Rare side effects, seen in more than 1 in 10,000 patients but less than 1 out of 1,000, include low blood sugar levels, depression, feeling restless (agitation), pins and needles, blurred vision, stroke (cerebrovascular disturbance), swelling of the voice box, abdominal pain, diarrhoea, vomiting, jaundice, increased liver enzymes in the blood, rash, itching or reddening of the skin, impotence, painful, persistent erection of the penis and low body temperature (especially in the elderly).