Find information about common, infrequent and rare side effects of Valium Oral. Abnormal Liver Function TestsSevere; Abnormally Low Blood PressureSevere. 1 Answer (question resolved) - Posted in: valium, high blood pressure, side effect - Answer: Hello it's a pontiac. Yes, you can take Diazepam. Diazepam reduces both arterial blood pressure and muscle sympathetic nerve activity in It is known that benzodiazepines have a hypotensive effect, but the.