Chapter 21 Neurology and the Neuromuscular System
Acetaminophen
MOA (Mechanism of Action) (Figure 21-1)







Important Notes

Overdose







Evidence
Analgesia
Acetaminophen versus Placebo for Treatment of Osteoarthritis

Acetaminophen versus Nonsteroidal Antiinflammatory Drugs for Treatment of Osteoarthritis

Acetaminophen plus Codeine versus Placebo

Acetaminophen Plus Codeine versus Acetaminophen Alone

Opioids
MOA (Mechanism of Action)



Receptor | Action |
---|---|
Mu (µ) |
Pharmacokinetics (Table 21-2)





• The glucuronides (being water soluble) are eliminated by the kidneys; renal disease can prolong and increase the effects of morphine.
• The glucuronides are water soluble; thus they do not readily cross the blood-brain barrier, but with high concentrations of drug, brain levels will increase.
Contraindications
Side Effects




Important Notes









Evidence
Opioids versus Nonsteroidal Antiinflammatory Drugs for Treatment of Renal Colic

Opioids for Treatment of Chronic Back Pain


FYI




α2 Agonists
MOA (Mechanism of Action)




Pharmacokinetics
Contraindications
Side Effects
Important Notes
Evidence
In Primary Open Angle Glaucoma and Ocular Hypertension

Inhaled Anesthetics
MOA (Mechanism of Action) (Figure 21-2)


Pharmacokinetics




• When inhaled anesthetics are administered, the drug must enter the lungs, then the blood, then the brain.
• For inhaled anesthetics to be eliminated, drug must exit the brain and other tissues, be carried to the lungs, and then exhaled.
• Vessel-poor tissues are slow to take up and release drug. Therefore vessel-poor tissues can act as a sink and slowly absorb drug at the early parts of an anesthetic procedure (lowering the drug levels) but then at the end of a long anesthetic procedure can release drug, prolonging elimination of the drug.

• Solubility is described for the blood and is called the blood/gas coefficient. The smaller the number, the less soluble the drug is in blood and therefore the faster it can change its partial pressure (because only a small amount of drug actually needs to be dissolved into the blood). The agents are ranked from fastest to slowest (lowest to highest solubility coefficient) as follows:
Side Effects

Important Notes





Advanced

FYI

Intravenous Anesthetics
MOA (Mechanism of Action)
γ-Aminobutyric Acid (GABA) (Figure 21-3)

Pharmacokinetics


Side Effects


Important Notes








Advanced


FYI

Local Anesthetics
MOA (Mechanism of Action)







Pharmacokinetics





Agent | Duration Plain (minutes) | Duration with Epinephrine (minutes) |
---|---|---|
2-Chloroprocaine | 20-30 | 30-45 |
Procaine | 15-30 | 30 |
Lidocaine | 30-60 | 120 |
Mepivacaine | 45-90 | 120 |
Prilocaine | 30-90 | 120 |
Bupivacaine | 120-240 | 180-240 |
Ropivacaine |