Quiz No 1 Pharmacology I

Explanation
Essential drugs are medications that are considered crucial for meeting priority healthcare needs and saving lives. These drugs are typically required to be readily available in emergency situations. They are selected based on their efficacy, safety, and cost-effectiveness, and are often listed in pharmacopeias, which are reference books containing information about drugs and their standards. These medications play a vital role in providing necessary treatment and improving health outcomes, particularly in resource-limited settings.

Explanation
The correct answer is "a drug needed for treatment or prevention of rare diseases." An orphan drug is a pharmaceutical product that is developed to treat or prevent medical conditions that affect a small number of people, typically fewer than 200,000 individuals in the United States. These diseases are often rare and have no existing or satisfactory treatment options available. The development of orphan drugs is incentivized by governments to encourage pharmaceutical companies to invest in research and development for these rare diseases.

Explanation
Oral drug administration is most likely to undergo first pass metabolism because it involves the ingestion of the drug through the mouth, where it is then absorbed into the gastrointestinal tract. From there, the drug is transported to the liver through the portal vein, where it undergoes metabolism before entering the systemic circulation. This first pass metabolism can significantly alter the drug's concentration and effectiveness, as the liver enzymes may metabolize and break down a portion of the drug before it reaches the bloodstream.

Explanation
Phenytoin sodium is a weakly acidic drug because it contains a weakly acidic functional group, the phenytoin molecule has a weakly acidic hydrogen atom that can be ionized in solution. The ionization of this hydrogen atom results in the formation of a negatively charged phenytoin ion, making it weakly acidic. Atropine sulphate, chloroquine phosphate, and ephedrine hydrochloride do not contain weakly acidic functional groups and therefore are not considered weakly acidic drugs.

Explanation
Enalapril is a prodrug because it is an inactive compound that is converted into its active form, enalaprilat, in the body. Enalaprilat is the active form that inhibits the enzyme responsible for the production of angiotensin II, a potent vasoconstrictor. By inhibiting this enzyme, enalaprilat helps to relax and widen the blood vessels, reducing blood pressure. The conversion of enalapril to enalaprilat occurs in the liver, making it a prodrug.