1.
A 27-year-old woman moves to Dominica from Toronto to go to medical school. Every day at noon, she goes to the beach and lies in the sun for half an hour in her bikini. Which of the following is the best description of the likely changes in her vitamin D profile?
Vitamin D
25(OH) D
1,25(OH)2 D
A
No change
Up
No change
B
Up
No change
down
C
Up
Up
No change
D
No change
No change
No change
E
Up
Up
Up
Correct Answer
C. C
Explanation
Moving from Toronto to Dominica, where there is more sunlight, will likely result in an increase in the woman's vitamin D profile. Sun exposure is the primary source of vitamin D synthesis in the body, and spending time in the sun in her bikini will allow her skin to produce more vitamin D. Additionally, the increased sunlight exposure in Dominica compared to Toronto will result in higher levels of 25(OH) D and 1,25(OH)2 D, which are the active forms of vitamin D in the body. Therefore, the best description of the likely changes in her vitamin D profile is an increase in all three forms of vitamin D (A, B, and C).
2.
Which of the following actions most likely mediates the therapeutic efficacy of calcitriol in rickets?
Correct Answer
D. Increased intestinal calcium absorption
Explanation
Calcitriol is the active form of vitamin D, and it plays a crucial role in maintaining calcium homeostasis in the body. Rickets is a condition characterized by impaired mineralization of growing bones, often due to vitamin D deficiency. One of the main therapeutic actions of calcitriol in rickets is to increase intestinal calcium absorption. By promoting the absorption of calcium from the intestines into the bloodstream, calcitriol helps to increase the availability of calcium for bone mineralization, thus improving the symptoms of rickets.
3.
Which of the following drugs appears to facilitate new bone formation if concomitant calcium supplementation is adequate?
Correct Answer
B. Fluoride
Explanation
Fluoride is the correct answer because it has been shown to facilitate new bone formation when calcium supplementation is adequate. Fluoride helps in the formation of hydroxyapatite, which is a key component of bone. It has been used in the treatment of osteoporosis and other bone disorders to increase bone density and strength. Calcium supplementation is important because fluoride works in conjunction with calcium to promote bone growth. Phenytoin, thyroxine, leuprolide, and prednisone do not have the same effect on bone formation as fluoride.
4.
A 52-year-old woman was admitted to the hospital because of tetanic muscle spasms
and paresthesias following a recent thyroidectomy. Which of the following drugs given IV
could rapidly reverse the patient’s symptoms?
Correct Answer
D. Calcium gluconate
Explanation
Calcium gluconate is the correct answer because it is a form of calcium that can be given intravenously to rapidly replenish calcium levels in the body. Tetanic muscle spasms and paresthesias are symptoms of hypocalcemia, which can occur after a thyroidectomy due to accidental removal or damage to the parathyroid glands. Calcium gluconate can quickly increase calcium levels and reverse these symptoms. Vitamin D, calcitonin, sodium phosphate, hydrocortisone, and alendronate are not indicated for the treatment of acute hypocalcemia.
5.
A 49-year-old woman complained to her physician of occasional, severe back pain.
Medical history of the patient was significant for mastectomy for breast cancer four years
ago, and for an episode of severe angioedema which occurred six month ago after a
prophylactic treatment with hepatitis A immune globulin. An x-ray showed diffuse
osteoporosis. Which of the following drugs would be most appropriate for this patient?
Correct Answer
C. Alendronate
Explanation
The patient's history of mastectomy for breast cancer and severe angioedema suggests that she may have received hormonal therapy or other treatments that can increase the risk of osteoporosis. Alendronate is a bisphosphonate medication that helps to prevent bone loss and is commonly prescribed for osteoporosis. It would be the most appropriate drug choice for this patient to help manage her severe back pain and improve her bone health.
6.
A 70-year-old woman suffering from osteoporosis and hypertension, has been treated
for the last three years with raloxifene and calcium carbonate (1.5 g daily) for
osteoporosis and with hydrochlorothiazide for hypertension. In spite of the therapy, a
recent bone mineral density showed a significant decrease in bone mass. Which of the
following would be an appropriate change in the treatment plan of this patient?
Correct Answer
F. To add alendronate to the present regimen
Explanation
Adding alendronate to the patient's current regimen would be an appropriate change in treatment plan. Alendronate is a medication that belongs to a class of drugs called bisphosphonates, which are commonly used to treat osteoporosis. It helps to increase bone mass by slowing down the breakdown of bone and reducing the risk of fractures. Since the patient has been experiencing a significant decrease in bone mass despite the current therapy, adding alendronate can help improve her bone density and reduce the risk of further bone loss.
7.
A 50-year-old man presented to the hospital because of increasingly severe bone
pain, which is accentuated at night, headache, fatigue and decreasing auditory acuity. Pasts history of the patient was significant for gastroesophageal reflux disease presently
treated with omeprazole. Physical examination revealed skull enlargement, a hobbing gait
and anterolateral bowing of the legs with warmth and periosteal tenderness. A X-ray exam
showed increased bone density, cortical thickening and bony enlargement. Laboratory
results showed alkaline phosphatase of 230 I.U./L (normal 20-90). Which of the following
drugs would be appropriate for this patient?
Correct Answer
A. Calcitonin
Explanation
The patient's presentation is consistent with Paget's disease of bone, which is characterized by bone pain, skull enlargement, gait abnormalities, and increased bone density on X-ray. The elevated alkaline phosphatase level further supports this diagnosis. Calcitonin is a medication that can help to reduce bone turnover and pain in patients with Paget's disease, making it the appropriate choice for this patient. Alendronate, calcium carbonate, sodium fluoride, raloxifene, and calcitriol are not indicated for the treatment of Paget's disease.
8.
A 4-year-old black boy was brought to the emergency room after he fell while playing
in the yard. Physical examination revealed only minor skin scratches but an x-ray exam
showed 2 rib fractures, a clearly demineralized bone and widening and cupping of
metaphyses with exaggerated normal concavity and irregular calcification. Pertinent
laboratory values were: calcium 8.3 mg/dL, phosphate 3.2 mg/dL, and a two fold increase
in alkaline phosphatase. Which of the following would be an appropriate treatment for
this boy?
Correct Answer
A. Cholecalciferol
Explanation
Cholecalciferol, also known as vitamin D3, would be an appropriate treatment for this boy. The presentation of rib fractures, demineralized bone, and metaphyseal abnormalities suggests a diagnosis of rickets, which is commonly caused by vitamin D deficiency. Cholecalciferol is a form of vitamin D that can help increase calcium and phosphate levels, improve bone mineralization, and promote proper bone growth. This treatment would address the underlying deficiency and support bone health in the boy.
9.
A 42-year-old man with 25-year history of type 1 diabetes presented for a control visit.
His laboratory values were: glucose 190 mg/dL, calcium 11.2 mg/dL, phosphate 5.3
mg/dL, creatinine 4.9 mg/dL. An x-ray exam revealed density changes in the bones that
were consistent with renal osteodystrophy. Which of the following drugs should be
included in the treatment plan for this patient?
Correct Answer
C. Paricalcitol
Explanation
Paricalcitol should be included in the treatment plan for this patient because the laboratory values and x-ray findings suggest that the patient has renal osteodystrophy, which is a common complication of chronic kidney disease. Paricalcitol is a synthetic vitamin D analog that is used to treat secondary hyperparathyroidism associated with chronic kidney disease. It helps to reduce elevated levels of parathyroid hormone, which can contribute to bone mineralization abnormalities. Therefore, paricalcitol would be an appropriate choice to address the bone density changes observed in this patient.
10.
A 46-year-old man presented to the hospital with complains of muscle weakness,
fatigue, constipation, nausea and polyuria. Past medical history was unremarkable.
Pertinent laboratory values on admission were: calcium of 14.5 mg/dL, phosphate 2.1
mg/dL and immunoreactive parathyroid hormone level of 142 pg/mL (normal 11-54).
Which of the following drugs was most likely included in the therapeutic management of
the patient?
Correct Answer
E. Calcitonin
Explanation
Calcitonin is the most likely drug included in the therapeutic management of the patient because the patient's laboratory values indicate hypercalcemia, with high levels of calcium and low levels of phosphate. Calcitonin is a hormone that helps regulate calcium levels in the body by inhibiting bone resorption and promoting calcium excretion in the kidneys. It is used as a treatment for hypercalcemia, which can cause symptoms such as muscle weakness, fatigue, constipation, nausea, and polyuria. Therefore, administering calcitonin would help lower the patient's calcium levels and alleviate their symptoms.
11.
A 55-year-old woman complained to her physician of a persistent back pain of 3 days
duration. A dual-energy x-ray absorptiometry showed diffuse osteoporosis of the spine
and hips. The physician ordered calcium and vit D supplementation and alendronate, 10
mg daily. Which of the following actions most likely mediated the therapeutic effect of
alendronate in this patient?
Correct Answer
D. Inhibition of osteoclast activity
Explanation
Alendronate is a bisphosphonate medication that is commonly used for the treatment of osteoporosis. It works by inhibiting the activity of osteoclasts, which are cells responsible for breaking down bone tissue. By inhibiting osteoclast activity, alendronate helps to decrease bone resorption and increase bone density, leading to the therapeutic effect in this patient. This medication does not stimulate osteoblast activity, intestinal calcium absorption, or renal calcium excretion. Additionally, it does not inhibit renal synthesis of calcitriol, which is the active form of vitamin D.
12.
A 63-year-old woman, suffering from osteoporosis, had been receiving alendronate,
and calcium and vit D supplementation for two years, but a recent dual-energy x-ray
absorptiometry showed a significant decrease in bone density. The patient history was
significant for a femur fracture 8 months ago and a rib fracture one months ago. The
physician decided to add teriparatide to the current therapy. Which of the following
actions most likely mediated the therapeutic effect of the drug in this patient?
Correct Answer
A. Stimulation of osteoblast activity
Explanation
Teriparatide is a recombinant form of parathyroid hormone (PTH) that stimulates osteoblast activity. Osteoblasts are responsible for bone formation, so by stimulating their activity, teriparatide helps to increase bone density. This is particularly beneficial for individuals with osteoporosis, as it helps to counteract the excessive bone resorption that occurs in this condition. Therefore, the addition of teriparatide to the patient's current therapy is likely to have a therapeutic effect by stimulating osteoblast activity and promoting bone formation.
13.
A 47-year-old man presented to his physician complaining of recurring skin lesions most prominent over the scalp, extensor surfaces of elbows and knees, buttock and penis.
The man also complained of increasing pain in his left hand and left hip. Physical
examination showed oval erythematous plaques covered with thick, silvery, shiny scales.
The distal interphalangeal joints of digits two and three of the left hand were swollen and
tender. The physician told the patient the diagnosis and ordered a topical drug treatment.
Which of the following drugs was most likely prescribed?
Correct Answer
C. Calcipotriene
Explanation
The patient's presentation is consistent with psoriasis, a chronic autoimmune disease characterized by erythematous plaques covered with silvery scales. The involvement of the scalp, extensor surfaces of elbows and knees, buttock, and penis, along with joint swelling and tenderness, suggests an active and severe form of psoriasis. Calcipotriene, a vitamin D analog, is commonly prescribed as a topical treatment for psoriasis due to its ability to inhibit keratinocyte proliferation and promote keratinocyte differentiation, leading to decreased inflammation and scaling. Therefore, calcipotriene is the most likely drug prescribed in this case.
14.
A 62-year-old man was admitted to the hospital because of increasing pain in the back
and left upper thigh over the past month. The patient also complained that recently he felt
drowsy and tired most of the time and urinated very frequently. Past history of the patient
was significant for radical prostatectomy for prostate cancer six months ago. Physical
examination showed a dehydrated man less alert than normal and slow in his responses.
Pertinent laboratory values on admission were: calcium 13.5 mg/L, alkaline phosphatase
204 U/L. An appropriate therapy was started which included an IV infusion of a drug.
Which of the following drugs was most likely infused IV?
Correct Answer
C. Pamidronate
Explanation
The patient's presentation is consistent with hypercalcemia, as indicated by the elevated calcium level and symptoms such as back pain, drowsiness, and frequent urination. Pamidronate is a bisphosphonate medication that is commonly used to treat hypercalcemia. It works by inhibiting osteoclast activity and reducing bone resorption, thereby lowering calcium levels in the blood. Therefore, the most likely drug infused IV in this case would be pamidronate.
15.
A 52-year-old homeless man with a 15 year history of alcoholism was brought to the
hospital by the police who found him laying on the street. Physical examination showed a
disheveled, confused and cachectic man with prominent veins on a very tense abdomen.
Pertinent laboratory values on admission were: calcium 5.5 mg/L, ALT 300 U/L (normal 8-
35), AST 255 U/L (normal 8-35). An x-ray disclosed diffuse demineralization of bones. An
appropriate therapy was ordered. Which of the following drugs was most likely included
in the therapeutic management of this patient?
Correct Answer
D. Calcitriol
Explanation
The patient's physical examination findings, laboratory values, and x-ray results suggest that he is suffering from alcoholic liver disease and hypocalcemia due to vitamin D deficiency. Calcitriol, the active form of vitamin D, is the most appropriate therapy for this patient as it helps in increasing calcium absorption from the gut and promoting bone mineralization. Teriparatide is a recombinant form of parathyroid hormone and is used for osteoporosis, not for hypocalcemia. Cholecalciferol is a form of vitamin D that is used for vitamin D deficiency, but the patient's condition requires the active form of vitamin D. Sodium fluoride is used for the treatment of osteoporosis, not for hypocalcemia. Calcipotriene is a synthetic form of vitamin D that is used for the treatment of psoriasis, not for hypocalcemia.
16.
A 56-year-old woman complained to her physician of frequent heartburn and pain in
the substernal region. The woman, recently diagnosed with postmenopausal
osteoporosis, started an appropriate therapy two weeks previously. Which of the
following drugs most likely caused the patient’s symptoms?
Correct Answer
E. Alendronate
Explanation
Alendronate is a bisphosphonate medication commonly used to treat osteoporosis. One of the common side effects of alendronate is gastrointestinal irritation, which can manifest as heartburn and substernal pain. Therefore, it is likely that alendronate caused the patient's symptoms of frequent heartburn and pain in the substernal region.