Pharmacology - Analgesics NSAIDS (Practice)

1. Mechanism of action questions regarding analgesic, antipyretic and effects on bleeding:
Analgesic effects: aspirin inhibits the synthesis of prostaglandins

Antipyretic effects: aspirin inhibits PG synthesis in the hypothalamic temperature regulation center

Bleeding time: inhibit synthesis of thromboxane A2 preventing platelet synthesis

2. A 2nd type of question has to do with pharmacological or toxic effects of aspirin: you get to pick which of the list is or is not associated with aspirin. Therapeutic effects of aspirin include pain relief, antipyretic effects, antirheumatic and anti-inflammatory effects. Adverse or toxic effects include all of the following: occult bleeding from the GI tract, tinnitus, nausea and vomiting, acid-base disturbance or metabolic acidosis, decreased tubular reabsorption of uric acid, salicylism, delirium, hyperventilation, etc.

3. A third type of question focuses on the difference between 1) aspirin and acetaminophen, 2) aspirin and other anti-inflammatories like prednisone, and 3) between aspirin and ibuprofen:
1) Acetaminophen lacks anti-inflammatory activity, is hepatotoxic, and does not cause GI upset
2) Anti-inflammatories like prednisone, hydrocortisone, triamcinolone etc. are steroids and do not act primarily by PG inhibition
3) Ibuprofen causes much less GI irritation
4) Diflunisal (Dolobid) has a longer half-life than aspirin, acetaminophen and ibuprofen

4. Newer versions of the boards have questions about COX-2 inhibitors like vioxx. (Which of the following is a COX-2 inhibitor?)

5. These old questions focus a lot on aspirin. Nowadays, acetaminophen and ibuprofen are used much more commonly than aspirin, because of the many side effects of aspirin that turn up in these kinds of questions. So since aspirin is the comparator prototype drug, reviewing these questions are still useful. But expect newer questions asking you to know:

a. Acetaminophen causes liver toxicity, especially when combined with alcohol or taken in excess of 4 gr/day.
b. Acetaminophen is the drug of choice for the feverish child (they usually ask the reverse, which is which drug should be avoided in the feverish child (aspirin- increased risk of Reye’s syndrome)