Pharmacology - An Illustrated Review

Questions & Answers

Review Questions

1. Which of the following is used to reduce the size of the thyroid prior to surgery?

A.   Propylthiouracil

B.   Levothyroxine

C.   Iodine

D.   Liotrix

E.   Radioactive iodine (131I)

2. A patient is brought to the emergency room with tachycardia, muscle weakness, nervousness, fever, vomiting, extreme sweating, and delirium. Laboratory tests show an elevated serum free tetraiodothyronine, or thyroxine (T4), and a decreased thyroid-stimulating hormone (TSH) level. To rapidly prevent the synthesis of thyroid hormones, methimazole is given. What is the prescribed action of this drug?

A.   To inhibit tyrosine hydroxylase, thereby decreasing norepinephrine formation

B.   To inhibit thyroid peroxidase, thereby decreasing the formation of thyroxine (T4) and triiodothyronine (T3)

C.   To inhibit Ca2+ uptake by the endoplasmic reticulum

D.   To increase the secretion of thyroxine

E.   To inhibit growth of parenchymal cells

3. One hour later, the patient in question 2 is given stable iodine as a saturated solution of potassium iodide. What is the purpose of giving high iodide concentrations?

A.   To inhibit thyroid hormone release

B.   To replenish depleted iodine stores

C.   To overcome the thyroid effects of methimazole

D.   To prevent cardiac side effects of methimazole

E.   To replace salts lost by sweating

4. Iodides cannot be used long term to control thyrotoxicosis (hyperthyroidism) because the inhibitory actions of iodide decrease within several weeks. Which of the following treatments can be used to produce a long-term decrease in thyroid hormone levels?

A.   Levothyroxine

B.   Flurouracil

C.   Parathyroid hormone

D.   Calcitriol

E.   Radioactive iodine (131I)

5. Which of the following stimulates conversion of vitamin D precursor to calcitriol at the kidneys?

A.   Levothyroxine

B.   Methimazole

C.   Perchlorate

D.   Parathyroid hormone

E.   Calcitonin

6. A 62-year-old postmenopausal Caucasian woman experienced menopause in her early 50s and has been under hormone replacement therapy with a conjugated estrogen preparation since that time. She is not on any other medications. She has become concerned about the dangers associated with long-term hormone replacement therapy. If the goal of therapy is primarily for prevention of osteoporosis, which of the following therapies might be an appropriate substitute?

A.   Estrogen only

B.   Progestin only

C.   A second-generation sulfonylurea

D.   Ergonovine

E.   A bisphosphonate

7. A 25-year-old man reports becoming exhausted easily and having intestinal pains. The patient also reports being irritable, vomiting for many days, and having a sore throat. Examination shows purple spots on his rib cage and legs. His skin appears tanned even in un-exposed areas. The patient has also lost weight. The morning cortisol level after intravenous cosyntropin is unchanged. What would be the primary drug therapy for this patient?

A.   Corticorelin

B.   Aminoglutethimide

C.   Levothyroxine

D.   Hydrocortisone

E.   Mifepristone

8. Although the patient in question 7 reports feeling much better after primary drug therapy, he still feels dizzy when standing. Serum Na+ is low, and urinary Na+ is increased. This patient may benefit from the addition of which of the following drugs?

A.   Cortisol (p.o.)

B.   Spironolactone

C.   Dexamethasone

D.   Fludrocortisone

E.   Mifepristone

9. A long-acting synthetic antiinflammatory steroid is

A.   fludrocortisone.

B.   dexamethasone.

C.   prednisone.

D.   cortisol.

E.   aldosterone.

10. Which one of the following is an adverse effect of high-dose estrogen therapy?

A.   Acne

B.   Lymphopenia

C.   Weight loss

D.   Thromboembolism

11. Which of the following is most effective in stimulating protein synthesis in skeletal muscle?

A.   Cortisol

B.   Flutamide

C.   Estradiol

D.   Testosterone

E.   Progesterone

12. An antiandrogen that blocks the prostatic 5α-reductase that catalyzes the conversion of testosterone to dihydrotestosterone and thereby may lead to a reduction in the size of the prostate in men with benign prostatic hypertrophy is

A.   prednisone.

B.   finasteride.

C.   mifepristone.

D.   hydrocortisone.

E.   spironolactone.

13. A known diabetic patient is brought to the emergency room in a deep coma. There is an obvious need for immediate treatment, but the instrument used to determine plasma glucose concentration is not working, and the laboratory cannot supply the result in less than 1 hour. The best emergency procedure is the prompt administration of which of the following?

A.   Crystalline (regular) insulin

B.   Neutral Protamine Hagedorn (NPH) insulin

C.   A second-generation sulfonylurea

D.   Oral glucose

E.   Intravenous glucose

14. A 58-year-old man was found on a routine physical to have a fasting blood glucose level of 200 mg/dL and a positive urine test for glucose. There are no other remarkable signs. He is 70 inches (177 cm) tall and weighs 210 lb (95 kg). What would be the first step in the management of this patient's diabetes?

A.   Prescribe a morning dose of 10 units of Neutral Protamine Hagedorn (NPH) insulin with additional 5 unit doses of regular insulin before each meal.

B.   Place him on a 1200 kcal diet, with a modest exercise program.

C.   Prescribe 500 mg of tolbutamide twice daily.

D.   Prescribe 50 mg of a second-generation sulfonylurea once a day.

E.   Advise him to avoid excess sweets and stress.

15. Which treatment would be administered to the patient in question 14 second if the first treatment is ineffective?

A.   Crystalline (regular) insulin

B.   Neutral Protamine Hagedorn (NPH) insulin

C.   Metformin

D.   Methylphenidate

E.   Intravenous (IV) glucose

Answers and Explanations

1. C Iodine is used before thyroidectomy. It is not used for long-term treatment of hyperthyroidism because its effects are temporary (p. 145).

A, E Propylthiouracil and radioactive iodine (131I) are used to treat hyperthyroidism.

B, D Levothyroxine and liotrix are used to treat hypothyroidism.

2. B The symptoms indicate hyperthyroidism, which is confirmed by the laboratory results. Thus, a drug is needed that will decrease thyroid hormone levels. Methimazole inhibits thyroid peroxidase, decreasing the formation of thyroxine (T4) and triiodothyronine (T3), and thus is an effective treatment for hyperthyroidism (p. 144).

A, C–E None of the other choices describe the mechanism of action of methimazole.

3. A Iodine (supraphysiological dose) inhibits thyroid hormone release (p. 145).

B—E None of the other choices describe the rationale for giving iodine.

4. E Radioactive iodine accumulates in the thyroid gland and destroys parenchymal cells thereby producing a long-term decrease in thyroid hormone levels (p. 145).

A Levothyroxine is the synthetic sodium salt of T4, or thyroxine and is the drug of choice for replacement therapy of thyroid hormone in hypothyroidism.

B Flurouracil is a pyrimidine analogue used in treating cancer.

C Parathyroid hormone is a hormone released from the parathyroid gland and is involved in calcium homeostasis.

E Calcitriol (1,25 [OH]2D3) is the active form of vitamin D.

5. D Parathyroid hormone stimulates the formation of active vitamin D3, calcitriol (1,25-[OH]2D3), by the kidneys (p. 147).

A Levothyroxine is a synthetic sodium salt of thyroxine and is used to treat hypothyroidism, autoimmune thyroiditis, and thyroid cancer.

B Methimazole inhibits the iodination of tyrosyl residues in thyroglobulin and is used in the treatment of hyperthyroidism.

E Calcitonin acts on bone and kidneys to decrease calcium levels in the blood.

6. E Biphosphonates are analogues of pyrophosphate that accumulate in bone and prevent bone resorption in osteoporosis by inhibiting osteoclast activity (p. 149).

A Because the goal is to stop taking estrogens, choice A is not valid. B Progestin does not have beneficial effects on bone.

C Second-generation sulfonylureas are used to treat type 2 (non-insulin-dependent) diabetes mellitus.

D Ergonovine is an ergot alkaloid used to prevent and treat postpartum hemorrhage and to hasten involution of the uterus.

7. D These are signs and symptoms of primary adrenal insufficiency (Addison disease). The lack of cortisol response to intravenous administration of cosyntropin, an adrenocorticotropic hormone (ACTH) agonist, is confirmatory. Treatment is to replace the lack of cortisol with hydrocortisone, a synthetic glucocorticoid, given orally once or twice per day (p. 154).

A Corticorelin, or ovine corticotropin-releasing hormone, is used to differentiate pituitary ACTH-dependent Cushing disease from ectopic ACTH-secreting tumors (Cushing syndrome).

B Aminoglutethimide suppresses the adrenal cortex by inhibiting enzymatic conversion of cholesterol to pregnenolone and inhibiting synthesis of adrenal steroids.

C Levothyroxine is used for replacement therapy in hypothyroidism.

E Mifepristone is a competitive antagonist of progesterone.

8. D The symptoms indicate the patient also has a deficiency of the mineralocorticoid aldosterone. Fludrocortisone is a synthetic mineralocorticoid used to treat aldosterone deficiency (p. 156).

A Cortisol is the natural glucocorticoid hormone and is not effective orally.

B Spironolactone is an aldosterone antagonist that would worsen the patients symptoms.

C Dexamethasone is a synthetic glucocorticoid that would be un-helpful in treating the mineralocorticoid aspect of the disease.

E Mifepristone is a competitive antagonist of progesterone.

9. B Dexamethasone is a synthetic steroid with a long duration of action (p. 154).

A Fludrocortisone is a synthetic aldosterone analogue used in salt-losing forms of adrenal insufficiency.

C, D Prednisone is an intermediate-acting synthetic steroid, and cortisol is the natural short-acting hydrocortisone.

E Aldosterone is the major mineralocorticoid produced by the adrenal glands. It has a very short half-life and is not used therapeutically.

10. D Of the side effects listed, thromboembolism is the one most likely to be seen with estrogen therapy (p. 160).

A and B Acne is often seen in anabolic steroid usage (androgen effects) or progesterone therapy.

B Lymphopenia is not seen with estrogen therapy.

C Estrogen therapy may cause weight gain, not loss.

11. D Testosterone is the natural anabolic androgen hormone that stimulates an increase in skeletal muscle (p. 166).

A Cortisol is a natural glucocorticoid whose actions on protein metabolism are mainly catabolic (i.e., increased protein breakdown and decreased protein synthesis).

B Flutamide is a competitive antagonist of testosterone and would therefore block its effects on skeletal muscle.

C, E Estradiol and progesterone are female hormones that do not have anabolic effects on skeletal muscle.

12. B Finasteride blocks the conversion of testosterone to dihydrotestosterone by inhibiting the enzyme 5α-reductase and thus has antiandrogenic activity (p. 167).

A, C—E Prednisone and hydrocortisone are glucocorticoids, spironolactone is an aldosterone receptor antagonist, and mifepristone is a progesterone antagonist.

13. E This is a hypoglycemic emergency, and the patient is unable to take oral glucose (D). A bolus of dextrose (glucose) should be given, followed by continuous infusion of a dextrose-containing solution.

A–C Insulin and the sulfonylureas are antihyperglycemics and would worsen the patient's condition.

14. B The symptoms and complications of type 2 diabetes are worsened by being overweight and leading a sedentary lifestyle. Thus, the initial therapy is to institute lifestyle changes that may be sufficient to decrease blood glucose.

A, C, D are not the initial choices for type II diabetes.

E is an insufficient approach.

15. C Metformin is a biguanide that decreases hepatic gluconeogenesis and absorption of glucose from the gastrointestinal tract while increasing insulin sensitivity of skeletal muscle and adipose tissue. Because metformin does not increase the release of pancreatic insulin, the risk of hypoglycemia is less than that found for the sulfonylurea agents (e.g., tolbutamide), which would be a likely third choice for the patient if metformin is ineffective (p. 174).

A, B Insulin is not the usual choice for type 2 diabetes mellitus.

D Methylphenidate is a CNS stimulant used to treat ADHD and is not effective in Type II diabetes.

E IV glucose would worsen the condition.