Prilosec Side Effects
Generic Name: omeprazole
Note: This document contains side effect information about omeprazole. Some of the dosage forms listed on this page may not apply to the brand name Prilosec.
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 (the active ingredient contained in Prilosec) 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 doctor immediately if any of the following side effects occur while taking omeprazole:
- Back, leg, or stomach pain
- bleeding or crusting sores on the lips
- bloody or cloudy urine
- continuing ulcers or sores in the mouth
- difficult, burning, or painful urination
- frequent urge to urinate
- general feeling of discomfort or illness
- joint pain
- loss of appetite
- muscle aches or cramps
- red or irritated eyes
- redness, tenderness, itching, burning, or peeling of the skin
- skin rash or itching
- sore throat
- sores, ulcers, or white spots on the lips, in the mouth, or on the genitals
- unusual bleeding or bruising
- unusual tiredness or weakness
Incidence Not Known
- fast, racing, or uneven heartbeat
- mood or mental changes
- muscle spasms (tetany) or twitching seizures
- nausea or vomiting
Get emergency help immediately if any of the following symptoms of overdose occur while taking omeprazole:
Symptoms of Overdose
- Blurred vision
- dryness of the mouth
- increased sweating
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. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- Body aches or pain
- chest pain
- diarrhea or loose stools
- difficulty with breathing
- ear congestion
- loss of voice
- muscle pain
- nasal congestion
- runny nose
- unusual drowsiness
For Healthcare Professionals
Applies to omeprazole: compounding powder, oral delayed release capsule, oral delayed release tablet, oral powder for reconstitution, oral powder for reconstitution delayed release, oral suspension
Lightheadedness occurred predominantly in severely ill or elderly patients.
Taste disturbance usually resolved when treatment was stopped.
Taste perversion most commonly occurred in patients given concomitant treatment with clarithromycin.
Very common (10% or more): Taste perversion (Up to 15%)
Common (1% to 10%): Headache, drowsiness, somnolence, dizziness
Uncommon (0.1% to 1%): Paresthesia, vertigo, taste disturbances
Rare (0.01% to 0.1%): Lightheadedness, hepatic encephalopathy
Postmarketing reports: Tremor[Ref]
Very common (10% or more): Diarrhea (Up to 14%)
Postmarketing reports: Pancreatitis (sometimes fatal), irritable colon, fecal discoloration, esophageal candidiasis, mucosal atrophy of the tongue, Clostridium difficile associated diarrhea, abdominal swelling[Ref]
Hemorrhagic necrotic gastritis has been reported in pediatric patients.
Diarrhea most commonly occurred in patients given concomitant treatment with clarithromycin and amoxicillin.
Benign gastric fundic gland polyps appeared to be reversible when omeprazole was discontinued.[Ref]
Common (1% to 10%): Upper respiratory infection, cough, rhinitis, pharyngitis/pharyngeal pain
Rare (0.01% to 0.1%): Bronchospasm
Very rare (less than 0.01%): Dyspnea
Postmarketing reports: Epistaxis[Ref]
Patients 1 to less than 2 years of age had the highest frequency of adverse reactions of the respiratory system, followed by patients 1 month to less than 1 year and patients 2 to 16 years of age.[Ref]
Otitis media occurred most frequently in patients 1 month to less than 1 year of age.
Fever most commonly occurred in patients 1 to less than 2 years of age.
Accidental injury most commonly occurred in patients 2 to 16 years of age.[Ref]
Common (1% to 10%): Asthenia, flu-syndrome, fever
Uncommon (0.1% to 1%): Malaise
Very rare (less than 0.01%): Elevated body temperature
Frequency not reported: Otitis media, accidental injury
Common (1% to 10%): Rash
Frequency not reported: Subacute cutaneous lupus erythematosus
Common (1% to 10%): Insomnia
Rare (0.01% to 0.1%): Agitation, confusion/reversible mental confusion, depression, aggression, hallucinations
Confusion, agitation, aggression, depression, and hallucinations occurred predominantly in severely ill or elderly patients.[Ref]
Common (1% to 10%): Back pain
Uncommon (0.1% to 1%): Fracture of the hip/wrist/spine
Rare (0.01% to 0.1%): Arthralgia, myalgia, muscular weakness, joint pain
Uncommon (0.1% to 1%): Increased liver enzymes (ALT, AST, GGT, alkaline phosphatase, bilirubin)
Rare (0.01% to 0.1%): Hepatitis with/without jaundice, hepatic failure/encephalopathy
Postmarketing reports: Liver disease, fatal hepatic failure, liver necrosis (some fatal), hepatocellular disease, cholestatic disease, mixed hepatitis, jaundice[Ref]
Uncommon (0.1% to 1%): Peripheral edema
Rare (0.01% to 0.1%): Hyponatremia
Frequency not reported: Hypocalcemia
Severe hypomagnesemia may result in hypocalcemia, and may be associated with hypokalemia.
Hypokalemia was reported in pediatric patients.[Ref]
Irreversible visual impairment has been reported in critically ill patients who generally received high doses of the IV formulation as a bolus; however, no causal relationship has been established.[Ref]
Rare (0.01% to 0.1%): Blurred vision
Frequency not reported: Irreversible visual impairment
Rare (0.01% to 0.1%): Interstitial nephritis
Very rare (less than 0.01%): Impaired renal function, nephrosis
Postmarketing reports: Elevated serum creatinine, glycosuria[Ref]
Very rare (less than 0.01%): Impotence
Rare (0.01% to 0.1%): Gynecomastia[Ref]
Postmarketing reports: Gastroduodenal carcinoids[Ref]
Gastroduodenal carcinoids have been reported in patients with Zollinger-Ellison syndrome on long-term therapy. This condition may be a manifestation of the underlying condition, which is known to be associated with tumors.[Ref]
1. Cerner Multum, Inc. "Australian Product Information." O 0
2. "Product Information. Zegerid (omeprazole)." Santarus Inc, San Diego, CA.
3. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
4. "Product Information. Prilosec (omeprazole)." Merck & Co, Inc, West Point, PA.
5. "Product Information. Omeprazole (omeprazole)." Mylan Pharmaceuticals Inc, Morgantown, WV.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Some side effects may not be reported. You may report them to the FDA.
More about Prilosec (omeprazole)
- During Pregnancy or Breastfeeding
- Dosage Information
- Patient Tips
- Drug Images
- Drug Interactions
- Compare Alternatives
- Support Group
- Pricing & Coupons
- En Español
- 35 Reviews
- Drug class: proton pump inhibitors
- Prilosec (Omeprazole Delayed-Release Capsules)
- Prilosec (Omeprazole Powder for Oral Suspension)
- Prilosec (Advanced Reading)