NAPLEX Exam Dumps : North American Pharmacist Licensure Examination

Omeprazole is CYP2C19 inhibitor which can prolong the elimination of warfarin, particularly R-warfarin. R- warfarin is partially metabolized by CYP2C19. The combined use of omeprazole and warfarin has been associated with reports of increased INR and prothrombin time (PT).

Common GI side effects of Valproic Acid and Divalproex Sodium are Weight gain, Nausea, Vomiting, Diarrhea, abdominal pain, dyspepsia. Divalproex sodium or valproic acid affects reproductive endocrine function in women. Menstrual irregularities defined as amenorrhea, oligomenorrhea, and prolonged cycles were common. Gynecomastia is not a side effect of Divalproex Sodium. For list of drugs that causes gynecomastia refer the reference. Gingival hyperplasia is a well-known side effect of phenytoin.

It is not necessary that all the drugs get completely absorbed after oral administration. Most of them are incompletely absorbed. The extent of absorption varies from 5 to less than 100 % with oral ingestion of drugs.

Drugs which are too hydrophilic like atenolol are incompletely absorbed because the drug cannot cross the

lipid membrane due to high hydrophilic nature of the drug. Similarly, drugs which are too lipophilic like acyclovir are not soluble enough to cross the water layer adjacent to the cell. P-glycoprotein is an efflux transporter which is present in the enterocytes and it inhibits absorption of drug. It is also known as export transporter or reverse transporter. It has many drugs as its substrate. Grape juice in fact inhibits P-glycoprotein in the intestine thereby decreasing the efflux of drug from the cells by P-glycoprotein. Thus ingestion of grape juice may lead to significantly increased absorption of the drug.