Analgesic effect of peridural labetalol in the treatment of cancer pain.

Labetalol is an alpha- and beta-blocking agent commonly used in anti-hypertensive therapy. Because of its beta-blocking and local anesthetic effect, labetalol via peridural catheter was supposed to reduce pain in patients suffering from gynecologic cancers. Thirty patients with terminal carcinomas (breast, uterus, ovary), whose pain was caused either by bone metastases or by primary invasion cancer, were treated. Peridural catheters were inserted and fixed at various levels, thoracic or lumbar, and 50 mg labetalol was injected every 4 h at the beginning and every 12-24 h on the following 2-3 days. The analgesia started immediately during the injection. No sensitive damage or neurovegetative block appeared. In 40% of the patients the catheter was removed after a 3-day treatment because of the definitive suppression of pain. Other analgesics were not required during the treatment; no tolerance to the drug was developed. The peridural catheter remained in situ for an average period of 4-30 days. Afterward it was possible to treat more cases as outpatients depending on their general conditions and with the help of their family doctors. After a few days of therapy, almost all the patients reported a burning pain at the site of the injection; this problem was easily resolved by prior injection of a 4-mg dose of betamethasone.