Stop using caffeine and ergotamine and call your doctor at once if you have a serious side effect such as: sudden numbness or weakness, especially on one side of the body; sudden headache, ; fast or slow heart rate; muscle pain in your arms or legs; numbness or tingling and a pale or blue-colored appearance in your fingers or toes; severe pain in your stomach or lower back; urinating less than usual or not at all; swelling or itching in any part of your body; trouble breathing