Medications bound to protein have the following effect:

Correct Answer: C

Rationale: When medications are bound to proteins in the bloodstream, they are inactive and unable to exert their therapeutic effects. Only the unbound (free) fraction of the drug is pharmacologically active. Therefore, the more a drug is bound to protein, the less available it is for its desired effect. Protein binding also affects the drug's distribution and metabolism, but it does not enhance availability or increase liver metabolism. Rapid distribution to receptor sites is influenced by other factors, such as blood flow and tissue permeability.

Correct Answer: A

Rationale: Hydrochlorothiazide (HydroDIURIL) is a diuretic that can cause electrolyte imbalances, particularly hypokalemia (low potassium levels). Digitalis (digoxin) is a medication commonly used to treat heart conditions, and its therapeutic effect is dependent on adequate potassium levels. If a patient taking hydrochlorothiazide becomes hypokalemic and then takes digitalis, it can lead to an increased risk of digitalis toxicity. This severe interaction highlights the importance of monitoring potassium levels and potential drug interactions when patients are taking hydrochlorothiazide. Potassium supplements would help counteract the potassium loss caused by hydrochlorothiazide and minimize the risk of interactions with digitalis.

Correct Answer: D

Rationale: Sildenafil (Viagra), a phosphodiesterase-5 inhibitor, treats erectile dysfunction (ED) by enhancing penile blood flow, a first-line therapy. Leuprolide suppresses testosterone for prostate cancer, worsening ED. Finasteride and tamsulosin, for BPH, don't target ED and may cause it. Sildenafil's vascular action offers rapid efficacy, making it the go-to choice.

Correct Answer: A

Rationale: Patients with peptic ulcers should stop taking NSAIDs (Nonsteroidal Anti-Inflammatory Drugs) because NSAIDs can worsen the condition and increase the risk of gastrointestinal bleeding and ulcer perforation. NSAIDs inhibit prostaglandin synthesis, which normally helps protect the stomach lining. Therefore, patients with peptic ulcers should avoid NSAIDs and consult their healthcare provider for alternative pain management options.

Correct Answer: A

Rationale: The unlabeled use for a medication refers to a use that is not approved by regulatory agencies but has shown effectiveness in clinical practice. In this case, the unlabeled use for a medication might be to treat PTSD (Post-Traumatic Stress Disorder). While the medication may not be specifically indicated for this condition, it may have shown benefits in managing the symptoms of PTSD based on clinical experience or research studies. It is important to note that using a medication for an unlabeled use should always be done under the supervision of a healthcare professional.