I've been taking Doxycycline 100mg once a day for the past three months for severe acne. I have experienced nausea and have been very close to vomitting when taking the pill on an empty stomach. Taking this pill before bedtime is a big mistake since the onset of stomach pain isn't immediate and usually occurs after 20 minutes or so. I now take the pill in the morning and a banana seems to do the trick for killing my stomach pain. In the past few days I've developed what feels like a stomach ulcer probably as a result of doubling my dosage for acne flare-ups. It causes acute stomach pain that comes in waves every 15 sec. and last for 5 sec. at a time. This pain is very severe. I have also experienced the tingling sensation (needles) in my hands when washing my hands but this happens only occassionly.