Etomidate  -Intravenous Anesthetics

- A nonbarbiturate anesthetic used primarily to induce surgical anesthesia.
- It does not produce analgesia.
- Etomidate has minimal effect on the cardiovascular system and respiration during induction of anesthesia.
- Like the barbiturates, etomidate decreases cerebral blood flow, cerebral metabolic rate and intracranial pressure.
- No changes in hepatic, renal or hematologic function have been reported.
- Myoclonic muscle movements are relatively common.
- Postoperative nausea and vomiting are more common with etomidate than with barbiturates.

Stages of anesthesia

Stage I

Analgesia

Still conscious but drowsy

Stage II

Excitement stage

Loss of consciousness, however, irregular ventilation may be present which affects absorption of inhalation agents.

Reflexes may be exaggerated.

This is a very dangerous stage

Stage III

Surgical anesthesia

Loss of spontaneous movement

Regular, shallow respiration

Relaxation of muscles

Stage IV

Medullary paralysis

Death

Methicillin

Methicillin is an antibiotic related to penicillin and other beta-lactam containing antibiotics. It is often used to treat infections caused by bacteria carrying an antibiotic resistance, e.g., staphylococci. As methicillin is deactivated by gastric acid, it has to be administered by injection.

Uses Methicillin serves a purpose in the laboratory to determine antibiotic sensitivity in microbiological culture.

Ethosuximide (Zarontin): use in absence seizures (may exacerbate tonic-clonic seizures)

Mechanism: ↓ T-type Ca currents in thalamic neurons, inhibits bursts of APs, ↓ synchronous neuronal firing
i.    Thalamo-cortical reverberating circuits: during absence type seizures, have reverberating circuits between cerebral cortex and thalamus at 3 Hz maintained by T-type Ca channels (since blocking these channels blocks the reverberating circuit)

Side effects: quite non-toxic; common= N/V and anorexia; less common = headache, sedation, photophobia

Benzodiazepines
All metabolites are active sedatives except the final glucuronide product. Elimination half-life varies a great deal from drug to drug.

?-Hydroxylation is a rapid route of metabolism that is unique to triazolam, midazolam, and alprazolam.
This accounts for the very rapid metabolism and short sedative actions of these drugs.

Pharmacological effects of benzodiazepines

- Antianxiety.
- Sedation.
- Anticonvulsant (including drug-induced convulsions).
- Amnesia, especially drugs like triazolam.
- Relax skeletal muscle (act on CNS polysynaptic pathways).

Indications

- IV sedation, (e.g., midazolam, diazepam, lorazepam).
- Antianxiety.
- Sleep induction.
- Anticonvulsant (e.g., diazepam, clonazepam).
- Panic disorders.
- Muscle relaxation.


Adverse effects

- Ataxia, confusion.
- Excessive sedation.
- Amnesia (not a desired effect with daytime sedation).
- Altered sleep patterns (increase stage 2 and decrease stage 4 sleep).

Megltinides

nateglinide
repaglinide

Mechanism

binds to K+ channels on β-cells → postprandial insulin release

Clinical use
type 2 diabetes mellitus
may be used as monotherapy, or in combination with metformin