CHLORCYCLIZINE Synthesis, SAR, MCQ,Structure,Chemical Properties and Therapeutic Uses

huzefakifayet — Thu, 22 Oct 2020 04:56:04 +0000

Chlorcyclizine

IUPAC nomenclature

1-[(4-Chlorophenyl)(phenyl)methyl]-4-methylpiperazine

Classification

H1-receptor antihistamine
Piperazine antihistamine

Physiochemical Properties

S. NO.	PHYSICAL AND CHEMICAL PROPERTIES
1	Molecular weight	300.8g/mol
2	Physical appearance	Oil
3	Melting point	216^oC
4	Solubility	Water solubility is 0.0424 mg/ml
5	Octanol/water partition coefficient	3.45
5	Presence of ring	Piperazine , phenyl
6	Number of chiral centers	1

Mechanism of Action

Antihistamines such as chlorcyclizine acts as pharmacological antagonists of hitamine at the histamine receptor sites. They do not prevent the release of histamine.

There is also hepatic microsomal enzyme-inducing properties of chlorcyclizine which results in shortening of duration of action of some barbiturates as result of enzyme induction.

Structure Activity Relationship

Structure activity of piperizine antihistamines can be summarized as:

These are the derivatives of ethylene diamines.
The connecting moiety is CHN group
Primary structural difference is nature of para aromatic ring substituent
These are moderately potent.
Slow onset of action
Low incidence of drowsiness
They also exhibit peripheral and central antimuscarinic activity.

Method of synthesis

Alkylation of 1-methylpiperazine with 4-chlorobenzhydrylbromide gives chlorcyclizine. [1]

Medicinal Uses

Chlorcyclizine has:

Mildly sedative properties
Antihistaminic properties
Slight anticholinergic properties
Antispasmodic properties
It enhances the action of epinephrine
Local anesthetic action

Side Effects

Side effects of chlorcyclizine are:

Sedation
Dizziness
Tinnitus
Lassitude
Loss of coordination
Fatigue
Blurred vision
Diplopia
Euphoria
Nervousness
Insomnia
Tremors

MCQs

Q.1 Mechanism of action of chlorcyclizine drug includes?

a) Release of histamine in prevented

b) Release of histamine is stimulated

c) Antagonistic effects at H1 receptor for histamine

d) Agonist effects H1 receptor for Histamine

Q.2 Therapeutic use of drug Chlorcyclizine is/are?

a) Local anesthetic

b) Sedative

c) Antihistamine

d) All of the above

Q.3 The type of ring present in the structure of chlorcyclizine?

a) Piperazine

b) Pyridine

c) Cyclohexane

d) All of the above

Q.4 Number of chiral carbons present in the structure of Chlorcyclizine?

a) 0

b) 1

c) 2

d) 3

Q.5 Correct sequence for the True/False for the physiochemical properties of the drug Chlorcyclizine can be?

Molecular weight: 300.8 gm/mol
Physical appearance: Oil
Octanol/water partition coefficient: 3.45

a) TTT

b) TFT

c) FFT

d) TFF

Q.6 Correct statements for the IUPAC nomenclatures of the drugs are?

I. Chlorcyclizine: 1-[(4-Chlorophenyl)(phenyl)methyl]-4-methylpiperazine

II. Carbinoxamine: 2-[(4-Chlorophenyl)-pyridin-2-yl-methoxy]-N,N-dimethyl-ethanamine

III. Edrophonium: Ethyl-(3-hydroxyphenyl)-dimethylazanium

IV. Tenoxicam: 4-hydroxy-2-methyl-1,1-dioxo-N-pyridin-2-ylthieno[2,3-e]thiazine-3-carboxamide

a) I, II

b) III, IV

c) IV

d) I, II, III, IV

Q.7 Match the following drugs with their correct classifications-

i. Chlorcyclizine	A. H2-antagonist
ii. Cimetidine	B.Vasodilator
iii. Mercaptopurine	C. Antimetabolite
iv. Nitroglycerine	D. H1-receptor antihistamine