Drug Identification - NCLEX-PN

Levodopa (L-DOPA), a common treatment for Parkinson's disease, is generally given in combination with carbidopa or another peripheral dopa-decarboxylase inhibitor. This is because levodopa alone will stimulate dopamine receptors in the GI tract and the chemotrigger receptor zone (CTZ) in the brain, resulting in nausea, vomiting and anorexia. A peripheral dopa-decarboxylase inhibitor prevents levodopa from being prematurely converted into dopamine in the adrenal glands or other peripheral tissues.

Adalimumab is a tumor necrosis factor alpha (TNF-alpha) inhibitor. This class of drugs suppresses response to TNF-alpha, a potent pro-inflammatory cytokine. Inhibition of folic acid metabolism is the method of action of methotrexate. Reversible inhibition of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) is the mechanism of non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen. Rheumatoid arthritis drugs such as rituximab, and almost all drugs that end in -mab, including adalimumab function as monoclonal antibodies.

The correct answer is "insomnia," as steroids are known to increase patients' vigilance and energy levels, thereby frequently making it difficult for patients to fall asleep and/or stay asleep while taking their steroid medication. The other choices are incorrect. Decreased appetite is not a side effect of taking steroid medications. Patients on steroids often have increased appetite. Hyponatremia and hyperkalemia both are not side effects of taking steroid medications. Hypernatremia and hypokalemia are more common side effects of steroids. Hypertension, rather than hypotension is a known side effect of steroid use.

The correct answer is "acetaminophen." This is the correct answer because acetaminophen, also known as Tylenol, is initially metabolized into a hepatotoxic intermediate (it transiently becomes a reactive oxygen species, which can cause liver hepatotoxicity). As such, in patients who already have pre-existing liver disease who are already more prone to liver injury from substances and diseases that affect the liver, it is prudent to avoid medications like acetaminophen that have a known potential to cause liver damage.

Meloxicam, ibuprofen, naproxen, and ketorolac are all examples of non-steroidal anti-inflammatory drugs (NSAIDs). These medications have the potential to cause renal damage or gastrointestinal damage if used in excess, but do not have the known hepatotoxic properties that acetaminophen does.

The correct answer is "meperidine." Meperidine, a potent opioid analgesic, also known as Demerol, is one of the only opioids that produces dilated pupils, rather than constricted, "pinpoint" pupils. A way to remember this is to remember the phrase, "Demerol Dilates." The other choices are incorrect. Acetaminophen has no known effect on pupil size. Morphine, oxycodone, and hydromorphone, all opioid analgesics, are known to constrict the pupils.

Ciprofloxacin belongs to the fluoroquinolone class of antibiotics. Other antibiotics in this class include norfloxacin, levofloxacin, and nadifloxacin.

Fluoroquinolones (the most commonly prescribed of which is ciprofloxacin) carry a risk of all of the following adverse effects: sudden tendon rupture or tendonitis, hepatotoxicity or liver failure, seizures, and permanent peripheral neuropathy. Other adverse effects include C_lostridium difficile_ associated diarrhea, bone marrow suppression, Steven-Johnson's Syndrome, tremors, and psychosis. The majority of these adverse effects are seen in higher numbers in children and the elderly.

Tetracycline antibiotics are contraindicated in pregnant women and small children due to their tendency to irreversibly stain developing teeth. They can also affect fetal bone growth and so are pregnancy category D (known incidence and risk of fetal harm).

Of the antibiotics listed, amoxicillin is the only one considered safe in pregnancy. Doxycycline and gentamicin are both pregnancy category D (known to cause fetal harm). Levofloxacin is category C (fetal harm can not be ruled out).

All of the drugs listed frequently cause C_. difficile_ overgrowth and C_. difficile_ associated diarrhea except vancomycin, which is often used as a treatment for persistent C_. difficile_ infections.

Penicillins belong to a larger class of antibiotics known as beta-lactams. These antibiotics inhibit cell-wall synthesis and are exclusively used to treat Gram positive bacteria. They are not effective against Gram negative bacteria or fungi.

Fluoroquinolones are considered to be the treatment of choice for E . coli infections due to their effectiveness in relieving diarrhea and minimal serious adverse effects. Aminoglycosides and beta-lactam antibiotics may also be effective, as a second choice.

Gentamycin, an antibiotic and aminoglycoside, inhibits protein synthesis of gram-negative bacteria. It treats severe systemic infections. It may cause ototoxicity and nephrotoxicity, as well as anorexia, nausea, vomiting, and diarrhea. Diaphoresis is not a common side effect of gentamycin.

The correct answer is "inhibition of topoisomerase II," as this is the mechanism of action of fluoroquinolone antibiotics, such as levofloxacin.

The other choices are incorrect for the following reasons:

Blockage of tRNA-ribosome-mRNA complex binding is the mechanism of action of tetracycline antibiotics.

Disruption of mycolic acid synthesis is the mechanism of action of various anti-fungal agents.

Disruption of peptidoglycan cross-linkage is the mechanism of action of vancomycin.

Inhibition of peptidoglycan synthesis is the mechanism of action of beta-lactam antibiotics.

Acyclovir is converted to acyclovir-triphosphate and incorporated into the synthetic pathway for viral DNA as a guanosine molecule. The initial phosphorylation of acyclovir is carried out by viral thymidine kinase. Acyclovir has a higher affinity for viral thymidine kinase than mammalian thymidine kinase. Therefore, acyclovir is specifically effective in virally infected cells.

All of the drugs are antifungal agents but only flucytosine has been associated with bone marrow suppression and synergizes with other drugs which suppress bone marrow functions. Miconazole and ketoconazole may produce hepatotoxicity, gastro-intestinal upset and headaches. Amphotericin B may produce nephrotoxicity while itraconazole is associated with gastro-intestinal upset and rare liver dysfunction.

Amantadine only works after viral attachment to the cell, preventing viral uncoating. It is also believed to interfere with viral mRNA production. Amantadine is effective against influenza virus A.

All the listed agents are synthetic analogues, except interferon, which is a glycoprotein produced by many types of mammalian cells. It has been shown to be useful in treatment of hepatitis, papilloma viruses, hairy-cell leukemia and AIDS-related Kaposi's sarcoma. Idoxuridine, as its name implies, is a synthetic pyrimidine analog, which inhibits viral DNA polymerase. Zidovudine and zalcitabine are also synthetic pyrimidine analogs but they inhibit reverse transcriptase and act as chain terminators. Acyclovir is a synthetic purine analog which requires viral thymidine kinase to be converted to an active phosphorylated form, which then, inhibits viral DNA polymerase.

Loa loa is an extra-intestinal nematode, which may migrate to the CNS, causing encephalitis. Diethylcarbamazine is successful in treating Loa loa but will exacerbate the encephalitis unless steroids are used first to treat the symptoms of the encephalitis. Other side effects of diethylcarbamazine may be due to rapid death of nematodes and release of various toxic substances. Symptomatic treatment might be appropriate with a number of pharmacological classes, but most symptoms will resolve as the body is cleared of dead and dying nematodes.

Amantadine affects the central nervous system, producing mild, reversible disturbances. High dosages have been reported to induce seizures