The following sympathomimetic drug is a catecholamine:

Correct Answer: D

Rationale: The correct answer is D) Isoprenaline. Isoprenaline is a catecholamine because it has a catechol nucleus in its chemical structure, which is a defining characteristic of catecholamines. Catecholamines are a class of sympathomimetic drugs that act on adrenergic receptors. Isoprenaline specifically acts on both beta-1 and beta-2 adrenergic receptors. Option A) Ephedrine is a sympathomimetic amine but is not a catecholamine. It is a mixed-acting sympathomimetic drug that primarily acts by releasing norepinephrine. Option B) Phenylephrine is a sympathomimetic amine that acts as a selective alpha-1 adrenergic receptor agonist. It is not a catecholamine because it lacks the catechol nucleus in its structure. Option C) Phentolamine is an alpha-adrenergic antagonist, not a sympathomimetic drug. It is used to block the effects of catecholamines like norepinephrine and epinephrine. Educationally, understanding the classification of drugs based on their chemical structure is crucial for pharmacology students and healthcare professionals. Knowing the differences between various sympathomimetic drugs helps in understanding their mechanisms of action, indications, contraindications, and potential side effects, which are vital in clinical practice for making informed decisions regarding drug therapy.

Correct Answer: D

Rationale: In this question, the correct answer is D) Parathion - organophosphorus poisoning. Parathion is not a parasympathomimetic drug but rather an organophosphorus compound used as an insecticide. Therefore, it is not paired with an appropriate therapeutic use like the other options which are actual parasympathomimetics. A) Physostigmine is used in the form of eye drops in glaucoma to constrict the pupil and reduce intraocular pressure by increasing outflow of aqueous humor. B) Neostigmine is used for postoperative retention of urine by promoting bladder emptying through the stimulation of the parasympathetic nervous system. C) Edrophonium is used in the diagnosis of myasthenia gravis to differentiate it from cholinergic crisis by temporarily improving muscle strength in myasthenia gravis patients. Understanding the appropriate therapeutic uses of parasympathomimetic drugs is crucial in clinical practice, especially in fields like ophthalmology, anesthesia, and neurology. It is important for healthcare professionals to be able to differentiate between various drugs and their indications to ensure safe and effective patient care.

Correct Answer: C

Rationale: The correct answer is C) Adrenaline degradation. Monoamine oxidase enzyme (MAO) plays a crucial role in breaking down neurotransmitters such as adrenaline, dopamine, and serotonin. In the context of this question, MAO specifically targets adrenaline for degradation. This process is essential for regulating the levels of adrenaline in the body and ensuring proper physiological responses to stress and other stimuli. Option A) Adrenaline activation is incorrect because MAO does not activate adrenaline. Instead, it is involved in its breakdown. Option B) Adrenaline synthesis is incorrect because MAO is not involved in the synthesis of adrenaline. Adrenaline synthesis occurs through a different biochemical pathway. Option D) Acetylcholine degradation is incorrect because MAO primarily targets monoamine neurotransmitters like adrenaline, dopamine, and serotonin for degradation, not acetylcholine. Understanding the role of MAO in degrading adrenaline is crucial for healthcare professionals, especially those prescribing medications that interact with the monoaminergic system. By knowing how MAO functions, healthcare providers can better understand the effects of drugs that inhibit or interact with this enzyme, leading to safer and more effective patient care.

Correct Answer: C

Rationale: In this question about the therapeutic uses of adrenaline, the correct answer is C) To treat hypertension. Adrenaline, also known as epinephrine, is a hormone and neurotransmitter that plays a crucial role in the body's fight or flight response. While adrenaline is used for various therapeutic purposes, treating hypertension is not one of them. A) To prolong the action of local anesthetics: This is a correct therapeutic use of adrenaline. When combined with local anesthetics, adrenaline constricts blood vessels at the site of administration, reducing blood flow and thereby prolonging the anesthetic effect. B) To stop epistaxis: Adrenaline can be used to stop nosebleeds (epistaxis) by causing vasoconstriction in the blood vessels of the nose, which helps to reduce bleeding. D) To treat anaphylaxis: Adrenaline is a first-line treatment for anaphylaxis, a severe allergic reaction. It acts quickly to reverse the symptoms of anaphylaxis, such as airway constriction, low blood pressure, and hives, by dilating the airways and constricting blood vessels. Educationally, understanding the various therapeutic uses of adrenaline is important for healthcare professionals, especially those involved in emergency care, anesthesiology, and allergy management. Knowing when to administer adrenaline and its effects on the body can be life-saving in critical situations. It is crucial for students to grasp the nuances of pharmacology to make informed decisions in clinical practice.

Correct Answer: B

Rationale: Salbutamol is a medication classified as a beta-2 adrenergic agonist, primarily used to treat bronchospasm in conditions such as asthma and chronic obstructive pulmonary disease (COPD). The correct answer is B) Bronchial asthma because salbutamol works by relaxing the muscles in the airways, making it easier to breathe during an asthma attack or in conditions of bronchoconstriction. Option A) Angina pectoris is incorrect because salbutamol is not indicated for the treatment of angina. Angina is primarily treated with medications like nitroglycerin that help to dilate blood vessels to improve blood flow to the heart. Option C) Hypertension is incorrect because salbutamol can actually lead to an increase in blood pressure as a side effect due to its action on beta receptors. It is not used as a first-line treatment for hypertension. Option D) Cardiac arrhythmias is incorrect because while salbutamol can impact heart rate and rhythm, it is not a primary medication for managing cardiac arrhythmias. Medications like beta-blockers are more commonly used for this purpose. In an educational context, understanding the specific indications of medications like salbutamol is crucial for healthcare professionals to provide safe and effective care to patients. Knowing the correct uses of medications and their mechanisms of action helps in making informed decisions when managing patients with various medical conditions.