1. Sedative-Hypnotic Drugs and Alcohol
CHAPTER 12
Sedative-Hypnotic Drugs and Alcohol

2. Sedatives and Hypnotics
Sedatives are drugs used to induce a mild state of CNS depression characterized by both mental and physical calmness
Hypnotics are drugs used to induce and maintain sleep
The same drugs are used to induce both sedation and hypnosis; however, the dosage for inducing sedation is lower

3. Classification of Sedative- Hypnotic Drugs
Barbiturates – a drug family of chemically similar drugs with similar actions and features
Benzodiazepines – a drug family of chemically similar drugs with similar actions and features
Miscellaneous nonbarbiturates – a group of drugs with dissimilar chemical structures and pharmacologic features

4. Pharmacology of Barbiturates
Drugs classified as short, intermediate, and long-acting sedative-hypnotics
At low doses they increase the inhibitory effects of GABA
At high doses they act like general anesthetics, and can cause profound CNS depression and death in overdosage
Barbiturates are also anticonvulsants

5. Barbiturates to Know
Phenobarbital (Luminal) – long acting (6-12 hr) “hangover” – often used for epilepsy
Pentobarbital (Nembutal) – intermediate (4-6 hr)
Secobarbital (Seconal) – short (2-4 hr) help falling asleep

6. Effects of Barbiturates on the Sleep Cycle
Decrease stage 1, falling asleep
Increase stage 2, a lighter stage of sleep
Decrease stages 3 and 4 referred to as deep sleep or slow-wave sleep
Decrease REM sleep, and may cause REM rebound

7. Adverse Features of Barbiturates
Cause drug tolerance with chronic use and drug dependency with abuse
Can cause a severe type of physical drug addiction when chronically abused
The withdrawal reaction from barbiturates can be serious, resulting in convulsions and death
Drug interactions, induce microsomal enzymes to increase the rate of drug metabolism of all drugs metabolized by the microsomal enzymes

8. Reasons for decreasing use
Enzyme induction tolerance,  DMMS
Confusion in elderly
Automatism
REM rebound effect – nightmares
Dangerous with alcohol

9. Pharmacology of Benzodiazepines
Drugs classified as short, intermediate, and long-acting sedative-hypnotics
Drugs also produce antianxiety, skeletal muscle relaxing, and anticonvulsant effects
Act by increasing the inhibitory effects of GABA
Drugs do not induce the drug metabolizing microsomal enzymes

10. Effect of Benzodiazepines on the Sleep Cycle
Decrease stage 1, falling asleep
Increase stage 2
Decrease stages 3 and 4
Do not significantly decrease REM sleep
Benzodiazepines are considered safer drugs than the barbiturates, especially in overdosage

11. Benzodiazopines to Know
Most frequent sleeping pill in hospital
Flurazepam (Dalmane) – long acting (1-2 days)
Temazepam (Restoril) – intermediate (8-10 hr)
Triazolam (Halcion) short
Decrease restfull sleep (stage3-4) not REM – Does not induce DMMS

12. Miscellaneous Nonbarbiturates
Zolpidem and zaleplon are short-acting hypnotics that do not disrupt the sleep cycle
These drugs increase the inhibitory effects of GABA but differently than other drugs
Both drugs are considered to be safer than other hypnotics and are at low risk for abuse
Side effects include dizziness, headache, GI disturbances, and mental confusion

13. To Know
Zolpidem (Ambien) short acting (2-3 hr) doesn’t alter stage 3-4 or REM
Zaleplon (Sonata) similar to Ambien

14. Alcohol Classified as a CNS depressant drug
Unlike other drugs, alcohol provides nutritional calories
Like other drugs of abuse, alcohol causes development of drug tolerance, dependency, and withdrawal reactions
Most of the pharmacology of alcohol centers around its chronic use, abuse, and toxicology

15. Alcohol Metabolized at a constant rate Toxic effect:
10-15 cc alcohol = oz vodka = beer = glass wine
Toxic effect:
Low dose = carbohydrate
High dose or with Tylenol = Toxic

16. Disulfiram (Antibuse)
Used to treat alcoholism and deter drinking
Disulfiram inhibits metabolism of alcohol, allowing acetaldehyde to accumulate
Increased acetaldehyde produces severe nausea, vomiting, headache, and hypotension
Alcoholics take the drug on a daily basis, knowing that if they drink any alcohol they will become violently ill