laboratory work for drug administration in pharmacology class. Diponegoro University, School of Medicine

1. Drug Administration
Laboratory of Pharmacology
Department of Pharmacology and Therapeutics
Faculty of Medicine Diponegoro University
2012

2. • Enteral (oral? Intubation=
nasogastric tube?)
• Parenteral (Injection=
Intramuscular/Intravenous
/Intraperitoneal/Subcutan)
• Inhalation
Ovid: Lippincott's Illustrated Reviews: Pharmacology
• Topical

3. Drug Administration
• oral
• sublingual
• Rectal/rectal suppository
• application to other epithelial surfaces (e.g.
skin, cornea, vagina and nasal mucosa) topical-vaginal
suppository
• inhalation
• Injection
– Subcutaneous
– Intramuscular
– Intravenous
– Intrathecal
– intravitreal.

5. Enteral Administration

6. 0
Phenobarbital 1s
Drugsused in the prophylaxisof epileptic seizures
• Barbiturate drug, trade name
O H
Luminal O C 3
H
H N
N C CH • MainlyC Anticonvulsant
as C H5
2
2 5 O C O C
O C • Hypnotic effect, Sedative effect,
C
N N
N C • Bioavailability after proper
H H O
H administration = 95%
O
• Metabolism= Hepatic
Phenobarbital (Cytochrome P450) E
P henytoin thosuximide
• Half-life= 53-118 hours
C 2
H
• Excretion= Renal and Fecal
HC
C 2
H NH2 H2C NH2
HC NH2
C 2
H
C C 2
H

7. Clinical Use
• Phenobarbital is useful in the treatment of
partial seizures and generalized tonic-clonic
seizures, although the drug is often tried for
virtually every seizure type, especially when
attacks are difficult to control
• Depresses neurons activities via Reticular
Formation, Induces sleep
(Sedative, Hypnotics, and Anesthetics)

8. Formantio
Reticularis

9. GABA-mediated chloride ion channel
from Zorumski CF, Isenberg KE: Insights into the structure and function of GABA receptors: Ion
channels and psychiatry. Am J Psychiatry 1991;148:162.)

10. Pharmacokinetics
• The rates of oral absorption of sedative-
hypnotics differ depending on a number of
factors, including lipophilicity.
• Most of the barbiturates and other older
sedative-hypnotics, as well as the newer
hypnotics
(eszopiclone, zaleplon, zolpidem), are
absorbed rapidly into the blood following oral
administration.

11. Pharmacodynamics
• Benzodiazepines and phenobarbital augment
the activation of the GABAA receptor by
physiologically released amounts of GABA.
• Elongates the GABA-mediated Chloride Ion
Channel Opening.
• Elongates GABA and Glycine Inhibitory Effect
• Chloride influx is increased, counteracting
depolarization.
• Depresses the CNS via Reticular Formation.
• Induces sleep (Sedative, Hypnotics, and
Anesthetics)