Persistent parotid pain due to guanacline.

Details are given of 17 patients who developed parotid pain during treatment with guanacline and which persisted after cessation of guanacline for upto five and a half years. These patients are compared with 17 patients who received similar treatment with guanacline and who did not develop parotid pain. There was no significant difference between patients who experienced parotid pain and those who did not with respect to sex, age, clinical diagnosis, blood urea, previous hypotensive therapy or other drugs given concurrently with guanacline. There was a slightly greater association of parotid pain with other side effects and with a larger daily dose of guanacline. It is suggested that persistent parotid pain after guanacline therapy is due to prolonged or permanent selective sympathetic nerve damage in the region of the cervical sympathetic nerve supply to the salivary glands.