Episode 021: Pharmacology 101: Part 2
Picture this: it's day 1 of fellowship and your attending needs you to "get consent for treatment." Huh? How do you educate your patient? We share our tips!
In this episode, we discuss important considerations, including “does my patient need a port?”, “what if drugs extravasate?”, “how do I keep side effects of drug classes straight?!”
*The resources we share are our OWN opinions. Naming of resources are not endorsements. We are not sponsored by any of these entities.
Pharmacology 101:
Irritant vs. Vesicant:
Each drug is deemed one of these based on the degree of tissue damage that can result if drug extravasates under skin.
Vesicant: needs central access
Irritant: can be given peripherally
Does my patient need a port/picc?
If vesicant, then usually get
If they need to do a continuous infusion for several days (e.g. 5-FU), they need a port
Some patients will request one because of difficult access
Advantages of ports:
Easy access for labs
Easy access for chemotherapy/fluids
Disadvantages:
Risk of infection
Risk of thrombosis
General overview of chemotherapy side effects:
Going to target the fastest growing cells in the body, which includes cells that line the GI tract, skin, hair/nails, and blood cells
Therefore side effects are related:
GI: nausea/vomiting, diarrhea (sometimes constipation), decreased appetite, taste changes
Low blood counts
WBC nadir ~10-14 days (generally), and recover 21-28 days after chemo
What about unique side effects of chemotherapy classes? How do we keep them straight?
We love keeping “Chemoman” from the USMLE study days in mind!
Anthracycline
MOA:Topoisomerase inhibitors
Ends in “rubicin”
You might hear people call doxorubicin the “red devil”
Used in lots of cancers
Hair loss occurs with this one
Known to cause cytopenias and associated with higher nausea potential
Unique side effects:
Heart failure (always get baseline echo!)
Development of MDS and leukemia
Alkylating agents
MOA: Drugs add alkyl group to the guanine base of the DNA molecule, preventing linking of strands
End in “fosfamide”
Ifosfamide or cyclophosphamide (AKA cytoxan)
Used in lots of cancers
Known to cause cytopenias and hair loss
Unique side effects:
Secondary MDS or leukemia possible
Ifosfamide = neurotoxicity = methylene blue antidote
Cyclophosphamide = hemorrhagic cystitis due to acrolein byproduct accumulation = prevent by giving mesna to protect bladder
Antimetabolites
MOA: Purine analog, pyrimidine analog, folate antagonists; therefore prevent production of base pairs or binds instead of normal base pairs
End in “abine” - capecitabine, cytarabine, gemcitabine, cladribine, fludarabine
Also 5-FU and 6-MP in this category so “number followed by dash”
Unique side effects:
Think bone marrow suppression in this category
Platinum agents
MOA: Believed to cause cross-linking of DNA
End in “platin”
Associated with high risk of neuropathy
Unique side effects:
Cisplatin:
Nephrotoxicity
Ototoxicity
High risk of nausea; need special prophylaxis
Carboplatin: cytopenias
Oxaliplatin: higher rates GI side effects
Microtubule agents
MOA: Impair microtubule function, therefore impacting cell division
End in “taxel” or vincristine/vinblastine (“V-stine”)
Unique side effects:
Neuropathy