assessed nocturnal and diurnal pain using the visual analogue scale. Tolerability was assessed by adverse events and routine laboratory evaluations. Global assessment of efficacy and tolerability by physician and patients was performed at the last visit.

RESULTS

Using intention-to-treat analysis, all efficacy assessments demonstrated statistically significant improvements over baseline at each follow-up. 90.3% of the patients evaluated the efficacy of PBC as improved or greatly improved, and investigators rated the treatment as improved or greatly improved in 87.1% of patients. Remission was achieved in 19.3% of the patients. Tolerability was also rated highly, with 83.9% of the patients characterizing PBC treatment as good or very good, and the investigators rated the treatment as good or excellent in 87.1% of the patients. Drug related adverse events were reported in 9.7% of patients and prompted discontinuation of the study medication in 3.2% of patients. No serious adverse events were reported.

CONCLUSION

These results suggest that the newly developed dosage form of piroxicam is effective and well tolerated in the treatment of patients with chronic BP. Thus, PBC, may be an important new treatment option in this condition. (Tab. 3, Fig. 3, Ref. 36.).

Experimental live tick-borne encephalitis vaccine (Labgat E5 "14" virus clone): volunteers 1 and 2 years after single-dose immunization

Groups of volunteers given intramuscularly 5 or 6.5 dex or perorally 6.5 dex newborn mouse icLD50 of the plaquesegregated "14" clone of the Langat E5 virus strain (tick-borne encephalitis comples) were followed for periods of 12 and 24-27 months. Circulating specific virus neutralizing antibodies persisted in them in the absence of apparent reaction as evidenced by clinical, electroencephalographic and cerebrospinal fluid findings.