Omeprazole undergoes a chiral shift in vivo which converts the inactive (R)-enantiomer to the active (S)-enantiomer, doubling the concentration of the active form. This chiral shift is accomplished by the CYP2C19 isozyme of cytochrome P450, which is not found equally in all human populations. Those who do not metabolize the drug effectively are called "poor metabolizers". The proportion of the poor metabolizer phenotype varies widely between populations, from 2.0 to 2.5% in African Americans and white Americans to >20% in Asians. Several pharmacogenomics studies have suggested that PPI treatment should be tailored according to CYP2C19 metabolism status. Measurement in body fluids
Omeprazole may be quantified in plasma or serum to monitor therapy or to confirm a diagnosis of poisoning in hospitalized patients. Plasma omeprazole concentrations are usually in a range of 0.2–1.2 mg/L in persons receiving the drug therapeutically by the oral route and 1–6 mg/L in people with acute overdose. Enantiomeric chromatographic methods are available to distinguish esomeprazole from racemic omeprazole. History
Omeprazole was first made in 1979 by Swedish AB Hässle, part of Astra AB. It was the first of the proton pump inhibitors (PPI). Astra AB, now AstraZeneca, launched it as an ulcer medicine under the name Losec in Sweden. It was first sold in the United States in 1989 under the brand name Losec. In 1990, at the request of the U.S. Food and Drug Administration, the brand name Losec was changed to Prilosec to avoid confusion with the diuretic Lasix (furosemide).
Any child will experience nocturnal enuresis if more urine is produced than can be contained in the bladder or if the detrusor is hyperactive, provided that he or she is not awakened by the imminent bladder contraction. Primary nocturnal enuresis
Primary nocturnal enuresis is the most common form of bedwetting. Bedwetting becomes a disorder when it persists after the age at which bladder control usually occurs (4–7 years), and is either resulting in an average of at least two wet nights a week with no long periods of dryness or not able to sleep dry without being taken to the toilet by another person. New studies show that anti-psychotic drugs can have a side effect of causing enuresis.It has been shown that diet impacts enuresis in children. Constipation from a poor diet can result in impacted stool in the colon putting undue pressure on the bladder creating loss of bladder control (overflow incontinence).Some researchers, however, recommend a different starting age range. This guidance says that bedwetting can be considered a clinical problem if the child regularly wets the bed after turning 7 years old. Secondary nocturnal enuresis
Secondary enuresis occurs after a patient goes through an extended period of dryness at night (six months or more) and then reverts to night-time wetting. Secondary enuresis can be caused by emotional stress or a medical condition, such as a bladder infection. Psychological definition
Psychologists are usually allowed to diagnose and write a prescription for diapers if nocturnal enuresis causes the patient significant distress.