What is the expected pharmacological action of propranolol?

Correct Answer: D

Rationale: Propranolol is a non-selective beta-blocker, which means it blocks the stimulation of both beta1 and beta2 adrenergic receptors. By blocking beta1 receptors in the heart, propranolol reduces heart rate and contractility, helping to lower blood pressure and decrease the heart's workload. Blocking beta2 receptors in the lungs may cause some constriction of the airways, so caution is required in patients with respiratory conditions.

Correct Answer: A

Rationale: The official name of a drug used in the United States Pharmacopeia-National Formulary (USP-NF) is the generic name. The generic name is the non-proprietary name of a drug, which is based on its chemical structure. It is important to distinguish the generic name from other types of names like the brand name (specific name given by the manufacturer) or proprietary name (registered trademark name owned by a pharmaceutical company). In the USP-NF, the generic name is used to refer to the drug in a standardized and universally recognized manner. This helps ensure clarity and consistency in the identification and communication of drug information.

Correct Answer: A

Rationale: One of the most common components added to local anesthetic solutions to reduce the systemic uptake of the anesthetic agent is a vasoconstrictor. Vasoconstrictors, such as epinephrine, work by causing constriction of blood vessels at the site of injection. This constriction reduces blood flow to the area, which in turn reduces the systemic absorption of the anesthetic agent. By limiting systemic absorption, vasoconstrictors can help to prolong the duration of local anesthesia and minimize potential side effects associated with high systemic levels of the anesthetic agent, such as cardiovascular effects.

Correct Answer: C

Rationale: Glyceryl trinitrate (nitroglycerin) is most effective when given sublingually for the treatment of angina pectoris. When administered sublingually, the medication is absorbed directly into the bloodstream through the oral mucosa, leading to rapid onset of action and providing quick relief of angina symptoms. This route bypasses first-pass metabolism in the liver, allowing the drug to exert its effects more rapidly. Orally administered glyceryl trinitrate is subject to extensive first-pass metabolism, and intravenous or intramuscular routes are generally reserved for acute situations where rapid onset of action is required. Subcutaneous administration is less commonly used compared to the sublingual route for the treatment of angina.

Correct Answer: B

Rationale: Drugs that act simultaneously on a mixed group of receptors with an agonist action on one set and with an antagonist action on the other are termed as mixed agonist-antagonists. These drugs can have a dual effect on different types of receptors within the same system. They can elicit both agonist-like responses at one receptor and antagonist-like responses at another receptor, leading to a mixed overall effect on the system. This unique property makes them different from pure agonists, pure antagonists, or partial agonists which typically have a unidirectional effect on receptors.