Explanation
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.

Explanation
Categorical data includes ordinal (ordered categories) and nominal (unordered categories). NYHA I-IV and grade of breast cancer are considered ordinal data because the categories for the answer choice are in order, you can have NYHA class I, II, III, or IV. Grade of breast cancers are also in order, grade 1, 2, or 3. Sex, Improvemnet Yes/No, Alive or Dead is considered nominal, unordered data because the answer choices are female or male, and do not have a set order.

Seizure threshold can be lowered by bupropion, chlorpromazine, clozapine, maprotiline, olanzapine, thioridazine, thiothixene, and tramadol.

Explanation
A, B, C. Hepatotoxicity, including hepatic failure, has been fatal and may more commonly occur in the first 6 months of treatment. Valproic acid and its analogs are contraindicated in patients with known urea cycle disorders. Patients with urea cycle disorders have a genetic enzyme defect leading to an impaired ability to produce urea. Hyperammonemic encephalopathy has been reported following initiation of valproate therapy.
Because of, inhibition of the secondary phase of platelet aggregation, and abnormal coagulation parameters complete blood counts and coagulation tests are recommended before initiating valproic acid therapy and at periodic intervals.

Explanation
Moderate-Intensity Statin Therapy: Atorvastatin 10 (20) mg, Rosuvastatin (5) 10 mg, Simvastatin 20-40 mg, Pravastatin 40 (80) mg, Lovastatin 40 mg, Fluvastatin XL 80 mg, Fluvastatin 40 mg bid, Pitavastatin 2-4 mg