Antipyretics

Question 1

What is a fever?

Answer 1

Body’s response to fighting some invasive antigen; regulated rise in core body temperature in response to a physiologic threat

Question 2

How is a fever mediated?

Answer 2

Thermoregulatory center of the hypothalamus, normal body temp is regulated within the “set point” of 36.5-37.5

Question 3

What are pyrogens?

Answer 3

Substances that raise body temperature through interaction with hypothalamus neurons

Question 4

What are cytokines?

Answer 4

Most important pyrogens

Question 5

Endogenous pyrogens

Answer 5

Come from the immune response (interleukin, tumor necrosis factor, etc.)

Question 6

Exogenous pyrogens

Answer 6

Come from microbial origin, induce host cells to produce endogenous pyrogens (MACROPHAGES)

Question 7

Anterior Hypothalamus

Answer 7

Endogenous cytokines interact with the anterior hypothalamus to active phospholipase and release a substrate to produce PGE2 which resets the hypothalamic set point to produce a fever

Question 8

Physiologic and Endocrine Alterations of Pyrogens

Answer 8

Fever, anorexia, lethargy, altered synthesis of glucagon, ACTH, insulin, cortisol, etc.

Question 9

Neonatal Temperature Regulation: Causes of Neonatal Fever

Answer 9

Infection, dehydration, HERPES (within a few days), maternal fever in labor, maternal epidural, drug withdrawal, drug effect (prostaglandin)

Question 10

Purpose of Fever Control

Answer 10

Provide symptom relief, decrease metabolic function, and reverse fever induced mental dysfunction

Question 11

Acteaminophen: Classification

Answer 11

Analgesic, antipyretic

Question 12

Acetmainophen:

Mechanism of Action

Answer 12

Prostaglandin inhibitor to block pain impulse and hypothalamic heat-regulating center. Non-selective COX-inhibitors

Question 13

Acetaminophen:

Dosing

Answer 13

Based on PMA

Question 14

Acetaminophen:

Adverse Effects

Answer 14

Hepatotoxicity (usually with supratherapeutic dosing), rare skin reactions, anemia, constipation

Question 15

Acetaminophen:

Monitoring

Answer 15

LFTs

Question 16

Acetaminophen:

Characteristics

Answer 16

• Recommened agent for fever control in infants
• Little anti-inflammatory effect
• Well absorbed
• Metabolized in the liver, excreted in the urine
• Efficacy in pain control still being studied
• PDA Closure: unclear efficacy

Question 17

Acetaminophen:

Normal Dosing

Answer 17

Oral: 10-15 mg/kg/dose Q4-6 hours PRN
(MAX: 75 mg/kg/d)

Rectal: 80 mg Q6 hours (MAX 320 mg/d)

Question 18

Ibuprofen:

Classification

Answer 18

NSAID

Question 19

Ibuprofen:

Mechanism of Action

Answer 19

Prostaglandin synthesis inhibitor

Question 20

Acetaminophen:

Monitoring

Answer 20

Renal impairment, liver function

Question 21

Ibuprofen:

Dosing

Answer 21

Look in Lexicomp

Question 22

Ibuprofen:

Adverse effects

Answer 22

Gastritis, nausea, prolonged bleeding time, anemia, renal injury, hepatic injury, rare-skin reactions

Question 23

Ibuprofen:

Monitoring

Answer 23

CBC, electrolytes, liver enzymes, UOP, BUN, creatinine