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.
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:
Incidence not known
Get emergency help immediately if any of the following symptoms of overdose occur while taking omeprazole:
Symptoms of overdose
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:
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
The most commonly reported side effects included headache, abdominal pain, nausea, and diarrhea.
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.
Very common (10% or more): Fever (up to 33%), otitis media (up to 22%)
Common (1% to 10%): Accidental injury, asthenia
Uncommon (0.1% to 1%): Malaise
Very rare (less than 0.01%): Elevated body temperature
Postmarketing reports: Pain, fatigue, tinnitus
Very common (10% or more): Respiratory system reactions (up to 75%)
Common (1% to 10%): Cough, pharyngitis/pharyngeal pain, rhinitis, upper respiratory infection
Rare (0.01% to 0.1%): Bronchospasm
Very rare (less than 0.01%): Dyspnea
Postmarketing reports: Epistaxis
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.
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.
Hepatic encephalopathy occurred in patients with preexisting liver disease.
Very common (10% or more): Taste perversion (up to 15%)
Common (1% to 10%): Dizziness, drowsiness, headache, somnolence
Uncommon (0.1% to 1%): Paresthesia, taste disturbances, vertigo
Rare (0.01% to 0.1%): Hepatic encephalopathy, lightheadedness
Postmarketing reports: Tremor
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 (the active ingredient contained in Prilosec) was discontinued.
Very common (10% or more): Diarrhea (Up to 14%)
Common (1% to 10%): Abdominal pain, acid regurgitation, benign fundic gland polyps, constipation, flatulence, nausea, tongue discoloration, vomiting
Rare (0.01% to 0.1%): Dry mouth, gastrointestinal candidiasis, microscopic colitis, stomatitis
Very rare (less than 0.01%): Dyspepsia, hemorrhagic necrotic gastritis
Postmarketing reports: Abdominal swelling, Clostridium difficile associated diarrhea, esophageal candidiasis, fecal discoloration, fundic gland polyps, irritable colon, mucosal atrophy of the tongue, pancreatitis (sometimes fatal)
Common (1% to 10%): Rash
Uncommon (0.1% to 1%): Alopecia, dermatitis, erythema multiforme, increased sweating, pruritus, photosensitivity, skin eruptions, urticaria
Rare (0.01% to 0.1%): Allergic vasculitis, Stevens-Johnson syndrome, toxic epidermal necrolysis (some fatal)
Frequency not reported: Subacute cutaneous lupus erythematosus
Postmarketing reports: Cutaneous lupus erythematosus, dry skin, hyperhidrosis, petechia, skin inflammation, severe generalized skin reactions, systemic lupus erythematosus
Common (1% to 10%): Back pain
Uncommon (0.1% to 1%): Fracture of the hip/wrist/spine
Rare (0.01% to 0.1%): Arthralgia, joint pain, muscular weakness, myalgia
Postmarketing reports: Bone fracture, leg pain, muscle cramps
Common (1% to 10%): Insomnia
Rare (0.01% to 0.1%): Aggression, agitation, confusion/reversible mental confusion, depression, hallucinations
Postmarketing reports: Anxiety, apathy, dream abnormalities, nervousness, psychiatric and sleep disturbances
Confusion, agitation, aggression, depression, and hallucinations occurred predominantly in severely ill or elderly patients.
Common (1% to 10%): Flu syndrome
Uncommon (0.1% to 1%): Increased liver enzymes (ALT, alkaline phosphatase, AST, bilirubin, gamma glutamyl transferase)
Rare (0.01% to 0.1%): Hepatic failure, hepatitis with/without jaundice
Postmarketing reports: Cholestatic disease, fatal hepatic failure, hepatocellular disease, jaundice, liver disease, liver necrosis (some fatal), mixed hepatitis
Uncommon (0.1% to 1%): Peripheral edema
Postmarketing reports: Bradycardia, chest pain/angina, elevated blood pressure/hypertension, palpitations, tachycardia
Peripheral edema usually resolved when treatment was stopped.
Rare (0.01% to 0.1%): Agranulocytosis, hypochromic/microcytic anemia, leukopenia, pancytopenia, thrombocytopenia
Postmarketing reports: Anemia, fatal agranulocytosis, hemolytic anemia, leukocytosis, neutropenia, purpura
Rare (0.01% to 0.1%): Anaphylactic reaction/shock, angioedema, hypersensitivity reactions
Postmarketing reports: Anaphylaxis
Severe hypomagnesemia may result in hypocalcemia, and this condition may be associated with hypokalemia.
Hypokalemia was reported in pediatric patients.
Rare (0.01% to 0.1%): Hyponatremia
Very rare (less than 0.01%): Hypocalcemia, hypokalemia, hypomagnesemia with/without hypocalcemia and/or hypokalemia, weight increase
Postmarketing reports: Anorexia, cyanocobalamin (vitamin B12) deficiency, hypoglycemia
Rare (0.01% to 0.1%): Interstitial nephritis
Very rare (less than 0.01%): Impaired renal function, nephrosis
Postmarketing reports: Elevated serum creatinine, glycosuria
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.
Rare (0.01% to 0.1%): Blurred vision
Frequency not reported: Irreversible visual impairment
Postmarketing reports: Anterior ischemic optic neuropathy, double vision, dry eye syndrome, ocular irritation, optic atrophy, optic neuritis
Rare (0.01% to 0.1%): Gynecomastia
Very rare (less than 0.01%): Impotence
Postmarketing reports: Hematuria, microscopic pyuria, proteinuria, testicular pain, urinary frequency, urinary tract infection
A causal relationship between this drug and impotence has not been established.
Postmarketing reports: Gastroduodenal carcinoids
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.
Medically reviewed by BestRx Medical Team Last updated on 1/1/2020.
Source: Drugs.com Prilosec