PART 3 / CH 26
Barbiturates and Benzodiazepines
Siobhan O’Neill
| Barbiturates/ Sedative-hypnotics | Benzodiazepines | |
|---|---|---|
| Urine Levels | >200ng/ml detectable | >200ng/ml detectable |
| Duration of (+) result | 2-20 days after use | 1-14 days after use |
| Serum Levels | variable | variable |
| Duration of (+) result | Depends on half-life. Shortest triazolam 1.5-5.5 hours; longest diazepam, clorazepate, flurazepam (20-100h) | |
| Acute intoxication | Sustained vertical and horizontal nystagmus, slurred speech, ataxia. Elevated mood, euphoria; labile mood; increased energy and self-confidence, irritability | Somnolence, slurred speech |
| (cont.’d) | Barbiturates | Benzodiazepines |
|---|---|---|
| Treatment of acute intoxication or overdose | Respiratory support, restraint if needed. | Respiratory support, restraint if needed. Flumazenil reversal is possible but sz risk. Bdz + EtOH can cause life threatening respiratory depression |
| Chronic use | Physiologic dependence, tolerance. | Physiologic dependence, tolerance. |
| Withdrawal: signs/sx | Onset at 12-24h up to 3-4d, based on half-life. Anxiety, tremors, nightmares, insomnia, anorexia, nausea, vomiting, postural hypotension, seizures, delirium hyperpyrexia. | Onset at 1-8d, based on half-life. Low dose benzo: anxiety, agitation, tachycardia, palpitations, anorexia, blurred vision, muscle cramps/spasms, insomnia, nightmares, confusion, psychosis, increased sensitivity to light and noise, paresthesias. High dose benzo: (supratherapeutic) as above, plus seizures, hyperpyrexia. |
| Treatment of withdrawal | phenobarbital taper | clonazepam taper monitor vital signs |