Flurazepam

Structural formula
General
Non-proprietary name	Flurazepam
other names	7-chloro-1- (2-diethylaminoethyl) -5- (2-fluorophenyl) -1,3-dihydro-2 H -1,4-benzodiazepin-2-one ( IUPAC ); Flurazepamum ( Latin );
Molecular formula	C 21 H 23 ClFN 3 O
Brief description	white sticks or crystals
External identifiers / databases
ECHA InfoCard	100,037,795
PubChem	3393
DrugBank	DB00690
Wikidata	Q418998
Drug information
ATC code	N05 CD01
Drug class	Benzodiazepines , hypnotics
properties
Molar mass	387.88 g · mol -1
Melting point	79.5 ° C ; 214.5-217.5 ° C (dihydrochloride);; 202–203 ° C (hydrochloride);
pK s value	pK s1 : 1.57 and 1.90, respectively; pK s2 : 8.16 and 8.37, respectively
solubility	very easily soluble in water; easily soluble in ethanol ; practically insoluble in diethyl ether
safety instructions
	Please note the exemption from the labeling requirement for drugs, medical devices, cosmetics, food and animal feed
H and P phrases	H: 302-373
	P: no P-phrases
Toxicological data	980 mg kg −1 ( LD 50 , rat , oral ) ; 879 mg kg −1 ( LD 50 , rat , oral , dihydrochloride) ;
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

The flurazepam is one of the long-acting benzodiazepines . It is used for the short-term treatment of problems falling asleep and through sleep disorders. With long-term use there is a risk of harmful use .

Pharmacokinetics

The oral bioavailability of flurazepam is very good; almost complete absorption takes place. Flurazepam is a prodrug . The substance is rapidly converted to the pharmacologically active metabolites hydroxyethylflurazepam and flurazepamaldehyde and somewhat less rapidly to desalkylflurazepam, the metabolism probably being catalyzed by the cytochrome P450 subgroups CYP3A4 and CYP2C19 . In contrast to the other two metabolites, desalkylflurazepam accumulates, the plasma half-life of which is between 50 and 100 hours. If flurazepam is taken several times, desalkylflurazepam achieves constant concentrations in the blood plasma after several days. The maximum plasma concentration of flurazepam is reached after 1 to 3 hours, that of its metabolites, depending on which, after 0.5 to 96 hours.

Mechanism of action

Flurazepam strengthens the effect of the body's own neurotransmitter GABA in the central nervous system . This is done by binding the flurazepam to the GABA receptor .

The effect of the flurazepam wears off if it is taken for more than 14 days. This is due to the regulating mechanism in which the body tries to restore its original homeostasis , its steady state. To keep the effect constant, the dose would have to be increased steadily, which would lead to dependence.

Side effects

Long-term use and higher doses often lead to drowsiness, dizziness, confusion and memory disorders, which also lead to a prolonged reaction time .

During the use of Flurazepam, it can also lead to movement and gait insecurity due to the slackening effect on the muscles .

Use during pregnancy and breastfeeding

There is clear evidence of risks to the human fetus if ingested during pregnancy, but the therapeutic benefits to the mother may outweigh this. Flurazepam is excreted in breast milk. If regular intake is necessary, weaning is recommended.

Trade names

Monopreparations

Dalmadorm (D, CH), Staurodorm (D), Flurazepam Real (D)

Individual evidence

↑ ^a ^b ^c ^d ^e Entry on Flurazepam. In: Römpp Online . Georg Thieme Verlag, accessed on July 2, 2019.
↑ ^a ^b Entry on flurazepam in the ChemIDplus database of the United States National Library of Medicine (NLM) .
↑ Sean Sweetman (Editor): Martindale: The Complete Drug Reference, 35th Edition: Book and CD-ROM Package . Pharmaceutical Press, ISBN 978-0-85369-704-6 .
↑ ^a ^b Data sheet for Flurazepam dihydrochloride from Sigma-Aldrich , accessed on April 2, 2011 ( PDF ).
^ Benkert & Hippius: Compendium of Psychiatric Pharmacotherapy , 8th edition, Springer, 2011. ISBN 978-3-642-13043-4 .
^ Specialist information from the Swiss Medicines Compendium: Dalmadorm®, as of November 1995.

[roempp-1] Entry on Flurazepam. In: Römpp Online . Georg Thieme Verlag, accessed on July 2, 2019.

[ChemIDplus-2] Entry on flurazepam in the ChemIDplus database of the United States National Library of Medicine (NLM) .

[Martindale-3] Sean Sweetman (Editor): Martindale: The Complete Drug Reference, 35th Edition: Book and CD-ROM Package . Pharmaceutical Press, ISBN 978-0-85369-704-6 .

[sigma-4] Data sheet for Flurazepam dihydrochloride from Sigma-Aldrich , accessed on April 2, 2011 ( PDF ).

[B&H-5] Benkert & Hippius: Compendium of Psychiatric Pharmacotherapy , 8th edition, Springer, 2011. ISBN 978-3-642-13043-4 .

[6] Specialist information from the Swiss Medicines Compendium: Dalmadorm®, as of November 1995.