Antianxiety agents and drugs to treat CNS disorders

Drugs to treat CNS disorders

• Antipsychotic agents

• Anti-depressive agents

• Drugs to treat bipolar disorder

Antianxiety Agents

• AKA?

• Sedative-hypnotic agents

• Produce varying degrees of CNS depression depending on dose

• Same drug can produce both effects depending on dose

Sedative?

• Small Dose, mild CNS depression- reduces activity, some anxiolytic-effects ****

• Can help lower pain threshold and potentiate analgesic agents

Hypnotic?

Large dose-greater CNS depression (induces sleep)

Types of Antianxiety Agents ?

• Benzodiazepines***: common prescribed antianxiety drugs

• Barbiturates

Types of Antianxiety Agents ?

• What are the two types of NON?

• benzodiapine: nonbarbiturate-sedative hypnotics

• benzodiazpone receptor hynotics

Types of Antianxiety Agents ?

• Receptor Type?

• Melatonin R. agonist (hypontic)

• Orexien R. antatgonist- hypontic

• Muscle Relaxer

Benzodiazepine Agents

• Common endings?

• Generic drug name (trade name) 4

1. Azepma- azolma

Name

1. Alprazolam (xanax)

2. Diazepam(Valium)

3. Lorazepam (ativan)

4. Triazolam (halcion)

Benzodiazepine Pharmacokinetics:

• Oral Route

• Distrubtion

• Other dose forms

1. Tablets- capsules, oral solution - well absorbed

2. Across the blood brain barrier into cerebrospinal fluid (rate affected by protein binding, lipid solubility, ionization)

Benzodiazepine Pharmacokinetics:

• Other dose forms

1. Rectal gel, injectable

• IM: Slow erratic, unpredictable result

• IV: Rapid and predictable results (ideal for conscious sedation)**

• Metabolism

By liver - affected by drugs inhibiting hepatic metabolism and hepatic disease

• Excretion

By kidneys

Benzodiazepine Pharmacokinetics:

• Mechanism of Action (MOA)

• Enchance or facilate the action of aminobutyric acid (GABA)

Mechanism of Action (MOA)

• Define GABA?

• Is a major inhibitory transmitter in CNS

• AKA: slows down the brain by blocking specific signals - produces calming effect

Benzoiazepines: Pharm Effect

• Behavioral effects?

• Vary in?

Similar actions but in potency

• Low dose: anxiety and panic reduction

• High dose: drowsiness and sleep

• Repeated doses: reduce REM sleep, interfere with restorative sleep

Antiseizure effects

• Increase?

• Diapzepam?

Def: seizure threshold

• parentally used to prevent seizures, treat status epilepticus

Antiseizure effects

• Colnazepam

• Muscle relaxtion- reduces?

Def: Oral helps prevent partial seizures

• pain in skeltal muslces

• muscle spasticy caused by cerebral palsy and paralegia

BENZODI:

Adverse reactions

• CNS effects?

• Common in?

• *** Depression-fatigue- drowisness, muscle weakness, ataxia- ligheadedness, dizziness

• in elderly perosn, can build up to tolerance over time

Adverse reaction

• Opposite effects

Can occur - talkativeness, anxiety, nightmares, hyperactivit -increases muscle spasiticty

Adverse reactions

• Dental considerations

• Used in dentistry for conscious sedation -midazolam has slight advantage over diazepam due to shorter half-time)

Adverse reactions:

• Anterograde amnesia

• Therapeutic effet

• Patients should be cautioned against signing important papers or make important decisions

• can make patients forget unpleasant dental procedures- oral triazolam

Adverse reactions

• Thrombophlebitis

• with parenteral diapzema

• can cause apnea, hypotension, bradycardia, cardiac arres, blood clots

• dental providers admin parenteral diazepam for conscious sedation require special training***

Adverse reaction:

• Respiratory depression

• other effects

• Rare but exacerbated by opioids -alcohol, eldery patients

other effects

• GI upset, diffculty urinating-allerfic reactions -mild

Adverse reaction

• Pregnancy and lactation

• Black Box Warning: Abuse, addiction, misuse, physical dependence, withdrawal reactions.

• Pregnancy and lactation

• 1st trimester: Increased risk of congenital malformation (cleft lip/palate, microcephaly, GI/CV abnormalities).

• Pregnancy and lactation

• Near-term: "floppy infant syndrome" (hypoactivity, hypotonia, hypothermia, apnea, feeding problems).

• Most are FDA Pregnancy Category D.