hypericum and Polyneuropathies

Painful polyneuropathy is a common neuropathic pain condition. The present study describes health-related quality of life (HRQL) in a sample of patients with painful polyneuropathy of different origin and the possible predictive role of HRQL for analgesic effect. Ninety-three patients with a diagnosis of painful polyneuropathy were included in the analysis. Data were obtained from three randomised, placebo-controlled cross-over studies testing the effect of different drugs on polyneuropathic pain (St. John's wort, venlafaxine/imipramine and valproic acid). Patients completed a HRQL questionnaire (SF-36) after a drug-free baseline period and at the end of each treatment period. At baseline, all eight SF-36 scores were lower than in the normal population. No significant differences were found between SF-36 scales during placebo and treatment with valproic acid and St. John's wort. Those two drugs had not shown a pain relieving effect in former analysis. The SF-36 scale of bodily pain (BP) was improved by venlafaxine treatment (p=0.023). General health (GH) and vitality (VT) were improved under treatment with imipramine (GH: p=0.006, VT: p=0.015). In a multivariate logistic regression analysis, baseline SF-36 scores predicted subsequent response to pharmacological treatment. Results show an impaired HRQL in painful polyneuropathy and suggest that HRQL may predict response to analgesic treatment.

Topics: Adult; Aged; Aged, 80 and over; Analgesia; Analgesics; Cross-Over Studies; Cyclohexanols; Drug Resistance; Female; Health Status; Humans; Hypericum; Male; Middle Aged; Pain Measurement; Pain Threshold; Pain, Intractable; Placebos; Polyneuropathies; Quality of Life; Surveys and Questionnaires; Treatment Outcome; Valproic Acid; Venlafaxine Hydrochloride

Tricyclic antidepressants are the mainstay of treatment of painful polyneuropathy but cannot be used in a substantial number of patients. St. John's wort is a herbal antidepressant, which may act via mechanisms similar to the tricyclics. The aim of this study was to test if St. John's wort would relieve painful polyneuropathy. The study design was randomized, double-blind, placebo-controlled and cross-over. Fifty-four patients were assigned to one of the two treatment sequences. The daily dose of St. John's wort was three tablets each containing 900 microg totalhypericin. During the two treatment periods of 5 weeks duration, patients rated constant pain, lancinating pain paroxysms, touch-evoked pain and pain on pressure by use of 0--10 point numeric rating scales. Forty-seven patients -- 18 diabetics and 29 non-diabetics -- completed the study. There was a trend of lower total pain score (sum of the individual pain scores) on St. John's wort than on placebo (median 14 vs. 15, P=0.05). None of the individual pain ratings were significantly changed by St. John's wort as compared to placebo (P=0.09--0.33). Complete, good or moderate pain relief was experienced by nine patients with St. John's wort and two with placebo (P=0.07). In conclusion, St. John's wort has no significant effect on pain in polyneuropathy.

Topics: Adult; Aged; Aged, 80 and over; Antidepressive Agents; Double-Blind Method; Female; Humans; Hypericum; Male; Middle Aged; Neuralgia; Pain Measurement; Phytotherapy; Plants, Medicinal; Polyneuropathies; Treatment Failure