Drug X is a peptide hormone administered intravenously. Its

molecular properties include large size and hydrophilicity, which influence how

it distributes in the body.

Based on these characteristics, which statement BEST describes

the likely distribution of Drug X in the body?

Digoxin has a Vd of 7L/kg. What loading dose is required to achieve a plasma concentration of 10ng/mL?

Josh suffers from anxiety, which is treated effectively with alprazolam.  Josh develops arthritis and is given  a course of Dexamethasone for treatment. Dexamethasone is a known inducer of p-glycoprotein activity and Alprazolam is a known substrate for p-glycoprotein. 

Considering josh’s treatments for anxiety and arthritis, the most likely result of increased p-glycoprotein activity is? 

As part of the phase 1 clinical trial program for a new drug, a single dose of the drug is given to healthy volunteers and blood samples are taken at regular intervals to establish plasma drug concentrations (Cp).  The decrease in Cp over time is shown in the graph below. 

Based on this, which of the following predictions could be made about this new drug? It is:

Some medications can cause extremely rare adverse effects

that are unlikely to appear in small clinical trials but may have serious

consequences once the drug is used in a larger population.

Based on the typical goals, sample sizes, and durations

of clinical trials, at which stage is it MOST LIKELY that such rare adverse

effects would first be detected?

Drug Z is actively transported by p-glycoprotein, an efflux

transporter expressed in tissues such as the intestinal epithelium and the

blood–brain barrier, where it limits drug absorption and tissue penetration.

If p-glycoprotein activity is inhibited, which outcome is

MOST LIKELY for Drug Z?

In the Hedgehog signalling pathway,

Patched (PTCH) normally inhibits Smoothened (SMO) by preventing its

accumulation in the primary cilium. When Hedgehog ligand binds PTCH, SMO

translocates to the cilium leading to the activation of Gli transcription

factors. In a mouse model, researchers introduce the SmoM2 mutation, which

constitutively activates SMO, independent of PTCH inhibition.

Which of the following outcomes is

most likely in these mice?

A dermatologist sees a patient with

Gorlin Syndrome, noting multiple basal cell carcinomas and jaw keratocysts.

Genetic testing shows mutations in PTCH, part of the Hedgehog signalling

pathway.

Which explanation best accounts for

the development of basal cell carcinomas in these patients?

A dermatologist examines a patient with

several dysplastic nevi and explains that melanoma risk is higher in

individuals with many atypical moles because these lesions may already contain

genetic alterations in melanocytes.

Why do dysplastic nevi increase the

likelihood of melanoma developing?

Researchers evaluate the efficacy of a

tumour cell-specific therapeutic monoclonal antibody in co-culture experiments.

Tumour cells alone show minimal cell death when exposed to the antibody. When

peripheral blood mononuclear cells (PBMCs) are added, significant tumour cell

death occurs. Blocking Fc gamma receptors on the immune cells prevents killing,

while inhibition of the complement system has no measurable effect.

Which mechanism best explains the

observed tumour cell death?