Ketotifen

Structural formula
General
Non-proprietary name	Ketotifen
other names	4,9-dihydro-4- (methylpiperidin-4-ylidene) -10 H -benzo [4,5] cyclohepta [1,2- b ] thiophen-10-one
Molecular formula	C 19 H 19 NOS
External identifiers / databases
ECHA InfoCard	100,047,348
PubChem	3827
DrugBank	DB00920
Wikidata	Q2458673
Drug information
ATC code	R06 AX17
Drug class	Antihistamines
Mechanism of action	H 1 antihistamine
properties
Molar mass	309.43 g · mol -1
safety instructions
	Please note the exemption from the labeling requirement for drugs, medical devices, cosmetics, food and animal feed
GHS labeling of hazardous substances Caution
H and P phrases	H: 302
	P: no P-phrases
Toxicological data	585 mg kg −1 ( LD 50 , mouse , oral )
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Ketotifen is a drug from the group of H ₁ antihistamines . It also acts as a mast cell stabilizer . Areas of application are allergic diseases such as hay fever , atopic dermatitis and chronic urticaria . It can also be taken as a preventative against asthma attacks.

effect

Ketotifen is a reversible, competitive antagonist of the histamine H ₁ receptor (H ₁ antihistamine). It also acts as a leukotriene antagonist and inhibits the enzyme phosphodiesterase . The typical allergic complaints such as swelling of the eyelids, tearing, runny nose, itching and sneezing are reduced.

Application and pharmacokinetics

The drug can be taken orally in the form of tablets to prevent asthma attacks (no approval in Switzerland), or given as eye drops in the eyes for the treatment of allergic conjunctivitis . The active ingredient is almost completely absorbed in the gastrointestinal tract, but due to the high first-pass effect, the oral bioavailability is only 60%. 75% of the substance is bound to plasma proteins in the blood. In the local application z. B. in the eye, relevant blood levels cannot be assumed.

It is broken down by the liver, with the plasma half-life being approximately twelve hours.

Contraindications and side effects

As a 2nd generation antihistamine, ketotifen has fewer side effects such as: B. on the CNS than the older diphenhydramine . Via its anticholinergic effects, ketotifen can cause blurred vision with sensitivity to light due to mydriasis , dry mouth and tiredness. It should not be used in epilepsy, pregnancy and breastfeeding, or in children under three years of age.

Trade names

Many, including generics: Zabak, Zaditen

Individual evidence

↑ ^a ^b Data sheet Ketotifen fumarate salt from Sigma-Aldrich , accessed on February 20, 2017 ( PDF ).
↑ Data sheet Ketotifen Fumarate Salt from Spectrum Chemicals, accessed on February 20, 2017.
↑ L. Craps: Prophylaxis of asthma with ketotifen in children and adolescents: a review . In: Pharmatherapeutica . tape 3 , no. 5 , 1983, pp. 314-326 , PMID 6405397 .
^ G. Schwarzer, D. Bassler, A. Mitra, FM Ducharme, J. Forster: Ketotifen alone or as additional medication for long-term control of asthma and wheeze in children . In: The Cochrane Database of Systematic Reviews . No. 1 , 2004, p. CD001384 , doi : 10.1002 / 14651858.CD001384.pub2 , PMID 14973969 .
↑ Ketotifen drops: Indications, Side Effects, Warnings. In: Drugs.com. Retrieved February 20, 2017 .
↑ Ed. Harald Schmidt: Pharmacology and toxicology: for study and practice. 6th edition. Schauttauer, Stuttgart 2007. ISBN 978-3-7945-2295-8 , pp. 357f.

[Sigma-1] Data sheet Ketotifen fumarate salt from Sigma-Aldrich , accessed on February 20, 2017 ( PDF ).

[2] Data sheet Ketotifen Fumarate Salt from Spectrum Chemicals, accessed on February 20, 2017.

[3] L. Craps: Prophylaxis of asthma with ketotifen in children and adolescents: a review . In: Pharmatherapeutica . tape 3 , no. 5 , 1983, pp. 314-326 , PMID 6405397 .

[4] G. Schwarzer, D. Bassler, A. Mitra, FM Ducharme, J. Forster: Ketotifen alone or as additional medication for long-term control of asthma and wheeze in children . In: The Cochrane Database of Systematic Reviews . No. 1 , 2004, p. CD001384 , doi : 10.1002 / 14651858.CD001384.pub2 , PMID 14973969 .

[5] Ketotifen drops: Indications, Side Effects, Warnings. In: Drugs.com. Retrieved February 20, 2017 .

[6] Ed. Harald Schmidt: Pharmacology and toxicology: for study and practice. 6th edition. Schauttauer, Stuttgart 2007. ISBN 978-3-7945-2295-8 , pp. 357f.