Omeprazole is a drug used as short-term treatment for various ulcer diseases and conditions, esophagitis and heart burn. It comes in the forms of omeprazole/sodium bicarbonate, and omeprazole/magnesium, generally in delayed release tablets or capsules. Prilosec is one of the most propular name-brands of the medication. Side effects not requiring immediate medical attention. Some side effects of omeprazole may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. The effects of pantoprazole can last for up to seven days after you stop the medicine. Omeprazole: You may start to feel the effects of omeprazole one to two hours after taking the medication, but you may not feel full relief until you have been taking omeprazole for about four consecutive days. The effects of omeprazole can last for up to five. Learn about omeprazole (Prilosec), potential side effects, proper use and dosing, and popular alternatives. Read reviews from GoodRx users who have taken omeprazole (Prilosec) and find the latest news on the drug. Omeprazole (Oral Route) Print. Sections. Description and Brand Names; Before Using; Proper Use; Precautions; Side Effects; Products and services. 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. Check with your. Do not use omeprazole if you are also using medicines containing rilpivirine (Edurant®, Complera®). Using these medicines together may cause unwanted side effects. This medicine is sometimes given together with other medicines to treat ulcers. Be sure you understand about the risks and proper use of any other medicine your doctor gives you or. Omeprazole, approved by the FDA, is available as a prescription and over-the-counter (OTC) drug used as a treatment for frequent heartburn. Learn about side effects, drug interactions, dosages, warnings, and more. Omeprazole oral capsule doesn’t cause drowsiness. However, it can cause other side effects. More common side effects. The side effects from this drug are slightly different for children and adults. For GERD: “On omeprazole for 11 days, which 5 years ago & I had all side effects mentioned-anxiety, stomach pain, severe brain fog, etc. I had 3 trips to ER with heart pounding & racing numerous tests to try to diagnose. It took 6 months to feel 100%. Upped nutrition & made my own rehydration liquid (coconut water, fresh oranges & lemons,etc). About omeprazole Who can and cannot take omeprazole How and when to take omeprazole Side effects of omeprazole Pregnancy, breastfeeding and fertility while taking omeprazole Taking omeprazole with other medicines and herbal supplements.