Find information about common, infrequent and rare side effects of Omeprazole Oral. Urine colour abnormal is found among people who take Omeprazole, especially for people who are male, 60+ old also take medication Ramipril, and have High blood pressure. This study is created by eHealthMe based on reports of 217,985 people who have side effects when taking Omeprazole from FDA, and is updated regularly. Uncommon omeprazole side effects (affect between 1 in 100 and 1 in 1000 people) Dizziness or spinning sensation. Sleepiness. Difficulty sleeping. Pins and needles sensations (paraesthesia). I also had/have a bit dark urine, orange/brown. Was scared, since I had gallstones and measured bilirubin, which was positive.It is often lighter when the urine is alcaline or when I take omeprazole (PPI) and darker when I eat beans. Along with its needed effects, omeprazole/sodium bicarbonate may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention. Although not all of these side effects may occur, if they do occur they may need medical attention. Omeprazole Liver Side Effects Esther Kinuthia RN BSN BA. Signs of acute liver failure include dark urine, clay colored stool, itching, yellowing of the skin and eyes, enlarged abdomen, abdominal pain, loss of appetite, nausea and vomiting. REFERENCES & RESOURCES. Druginformer Identified Side Effects: Arthralgia, Cold sweat, Dizziness, Nausea, Vomiting, Urine colour abnormal Posted By Anonymous in askapatient.com on April 16, 2010 @ 12:00 am “ Side Effects: omeprazole generic (same thing)Cures the acid problem when zantac couldnt. Signs of liver damage include itching, yellowing of the skin and eyes, upper right abdominal pain, clay colored stool and dark urine. Fractures MayoClinic.com states that long-term use of proton pump inhibitors such as Prilosec and Nexium may increase the risk of bone fractures in the body. For the Consumer. Applies to omeprazole: oral capsule delayed release, oral packet, oral powder for suspension, oral tablet delayed release. Along with its needed effects, omeprazole may cause some unwanted effects. Side Effects. Drug information provided by: IBM Micromedex. Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.