Test 4: Multimodal Specific Drugs to Know Flashcards
What are NSAIDs used for?
-Treatment of mild-moderate post-op pain
-Pain r/t inflammation
-Most common analgesia adjuncts
-NSAIDs + Opioids = synergistic effect (!)
-Antipyretic, analgesic, and anti-inflammatory
-Inhibits cyclooxygenase (COX)
-Most are weak acids with pKa between 4-5
What is COX 1?
COX = enzyme that makes thromboxane, prostaglandins, and prostacyclins.
-Widespread throughout the body and necessary for homeostasis
-Responsible for platelet aggregation, gastric mucosal integrity, and renal function
-Inhibition causes gastric irritation, renal microvascular constriction, and platelet inhibition
What is COX 2?
COX = enzyme that makes thromboxane, prostaglandins, and prostacyclins.
-Inducible enzyme that releases prostaglandins in the presence of inflammation
-Mediates pain, fever, and carcinogenesis
-Inhibition causes analgesic effects
-Modulation of cell proliferation
-No issues with hemostasis and less GI issues.
What are the pharmacokinetics of Celecoxib (Celebrex)?
-Absorption: Bioavailability unknown
-Distribution: 97% protein bound
-Metabolism: Extensively hepatically metabolized via CYP450 to inactive metabolites
-Half-life = 11 hours
-Dose: 200 mg QD or 100 mg BID
-Caution use in patients with Hx of GI bleed
What is the MOA of Celecoxib (Celebrex)?
-COX-2 selective NSAID (reversible)
-Decreases formation of prostaglandin precursors
-Reduces inflammatory symptoms
-Relieves pain
What are the CNS effects of Celecoxib (Celebrex)?
Headache
What are the Respiratory effects of Celecoxib (Celebrex)?
-Potential for bronchoconstriction due to conversion of arachidonic acid to the precursor of leukotrienes.
-Technically contraindicated in asthmatics, even though they usually tolerate it well.
What are the cardiovascular effects of Celecoxib (Celebrex)?
-Can start or worsen hypertension
-DIC in children with systemic onset juvenile RA
-Can lead to MI formation
What are the uses of Celecoxib (Celebrex)?
Useful in arthritis, gout, dysmenorrhea, and orthopedic surgeries.
-Treatment of acute surgical pain, chronic pain syndromes, and cancer pain
-Often used in combination with other analgesics
What are the risks associated with long-term use of Celecoxib (Celebrex)?
Concern for duodenal ulcers, hemorrhage, or MI (if taking every day for long periods of time)
What are the contraindications / cautions to the use of Celecoxib?
-C/I if hypersensitivity to sulfonamides (contains sulfa), asthma, or hypersensitivity to NSAIDs/ASA.
-Caution in pts taking warfarin or phenytoin – cotherapy increases warfarin or phenytoin levels.
What are the Onset and Peak times of Ketorolac (Toradol)?
-IM Onset: 30min with Peak 2-3 hrs
-IV Onset: 15 min with Peak 2 hrs
-Well absorbed via PO
Would be administered at the end of the case - peaks in PACU. Ask if surgeon is concerned with use and with oozing.
Often in PACU standing orders - notify PACU RN of when you dosed.
What is the Distribution & Metabolism of Ketorolac (Toradol)?
Distribution:
-DOA 6-8 hrs
-Crosses placenta
-Enters breast milk
-99% protein bound
Metabolism: Hepatic
Excretion: Renal
What is the dose of Ketorolac (Toradol)?
Adults > 50 kg
-30mg IM = 12 mg Morphine = 100 mg Demerol.
-Should not be administered beyond 5 days (used for short-term, acute post-op pain)
-Very potent.
What is the MOA of Ketorolac (Toradol)?
-Non-selective COX inhibitor (COX 1 & 2)
-Inhibits prostaglandin synthesis by decreasing COX = decreased prostaglandin precursors
Causes platelet inhibition. Potent analgesic with moderate anti-inflammatory properties.
What are the CNS effects of Ketorolac (Toradol)?
-HA
-Hallucinations with concomitant use of psychoactive drugs
What are the Respiratory and CV effects of Ketorolac (Toradol)?
Respiratory:
-Bronchospasm
-Anaphylaxis
Cardiovascular:
-Edema (rare)
-HTN
What is important to know regarding Ketorolac and renal function?
-C/I with renal failure (renal excretion) and high grade renal insufficiency.
-Prolonged clearance with opioids on board
-½ life prolonged 30-50% in elderly. Look at Creatinine clearance. Dec dose in elderly due to decline in renal function.
What are contraindications for the use of Ketorolac (Toradol)?
-renal failure
-coagulopathies
-PUD
-GIB
-asthma
-hypersensitivity to NSAIDS
-surgery with high risk of bleeding
-Controversy with orthopedic procedures
Why is Ketorolac controversial with orthopedic procedures?
Interrupts normal prostaglandin effects on osteoblast and osteoclast activity that promote bone healing.
What are the pharmacokinetics of acetaminophen?
Absorption:
-IV onset 10 minutes
-Almost entirely neutral and absorbs rapidly from duodenum.
Distribution:
-DOA 4-6 hours
-8-43% protein bound
Metabolism:
-Hepatic
-Active metabolite: acetylimidoquinone
-1/2 life = 1-3 hours