A pregnant patient is in premature labor. Which class of drug will you question?

Choice A Reason:

Beta2 activation results in bronchodilation. This is a well-known effect where the activation of beta2 adrenergic receptors in the smooth muscle of the airways leads to relaxation and widening of the airways, making it easier to breathe. This effect is commonly utilized in the treatment of asthma and other respiratory conditions.

Choice B Reason:

Beta2 activation also results in glycogenolysis. This process involves the breakdown of glycogen into glucose, which increases blood sugar levels. This effect is part of the body’s response to stress, providing additional energy for the “fight or flight” response.

Choice C Reason:

Beta2 activation results in vasodilation of skeletal muscles. This means that the blood vessels supplying the skeletal muscles widen, increasing blood flow to these muscles. This effect helps to deliver more oxygen and nutrients to the muscles during periods of increased activity.

Choice D Reason:

This is the correct answer. Beta2 activation does not result in the contraction of uterine muscle; rather, it causes relaxation of the uterine smooth muscle. This effect is beneficial in preventing premature labor by reducing uterine contractions. Therefore, the statement that beta2 activation results in contraction of uterine muscle is incorrect and indicates a need for further teaching.

Choice A Reason:

Psychosocial factors, such as stress, beliefs, and expectations, can influence drug response to some extent. However, they are not the primary reason for the most common variations in drug response. These factors might affect how a patient perceives the effectiveness of a drug, but they do not significantly alter the pharmacokinetics or pharmacodynamics of the drug itself.

Choice B Reason:

Drug receptor sites can vary between individuals, affecting how well a drug binds and exerts its effect. While this can contribute to differences in drug response, it is not the most common cause. Variations in receptor sites are often due to genetic differences, which can influence the efficacy and potency of a drug.

Choice C Reason:

This is the correct answer. The metabolism of drugs is the most common cause of variation in drug response among individuals. Differences in metabolic rates can be attributed to genetic factors, age, liver function, and the presence of other medications. These factors affect how quickly a drug is broken down and eliminated from the body, leading to variations in drug levels and responses.

Choice D Reason:

Hypersensitivity potential refers to the likelihood of an individual having an allergic reaction to a drug. While this can cause significant differences in drug response, it is not the most common reason for variations. Hypersensitivity reactions are relatively rare compared to metabolic differences.