I too was prescribed zantac (
Ranitidine) and I began taking them last week
for nausea and was having light chest pain.( Less serious Zantac side effects may include:headache (may be severe);drowsiness, dizziness;sleep problems (insomnia);decreased sex drive, impotence, or difficulty having an orgasm; or swollen or tender breasts (in men);nausea, vomiting, stomach pain; or diarrhea or constipation so yes those are some of the side effects your having.