Pharmaco Routes of Drug Admistration

8/17/2019 Pharmaco Routes of Drug Admistration

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FAR 142 Basic Pharmacology andBiochemistry

ROUTES OF DRUG AD!"!STRAT!O"

"AE # $O% &A' (U" )GROUP

A*

ATR!+ "UBER # 12,-2.

DATE # 1/T' APR!$ 2.10

$E+TURER # Dr AP U" FE!


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A!:

To compare the infuence o the route o administration on the onset and

duration o action in response to a hynoptic drug, sodium pentobarbitone

(40mg/kg), in mice.

E3!UPE"TS A"D ATER!A$S#

Pease kindy reer to the Pharmacoogy Practica !anua page "#

ET'OD#

Pease kindy reer to the Pharmacoogy Practica !anua pages "# $ "%

RESU$TS#

Rotes o5 administration o5 sodim 6ento7ar7itone6o sc im i6 i8

Body

9eight

)gm*

&'.0 &4.% &'.# &.# &.4

:olme o5

drg

soltion

)ml*

0.&' 0.& 0.&* 0. 0.4

Time o5

drg

administra

tion

)hor;min*

%.' a.m. "0.0# a.m. "0."4 a.m. "0.& a.m. "".0# a.m.

Time o5

loss o5

righting

re


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)hor;min*

Dration

o5 action)min*

"0 "4 ' % 40

D!S+USS!O"#

". The onset o drug action reers to the time it takes or the drug to

sho+ a therapeutic response. The duration o action can be dened

as the time a drug concentration is su-cient to eicit therapeuticresponse. t means the duration o time that the drug impose a

therapeutic response on the body, in this case, the mice.

&. ased on the resuts +e got rom the eperiment, the duration taken

or the onset o drug action o sodium pentobarbitone or di1erent

routes o administration is as oo+:Intravenous < Subcutaneous < Oral = Intraperitoneal <Intramuscular

. Theoreticay, the duration taken or the onset o drug action basedon di1erent routes o administration shoud be as oo+:Intravenous < Intraperitoneal < Intramuscular < Subcutaneous <Oral

4. n this eperiment, the dose to be gi2en to each mouse is cacuated

based on their +eight. This is because di1erent +eight +i a1ect the

distribution o drugs in the body.

. Parentera routes pro2ide shorter durations o action because they

don3t need to go through the rstpass metaboism but directydi1use into the bood capiaries and into the bood circuation to the

site o action. 5hereas ora administration +i go through rstpass

metaboism. The drug has to pass through gastrointestina tract

(6T), ony then to di1use into the bood circuation, so+ing its

onset o action. t +i be metaboi7ed by 6T and i2er en7ymes, so

this reduces amount o drug thatutimatey reaches the systemic

circuation.


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n the case o intramuscuar administration, the onset o action is

theoreticay pro2en to be so+er than intraperitonea but aster than

subcutaneous. The absorption o the drug is di1usioncontroed but it

is aster o the high 2ascuarity o the musce tissue. o+e2er, the

rate o absorption is a1ected by physioogica actors such as thebood circuation o the musce and the state o muscuar acti2ity. n

this eperiment, intramuscuar is ound to ha2e the so+est onset o

action. ?uring administration, the drug might be in@ected into the

area +hich is ess 2ascuari7ed, or the neede is not inserted deep

enough into the musce, resuting in the drug being administered ony

into the subcutaneous area, reducing its bioa2aiabiity. Thereore, its

duration o drug action is reati2ey o+. o+e2er, it +as situated the

second astest among the others. This may because the dose or

concentration o drug gi2en is Auite high or the mice.

ntraperitonea

due to it being metaboi7ed in the 6T and the i2er.

Thereore, it has the shortest duration o action theoreticay.

o+e2er, it is the second ongest among the others. This might


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caused by its p o gastrointestina tract +hich near to neutra or its

o+ gastric motiity.

;ubcutaneous

n this eperiment, the subcutaneous in@ection paced the secondhighest o onset o drug. ;ubcutaneous in@ection has a reati2ey o+

onset o action theoreticay due to its poor 2ascuari7ation in the

subcutaneous ayer compared to the rest o the parentera routes.

The rate o absorption is di-cut to contro rom the subcutaneous

deposits ike atty tissues. The rate o di1usion o drug is thereore

decreased. o+e2er, pentobarbita is highy ipid soube and at

content may ater the distributi2e Auaities o the drug. ;ome o the

drug +i be trapped in the ayer or a onger period o time. ;o the

onset o action is so+er. The de2iation o the resut rom eperiment

+ith the theory might cause by the reati2ey high concentration o

drug gi2en. o+e2er, due to its constant and proonged reease into

the bood circuation, the duration o action is reati2ey ong.

2. Explain why pentobarbitone and drugs of its kind are no more

used as anxiolytics and hypnotics.

= hypnotic drug is used primariy to induce seep, treat insomnia and

or anesthetic use +hie an anioytic drug is used or the treatmento aniety and its reated psychoogica and physica symptoms.

;odium pentobarbitone is a 2ery potent drug and its margin o saety

is 2ery narro+. The therapeutic inde is o+, thus o2erdose happens

2ery easiy. B2erdose may be ata or resut in a coma. Toerance

occurs upon proonged used, and this resuts in high iabiity o drug

abuse. Psychoogica and physica dependence may de2eop +ith

repeated use. = suddeny +ithdra+a o pentobarbitone +i cause

con2usion, coma and e2en death.

3. ist routes of drug administration other than those stated in

this experiment. !ive one example of drug administered via

each route given and the rationale for choosing the named

route.

a* nhaation: nhaation is used or rapid onset o drug action to act on

the ungs, as the drug ony takes ' $ "0 seconds to reach the brain. ts

unction is or systemic dei2ery o potent drugs ike genera


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anesthetics during surgery. t is aso administered or oca dei2ery o

drugs ike epinephrine or asthma reie.

7* Transderma route: This route is used or patients +ho are unabe to

take ora medication. The drug ike nicotine is disseminatedsystemicay through a patch on the skin. t is aso e1ecti2e or oca

action or drugs such as anagesics and antibiotic creams.

c) !ucousa route(i) ;ubingua route: = sma amount o drug administered beo+ the

tongue or rapid absorption o the drug into the sma bood

2esses +hich ie @ust beneath the tongue, +ithout rstpass

e1ect, mainy or the systemic dei2ery o potent drugs.

Cnitrogycerin is administered subinguay or angina reie.

(ii) Casa route: ?rug is transormed into tiny dropets in air

(atomi7ed), then breathed in and absorbed through the thin

mucous membrane that ines the nasa passages. Bnce absorbed,

the drug enters the boodstream. t is mainy or oca dei2ery o

drugs ike antihistamine or antiinfammatory

(ii) Bcuar route: t is used or oca dei2ery o drugs to treat eye

diseases ike pupi diation and cataracts. Darbacho is

administered ocuary to constrict the pupis during cataract

surgery(iii) 8agina route: t is used or oca dei2ery o drugs ike

prostagandin mainy to induce abour.(i2) 9ecta route: ?rug is usuay administered in the orm o a

suppository to the rectum or patients +ho ha2e di-cuties in

s+ao+ing medication or nausea. t is aso used or systemic

dei2ery o potent drugs because the rectumEs +a is thin and its

bood suppy rich, so the drug is readiy absorbedF or or oca

dei2ery o drugs ike anagesics or reie2e o pain due to

hemorrhoid.


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". Discuss the possibilities of administering sodium

pentobarbitone via intrarectal# inhalation and topical routes.

a) !ntrarectal: The amount o drug absorbed into the bood circuation is

not accuratey kno+n i it3s intrarectay administered because recta

doses are 2ery erratic +hen suppositoriesare disso2ed by the recta

fuid and di1use into the bood circuation. This may resut in an

underdose or o2erdose. ;o administration intrarectay is not ad2ised.

b) !nhalation: =dministration through inhaation is not appropriate as

the sodium pentobarbitone moecues are directed into the ungs

instead o the brain, +hich is the site o action. Thus the drug +i not

impose its e1ect, that is hypnotic and anioytic.

c) To6ical rotes: Topica administration ony produces ocai7ed e1ect.

;odium pentobarbitone is a +atersoube sat, and i appied to the

skin, +i not be abe to penetrate the hydrophobic skin ayer into the

body. The drug +i not be abe to reach the centra ner2ous system.

PRE+AUT!O"S#

". !ake sure that the oraeeding neede is inserted through the

oesophagus and ad2anced into the stomach. reathing di-cuties

indicate that the neede has been mistakeny inserted into thetrachea.

&. !ake sure there is no air bubbe in the syringe to pre2ent 2enous air

emboisms.. 6ente pressure is appied to the in@ection site ater parentera

administration to ensure that the drug is not eaking out.

+O"+$US!O"S#

1. Based on experiment, the duration taken for the onset of drug action for different

routes of administration of sodium pentobarbitone is as follows:

Intravenous < Subcutaneous < Oral = Intraperitoneal <

Intramuscular

2. Theoreticay, the duration taken or the onset o drug action based

on di1erent routes o administration shoud be as oo+s:Intravenous < Intraperitoneal < Intramuscular < Subcutaneous <

Oral

3. ased on the eperiment, the duration o drug action or di1erent

routes o administration o sodium pentobarbitone is as oo+s:


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Intravenous < Intramuscular < Intraperitoneal < Oral <

Subcutaneous

4. The onset o sodium pentobarbitone depends on the rate o

absorption o the drug into the bood circuation to its site o action

and its bioa2aiabiityF its distribution throughout the bodyF its rate

o being metaboised and ecreted.

5. Parentera routes pro2ide a Auicker e1ect to the body than ora

administration due to its high rate o absorption into the bood

circuation.

REFERE"+ES#

". http://+iki.ans+ers.com/H/5hyIisIpentobarbitoneIandIdrugsIoIitsI kindIareInoImoreIusedIasIanioyticsIandIhypnotics&. http://proessiona.cancerconsutants.com/[email protected]&'%&. http://+++.ncbi.nm.nih.go2/pubmed/"''&4'4. http://+++.merckmanuas.com/home/sec0&/ch0""/ch0""b.htm. Le+a L. Main (&00'). ?rug ?ei2ery ;ystem. umana Press.6. Pharmacoogy Practica !anua (&0"). ;choo o Pharmaceutica

;ciences, Nni2ersiti ;ains !aaysia.
http://wiki.answers.com/Q/Why_is_pentobarbitone_and_drugs_of_its_kind_are_no_more_used_as_anxiolytics_and_hypnoticshttp://wiki.answers.com/Q/Why_is_pentobarbitone_and_drugs_of_its_kind_are_no_more_used_as_anxiolytics_and_hypnoticshttp://professional.cancerconsultants.com/ccj_pain.aspx?id=23792http://www.ncbi.nlm.nih.gov/pubmed/15737247http://www.merckmanuals.com/home/sec02/ch011/ch011b.htmlhttp://professional.cancerconsultants.com/ccj_pain.aspx?id=23792http://www.ncbi.nlm.nih.gov/pubmed/15737247http://www.merckmanuals.com/home/sec02/ch011/ch011b.htmlhttp://wiki.answers.com/Q/Why_is_pentobarbitone_and_drugs_of_its_kind_are_no_more_used_as_anxiolytics_and_hypnoticshttp://wiki.answers.com/Q/Why_is_pentobarbitone_and_drugs_of_its_kind_are_no_more_used_as_anxiolytics_and_hypnotics

Pharmaco Routes of Drug Admistration

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