Term
| What is the common suffix of barbiturates? |
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Definition
-barbital
Examples: amobarbital, phenobarbital, pentobarbital |
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Term
| How are barbiturates metabolized and excreted? |
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Definition
| Metabolized by the liver, excreted by the kidneys |
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Term
| Barbiturates interfere with which mechanism related to drug metabolism? |
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Definition
| Induce cytochrome P450, reducing the levels of both the barbiturate and any other drug metabolized by the liver |
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Term
| What are the 5 indications for use of barbiturates in psychiatry? |
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Definition
1. Anesthesia in ECT
2. Seizure prophylaxis or emergency treatment
3. Narcoanalysis (amobarbital interview)
4. Insomnia
5. Treatment of withdrawal from sedative-hypnotics |
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Term
| How are barbiturates used to treat hypnotic withdrawal? |
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Definition
| Give pentobarbital 200mg PO. Watch for signs of intoxication (sleepiness, slurred speech, nystagmus) after 1 hr. If not intoxicated, give 100mg pentobarbital q 2 hrs (max 500mg in 6 hrs). When intoxication occurs - this is the level of daily abuse. Give 30mg phenobarbital (longer t1/2) per 100mg pentobarbital. Taper dosage by 10% per day. |
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Term
| What are 3 common side effects of barbiturates? |
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Definition
Paradoxical dysphoria
Hyperactivity
Cognitive disorganization |
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Term
| What are 3 rare side effects of barbiturates? |
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Definition
Stevens-Johnson syndrome
Megaloblastic anemia
Neutropenia |
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Term
| How do barbiturates compare to benzodiazepines? |
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Definition
| Equally effective, but barbiturates have a lower therapeutic index |
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Term
| What are the 6 signs of barbiturate intoxication? |
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Definition
1. Confusion
2. Drowsiness
3. Irritability
4. Hyper- or a-reflexia
5. Ataxia
6. Nystagmus |
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Term
| What is the major concern of drug interactions in the use of barbiturates? |
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Definition
Additive effects of respiratory depression.
Use caution when used with other CNS drugs (e.g. antipsychotics, antidepressants) or with alcohol. |
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