8 - Barbiturates

Question 1

What type of drug are barbiturates?

Answer 1

Nonselective CNS depressants

Question 2

What can influence pharmacological responses of barbiturates?

Answer 2

• Route of administration, dose
• PK properties of each individual compound
• Patient factors (age, physical and emotional state)
• Concomitant use of other medications

Question 3

Onset of barbiturates based on route of administration

Answer 3

IV > IM > oral = rectal

Question 4

Describe the absorption of barbiturates

Answer 4

Sodium salts undergo rapid dissolution and absorbed more quickly than corresponding free acids

Question 5

Metabolism and excretion of barbiturates

Answer 5

• Metabolism in liver through conjugation

- Excreted by kidneys

Question 6

What influences metabolic elimination of barbiturates?

Answer 6

• Age
• Hepatic conditions
• Interactions w/ other drugs

Question 7

Therapeutic index of barbiturates is _____

Answer 7

Narrow

Question 8

Use of barbiturates

Answer 8

• W/ analgesics for mild to moderate headaches

- IV for management of status epilepticus or acute seizure episodes

Question 9

Rate the 3 barbiturates used in the lab based on onset (shortest to longest), half life (shortest to longest), and duration (shortest to longest)

Answer 9

• Onset = pento < amo < pheno
• Half life = amo (8-42 h) < pento (15-48 h) < pheno (80-120 h)
• Duration = pento < amo < pheno

Question 10

What happens to absorbance of a barbiturate at 260 nm after hydrolysis?

Answer 10

Will decrease

Question 11

What does a lower R value mean?

Answer 11

Easier to hydrolyze (pheno < amo < pento)

Question 12

Why should you measure all the samples for the same part of the experiment together?

Answer 12

Improve measuring accuracy and minimize potential sample contamination