Chlorphenamine

Structural formula
General
Non-proprietary name	Chlorphenamine
other names	Chlorpheniramine 3- (4-chlorophenyl) - N , N -dimethyl-3- (2-pyridyl) propylamine ( IUPAC )
Molecular formula	C 16 H 19 ClN 2
External identifiers / databases
CAS number 132-22-9 (chlorophenamine) 113-92-8 (chlorphenamine maleate) PubChem 2725 DrugBank DB01114 Wikidata Q420133
Drug information
ATC code	R06 AB04
Drug class	Antihistamine
properties
Molar mass	274.79 g mol −1
Physical state	firmly
Melting point	130–135 ° C (chlorophenamine maleate)
boiling point	142 ° C (0.13 kPa) (chlorophenamine)
safety instructions
Please note the exemption from the labeling requirement for drugs, medical devices, cosmetics, food and animal feed GHS labeling of hazardous substances danger H and P phrases H: 301 P: 301 + 310
Toxicological data	118 mg kg −1 ( LD 50 ,  rat ,  oral , chlorophenamine)
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Chlorphenamine (also chlorpheniramine ) is a first generation antihistamine that chemically belongs to the group of alkylamines . The maleate salt (chlorphenamine maleate ) is used as a drug . It is also used in veterinary medicine .

Effects

Chlorphenamine acts as an antagonist at the H ₁ receptor , which means that it counteracts allergic symptoms such as reddening of the skin, itching, conjunctivitis and rhinitis .

Chlorphenamine also inhibits the reuptake of serotonin and norepinephrine in nerve endings ( serotonin-norepinephrine reuptake inhibitors ), which gives it an antidepressant effect , although no studies on this use in humans exist. However, since the affinity for SERT with a dissociation K _i of 31 nM corresponds approximately to the affinity of imipramine and is thus 30 times weaker than citalopram , therapeutic, i.e. H. antihistamine doses (<10 mg) no antidepressant effects or side effects due to SERT inhibition are to be expected.

The main undesirable effect is a sedating effect , which affects the ability to drive. Overdosing can lead to anticholinergic syndrome with facial flushing, agitation, hallucinations, dry mouth, fever and cramps. Furthermore, under special conditions, a proarrhythmogenic potency ( torsades-des-pointes - tachycardias ) must be assumed.

In addition, the results of a prospective cohort study carried out by the University of Washington with around 3,500 participants from 2015 suggest that frequent or long-term use of chlorphenamine-containing drugs in doses of as little as 4 mg per day with a significantly increased risk of Dementia, such as Alzheimer's , is linked.

Since chlorphenamine probably also causes more side effects in elderly patients than the other two antiallergic drugs cetirizine and loratadine , this active ingredient was placed on the "PRISCUS list of potentially inadequate medications for the elderly" by the German research association "PRISCUS" and should therefore be used in elderly people if possible not be applied.

Pharmacokinetics

The bioavailability is below 50%, the plasma protein binding is about 70%, the duration of action three to six hours. The breakdown occurs mainly in the liver through hydroxylation and conjugation . The volume of distribution is relatively high at three to seven liters per kilogram of body weight. The plasma half-life is 15–30 hours, shorter in children.

Trade names

Balkis Snuff Capsules New (D); Trimeton (I)

Combination preparations: Benical (CH), Fluimucil Grippe (CH), Grippostad C (D, A), Migraine-Kranit (CH), Pecto-Baby (CH), Rhinipront (CH), Solmucalm (CH), Triocaps (CH)

Web links

• Entry on chlorphenamine at Vetpharm, accessed on August 5, 2012.

Individual evidence

1. ↑ ^{a b c} Entry on chlorphenamine. In: Römpp Online . Georg Thieme Verlag, accessed on June 1, 2014.
2. ↑ ^{a b} data sheet (±) -Chlorpheniramine maleate salt from Sigma-Aldrich , accessed on March 22, 2011 ( PDF ).
3. ^ A. Carlsson, M. Lindqvist: Central and peripheral monoaminergic membrane-pump blockade by some addictive analgesics and antihistamines. In: J Pharm Pharmacol . 21 (7), Jul 1969, pp. 460-464. PMID 4390069
4. ↑ M. Bodmer et al: Dextromethorphan, chlorphenamine and serotonin toxicity: case report and systematic literature review. In: Br J Clin Pharmacol . 70 (6), Dec 2010, pp. 794-798. PMID 21175434
5. ↑ AM Nia et al .: Torsades de pointes tachycardia induced by common cold compound medication containing chlorpheniramine. In: Eur J Clin Pharmacol . 66 (11), Nov 2010, pp. 1173-1175. Epub 2010 Jul 31
6. ^ Higher dementia risk linked to more use of common drugs - School of Pharmacy. In: School of Pharmacy. Retrieved April 9, 2016 (American English). 
7. ^ SL Gray, ML Anderson, S. Dublin et al.: Cumulative use of strong anticholinergics and incident dementia: A prospective cohort study . In: JAMA Internal Medicine . tape 175 , no. 3 , March 1, 2015, p. 401-407 , doi : 10.1001 / jamainternmed.2014.7663 , PMID 25621434 , PMC 4358759 (free full text).
8. ↑ Sleep and Allergy Meds Linked to Dementia, Alzheimer's. In: AARP. Retrieved April 9, 2016 . 
9. ^ Health in old age 2007 - Priscus_Liste. In: priscus.net. Retrieved April 9, 2016 . 
10. ↑ Red List Online, as of August 2009.
11. ↑ AM comp. d. Switzerland, as of August 2009.
12. ↑ AGES-PharmMed, as of August 2009.

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !