Pharmacology Practice Quiz 5

Answer: C – Infection.

Explanation: A foreign body in a blood vessel increases the risk of infection. Catheters that come outside the body have an even higher risk of infection. Most infections are caused by skin bacteria. Other infective organisms include yeasts and fungi. Options 1 and 4 are complications of a CVAD but are not the primary problem. Once placed, these lines do not cause pain and discomfort.

Answer: D – Heparin in instilled into the lumen of the catheter to decrease the risk of clotting.

Explanation: A solution containing heparin is used to reduce catheter clotting and maintain patency. The concentration of heparin used depends on the patient’s age, comorbidities, and the frequency of catheter access/flushing. Although patients have few complications, the device is not risk free. Patients may develop infection, catheter clots, vascular obstruction, pneumothorax, hemothorax, or mechanical problems (catheter breakage). Strict adherence to protocol enhances the longevity of central access devices. They routinely last weeks to months and sometimes years. The patient will be taught how to perform dressing changes at home.

Answer: A – Cross-link DNA strands with covalent bonds between alkyl groups on the drug and guanine bases on DNA.

Explanation: Alkylating agents are highly reactive chemicals that introduce alkyl radicals into biologically active molecules and thereby prevent their proper functioning, replication, and transcription. Alkylating agents have numerous side effects including alopecia, nausea, vomiting, and myelosuppression. Nitrogen mustards have a broad spectrum of activity against chronic lymphocytic leukemia, non-Hodgkin’s lymphoma, and breast and ovarian cancer, but they are effective chemotherapeutic agents because of DNA cross-linkage. Alkylating agents are non cell cycle-specific agents.

Answer: C – Estrogen antagonists to treat breast cancer.

Explanation: Estrogen antagonists are used to treat estrogen hormone-dependent cancer, such as breast carcinoma. A well-known estrogen antagonist used in breast cancer therapy is tamoxifen (Nolvadex). This drug, in combination with surgery and other chemotherapeutic drugs reduces breast cancer recurrence by 30 percent.

Answer: D – The current white cell count is not affected by chemotherapy.

Explanation: The time required to clear circulating cells before the effect that chemotherapeutic drugs have on precursor cell maturation in the bone marrow becomes evident. Leukopenia is an abnormally low white blood cell count. Answers A-C pertain to red blood cells.

Answer: A – Epoetin alfa (Epogen, Procrit).

Explanation: Epoetin alfa (Epogen, Procrit) is a recombinant form of endogenous erythropoietin, a hematopoietic growth factor normally produced by the kidney that is used to induce red blood cell production in the bone marrow and reduce the need for blood transfusion. Glucagon is a pancreatic alpha cell hormone, which cause glycogenolysis and gluconeogenesis. Fenofibrate (Tricor) is an antihyperlipidemic agent that lowers plasma triglycerides. Lamotrigine (Lamictal) is an anticonvulsant.

Answer: A – Prostate cancer.

Explanation: Prostate tissue is stimulated by androgens and suppressed by estrogens. Androgen antagonists will block testosterone stimulation of prostate carcinoma cells. The types of cancer in options 2-4 are not androgen dependent.

Answer: A – ondansetron (Zofran).

Explanation: Chemotherapy often induces vomiting centrally by stimulating the chemoreceptor trigger zone (CTZ) and peripherally by stimulating visceral afferent nerves in the GI tract. Ondansetron (Zofran) is a serotonin antagonist that bocks the effects of serotonin and prevents and treats nausea and vomiting. It is especially useful in single-day highly emetogenic cancer chemotherapy (for example, cisplatin). The agents in options 2-4 are selective serotonin reuptake inhibitors. They increase the available levels of serotonin.

Answer: C – Intrathecally

Explanation: With intrathecal administration chemotherapy is injected through the theca of the spinal cord and into the subarachnoid space entering into the cerebrospinal fluid surrounding the brain and spinal cord. The methods in options A, B, and D are ineffective because the medication cannot enter the CNS.

Answer: B – Consolidation therapy

Explanation: Leucovorin is used to save or “rescue” normal cells from the damaging effects of chemotherapy allowing them to survive while the cancer cells die. Therapy to rapidly reduce the number of cancerous cells is the induction phase. Consolidation therapy seeks to complete or extend the initial remission and often uses a different combination of drugs than that used for induction. Chemotherapy is often administered in intermittent courses called pulse therapy. Pulse therapy allows the bone marrow to recover function before another course of chemotherapy is given.