Group 6 Flashcards
(16 cards)
Hyalurinodase source and mechanism of action
Derived from bovine/ovine testicular tissues.
MoA: Degrades hyaluronic acid to increase tissue permeability, enhancing drug/fluid absorption.
List three clinical uses of hyaluronidase.
- Treating extravasation injuries.
- Reversing dermal filler complications.
- Enhancing absorption of subcutaneous drugs (e.g., emergency medications).
What is the antidote for hyaluronic acid filler complications?
Hylenex® (150 units)** injected into the affected area. Repeat hourly if needed.
What precautions are needed with hyaluronidase?
Avoid use near tumors (risk of spread) and in infections. Monitor for allergic reactions.
How is infection managed after filler complications?
Amoxicillin-Clavulanate 625 mg PO Q8H for 7–10 days
What is leucovorin’s role in methotrexate toxicity?
It bypasses DHFR inhibition to restore folate levels, protecting cells from methotrexate toxicity.
When must leucovorin be administered after methotrexate?
Within 6–24 hours of methotrexate administration, continued until plasma methotrexate levels are non-toxic.
What drug is combined with leucovorin in severe methotrexate toxicity?
Glucarpidase (lowers blood methotrexate levels rapidly).
What contraindications apply to leucovorin?
Hypersensitivity to folinic acid or formulation components.
How does arsine gas cause toxicity?
It induces massive hemolysis by inhibiting ATP-producing enzymes (e.g., pyruvate dehydrogenase).
What are acute vs. chronic symptoms of arsenic poisoning?
*Acute:** Vomiting, diarrhea, arrhythmias, hypotension.
- Chronic: Hyperpigmentation, Mees lines, peripheral neuropathy, cancer.
What chelating agents are used for arsenic poisoning?
- Dimercaprol (BAL): 3–5 mg/kg IM every 4 hours.
- DMSA (Succimer): Oral alternative.
- Penicillamine: 100 mg/kg/day PO if no penicillin allergy.
Why is ipecac/gastric lavage contraindicated in arsine gas exposure?
Risk of increasing arsine gas release in the stomach.
What is a key difference between hyaluronidase and leucovorin in clinical use?
Hyaluronidase enhances drug absorption/tissue repair, while leucovorin counteracts folate-antagonist toxicity.
What parameters are monitored during arsenic poisoning treatment?
CBC, renal function, serum/urine arsenic levels, and recurrence of hemolysis.
What is a shared precaution for all three drugs?
Hypersensitivity monitoring (allergic reactions are possible with hyaluronidase and leucovorin; arsenic chelators like BAL have side effects).
