pharmaco - chapter 6 Flashcards
type of cholinomimetic drug
• Inhibiting the hydrolysis of endogenous Ach
Indirect-acting
type of cholinomimetic drug
• Binding/activate cholinoceptors
Direct-acting
4 impt choline esters
acetycholine
carbachol
betanechol
methacholine
type of direct-acting drug
- Permanently charged quaternary NH4 group
choline ester
type of direct-acting drug
- Relatively insoluble in lipids
- Poorly absorbed
choline ester
type of direct-acting drug
-Hydrolyzed in the GIT
choline ester
type of direct-acting
Hydrophilic
choline ester
type of direct-acting drug
Poorly distributed in the CNS
choline ester
type of choline ester
- Addition of methyl CH3
- 3x more resistant to hydrolysis compared to Ach
METHACHOLINE
TYPE OF DIRECT-ACTING DRUG
- Act mostly with muscarinic receptors
(muscarine, pilocarpine)
- Act with nicotinic receptors(nicotine, lobeline)
ALKALOIDS
4 impt alkaloids
nicotine
pilocarpine
lobeline
muscarine
type of alkaloid
- Liquid
- Sufficiently lipid-soluble to be absorbed across
the skin
NICOTINE
type of alkaloid
- Quaternary amine
- Less completely absorbed from the GIT
- Toxic when ingested
- Eg, in certain mushrooms, it even enters the brain
muscarine
type of alkaloid
- Plant derivative
- Similar to nicotine
LOBELINE
type of Ach
– methyl group at α carbon was changed to amino group
c. Carbachol
type of Ach
– addition of methyl group at β carbon, replacement of methyl group with amino group at α carbon
Betanechol
type of Ach
addition of methyl group at the β carbon
methacholine
type of NH4 group
- no more electrons to share, cannot attach
- becomes insoluble in lipids
quaternary
type of NH4 group
-cannot be given orally because it has a short duration of action (easily hydrolyzed because water- loving)
quaternary
type of NH4 group
-no penetrability of CNS because easily hydrolyzed in GIT, cannot reach CNS
quaternary
unlike choline esters, they don’t have parent drugs because most of them are derived from plants
- Alkaloids –
type of direct-acting drug
- longer duration of action
- can be given through the oral route
- not easily hydrolyzed by GIT
alkaloids
type of alkaloid – cigarette -isolated as a liquid -easily absorbed across the skin -risk is the same for active and passive smoker
nicotine
type of alkaloid
isolated from mushrooms
Muscarine
-if there is mushroom poisoning, the signs and symptoms would be
parasympathetic (diarrhea, sweating, increase in salivation, increase in urination)
ciliary muscle contraction would allow ___ of aqueous humor
outflow
what happens if aqueous humor accumulates
intraocular pressure increases - glaucoma
type of drug to give to someone with glaucoma
pilocarpine
Parasympathetic antagonist – will ____ the lungs
dilate
can you give parasympathetic antagonist to asthmatic patients
yes
when there is no activity in the intestine, give a type of drug
parasympathetic drug
-predominant receptor in BV
α1
Are there are receptors for parasympathetic in the blood vessels
no
In BV, -under parasympathetic influence, it stimulates the secretion of _________, which cause vasodilation, thus blood pressure would decrease
EDRF or nitrous oxide
does parasympathetic have a direct influence on blood vessels?
nO
Relaxed muscle of the bladder – urine WOULD GO WHERE
accumulates inside
Contraction of bladder – urine WOULD GO WHERE
urine goes out
To make bladder contract, give what type of drug
parasym
type of indirect acting
- has quaternary NH4 group
- prototype drug: Edrophonium
simple alcohol
-prototype drug of simple alcohol
Edrophonium
predom stimulation in CVS
more of sympathetic influence
What does EDRF or NO do
vasodilation, thus blood pressure would decrease
type of indirect acting
- can be given orally
- neostigmine
- physostigmine (exception, lipid soluble)
- Carbamates
type of indirect acting
Quaternary or tertiary NH4 group
30 minutes to 6 hours
Reversible
- Carbamates
exception in carbamates because it is lipid soluble
physostigmine
type of indirect acting
Highly lipid soluble
Very long duration
Irreversible
ORGANIC DERIVATIVES OF PHOSPHORIC
ACID
type of organophosphate
Used as insecticides
Parathion and malathion (thiophosphates)
