For our class in Pharmacology, we had an experiment on the onset and duration of drugs administered on a subject, who are in this case, poor rabbits.
The big group which I belong to was divided into five more subgroups, representing five different routes of administration, which are the Oral, Intravenous, Intramuscular, Intraperitoneal and Subcutaneous Routes.
Doctor assigned me to be part of the Subcutaneous group.
Prep:
All groups may chose any of the rabbits caged in the laboratory, only one rabbit per group. Kat, my co-member and I agreed on a rabbit which has pearl-white fur and red eyes. It is an albino, and it sooo cute. I personally picked it and laid it on our basket...she was a female, and a fragile one. Though the rabbit seemed harmless, holding it was kind of scary, for the rabbits were fasted for 12 hours prior to the experiment (so that all the rabbits will be equal in terms of pharmacokinetics) so that pharmacodynamics will not be affected. We weighed our rabbit, and she weighs 337.3 grams.
Drug:
For the drug to be used, all of the groups were instructed to use 2.0% Thiopental Sodium Solution which is a barbiturate, a sedative.
Calculation of drug dosage:
weight of the rabbit x concentration of drug = dose of drug
337.3 g x 2.0% or 0.02 mg/g = 6.746 mg
6.74 mg converted to ml is 0.3373 ml
Drug Administration:
The drug was injected on the back of the rabbit, in the interscapular area. The needle was inserted perpendicularly in relation to the surface of the skin fold, to such a depth that the point of the needle lied between the two opposing skin surfaces. However, while expelling the contents of the syringe, the point of the needle went through the opposing skin and a significant amount of drug was spilled outside of the rabbit's body. The rabbits' fur was so thick that the group didn't actually notice it until the liquid was felt by the member who was holding the rabbit. Due to this, we requested for another helping of the drug, but this time, we estimated the amount to give (the group's decision was not to report what happened. hahaha.) In addition to the first injection, we injected another 0.25ml to the rabbit.
Observation:
 |
Our poor albino fur ball, fighting hard not to doze off.
[my personal observation notes on that time were as follows]
1: 48 PM : drug administration
**scratches part of her body that was injected
1: 53: eyes are beginning to close
1: 58: Righting Reflex still intact
**RF- the ability of the animal to assume upright position when placed in supine position
2: 03: still awake but drowsy, LOST RF
**considered as onset of the drug |
2: 08: getting more drowsy
2: 13: defecated, became a little active
2: 18: became more active, chewed on the Manila paper,
Definitely hungry. wawa naman.:(
2: 23: back to being active
Results:
Drug Onset: 15 mins. after drug administration
Duration of Effect: 10 mins.