12. Cancer and Antiemetics Flashcards
What is Antiemetics drugs for?
drugs that are used to against vomiting and nausea
Which cancers are the most lethal cancers in men and women?
Lung cancer and breast cancer. They are most likely of all cancers to spread to the eye.
What are the different anti-metabolites drugs for treating cancers?
- Methotrexate [Trexall] “MOST COMMON”
- Trimethorprim [Primsol]
- Pyrimethamine [Daraprim]
- Pemetrexed [Alimta]
The indication for taking Methotrexate (anti-metabolites) are for ______, ______ and ______.
Rheumatoid Arthritis, Psoriasis (dry, itchy patch on skin) and Choriocarcinoma (cancer developed from placenta).
Do we use Methotrexate to suppress the immune system?
Yes, it’s an Immunosupressant.
The mechanism of action of Methotrexate is to act as a _____ analogue, inhibits dihydrofolate reductase (DHFR), thus preventing formation of _____.
It also inhibits ______ proliferation.
folic acid, tetrahydrofolate (FH4), lymphocyte
What are some common adverse effects of taking Methotrexate?
Photosensitivity, pruritis (itchy), anemia, dizziness
What is the severe adverse effect of taking Methotrexate?
Neurotoxicity - damage to the nervous system
T/F Methotrexate has a “BLACK BOX” warning.
True.
- Death reported: monitor bone marrow, liver, lung & kidneys; opportunistic infections
- Potentially fatal myelosupression with NSAIDs
T/F Taking Methotrexate with NSAIDs, Sulfonamides, Ciprofloxacin and Penicillins will increase elimination of the drug, thus, reducing drug effects in the body.
False. It reduces the drug elimination in the body, which it produces additive effects to the drug.
T/F Taking Cyclosporine with Methotrexate reduce hepatic metabolism, therefore, increases the concentration in the body. *May increase the side effects
True
T/F Taking Ganciclovir (anti-viral) with Methotrexate will increase bone marrow suppression (myelosuppression).
True, It adds to the myelosupression effect of the drug.
Myelosuppression causes decrease in the production of red blood cells, white blood cells and platelets
T/F Taking Systemic Corticosteroids with Methotrexate will not suppress the immune system even more.
False. It has additive immunosuppression effect.
Taking Tetracyclines in the presence of Methotrexate will _____ Methotrexate levels.
elevate
Nearly _____% of all patients who undergo chemotherapy experience nausea or vomiting; incidence and severity depend on drug type, dose, route and schedule of administration
70-80
Key receptors involved in the emetic response are D2 and 5HT-3
D2, 5HT-3
T/F Chemotherapeutic drugs only affects the CNS.
False.
Chemotherapeutic drugs can also act peripherally by causing cell damage in the GI tract and releasing serotonin from the enterochromaffin cells of the small intestinal mucosa. The released serotonin activates 5-HT3 receptors on vagal (CN X, heart and digestion) and splanchnic afferent fibers, which then carry sensory signals to the medulla, leading to the emetic response (vomiting and nausea).
Methotrexate has high, moderate or mild emetic potency?
mild
What is an Antiemetics drug?
Promethazine [Phenergan]
What is Promethazine (antiemetic) use for?
nausea and vomiting, sedation, [Allergy], [Motion sickness]
What is the dosage Promethazine use for nausea and vomiting vs. sedation.
twice as much med for sedation than for nausea and vomiting.
25-50mg qd for sedation
12.5 - 25 mg q4-6h
T/F Promethazine is a non-selective central and peripheral H1 antagonist.
True
Common Adverse effects of Promethazine includes drowsiness, blurred vision, confusion, dermatitis and ______.
photosensitivity
serious adverse effects of Promethazine are
Thrombocytopenia (low platelet count) and agranuloctosis (decrease granulocytes)
Is Promethazine have “Black Box” Warnings?
Yes,
Respiratory depression, Severe Tissue Injury (Gangrene) may occur.
Taking Promethazine with Macrolides, Azoles and CAIs will cause what?
Prolonged OT segment. bad for heart.
Taking Pilocarpine in the presence of Promethazine will cause what?
Pilocarpine antagonizes Promethazine
Promethazine can impaired the metabolism of ______.
Beta-blockers
Taking Anticholinergics, Sedating Antihistaminics, Olopatadine Nasal in the presence of Promethazine will produce a what effect?
Additive effect
What can happen if you taking Omega-6 fatty acid with Promethazine?
Can cause seizures.
Can you give your patient Proethazine if he/she has angle closure glaucoma?
No. “CAUTION”
