Clinical data
Trade namesTalis
ATC code
  • none
  • 7-bromo-5-(2-chlorophenyl)-2-(methoxymethyl)-1-methyl-2,3-dihydro-1,4-benzodiazepine
CAS Number
PubChem CID
CompTox Dashboard (EPA)
Chemical and physical data
Molar mass393.71 g·mol−1
3D model (JSmol)
  • ClC1=CC=CC=C1C2=NCC(COC)N(C)C3=C2C=C(Br)C=C3
  • InChI=1S/C18H18BrClN2O/c1-22-13(11-23-2)10-21-18(14-5-3-4-6-16(14)20)15-9-12(19)7-8-17(15)22/h3-9,13H,10-11H2,1-2H3 checkY

Metaclazepam[1] (marketed under the brand name Talis) is a drug which is a benzodiazepine derivative.[2][3] It is a relatively selective anxiolytic with less sedative or muscle relaxant properties than other benzodiazepines such as diazepam or bromazepam.[4] It has an active metabolite N-desmethylmetaclazepam, which is the main metabolite of metaclazepam.[5] There is no significant difference in metabolism between younger and older individuals.[6]

Metaclazepam is slightly more effective as an anxiolytic than bromazepam,[7] or diazepam,[8] with a 15 mg dose of metaclazepam equivalent to 4 mg of bromazepam.[9] Metaclazepam can interact with alcohol producing additive sedative-hypnotic effects.[6][10] Fatigue is a common side effect from metaclazepam at high doses.[11] Small amounts of metaclazepam as well as its metabolites enter into human breast milk.[12]

See also


  1. ^ US 4098786 
  2. ^ Borchers F, Achtert G, Hausleiter HJ, Zeugner H (1984). "Metabolism and pharmacokinetics of metaclazepam (Talis), Part III: Determination of the chemical structure of metabolites in dogs, rabbits and men". European Journal of Drug Metabolism and Pharmacokinetics. 9 (4): 325–46. doi:10.1007/bf03189684. PMID 6532806. S2CID 12290664.
  3. ^ Althaus W, Block J, Förster A, Kühnhold M, Meister D, Wischniewski M (September 1986). "Analytical profile of metaclazepam". Arzneimittel-Forschung. 36 (9): 1302–6. PMID 3790179.
  4. ^ Buschmann G, Kühl UG, Rohte O (1985). "General pharmacology of the anxiolytic compound metaclazepam in comparison to other benzodiazepines". Arzneimittel-Forschung. 35 (11): 1643–55. PMID 2868732.
  5. ^ Gielsdorf W, Molz KH, Hausleiter HJ, Achtert G, Philipp P (1986). "Pharmacokinetic profile of metaclazepam (Talis), a new 1.4-benzodiazepine. Influence of different dosage regimens on the pharmacokinetic profile of metaclazepam and its main metabolite under steady-state conditions". European Journal of Drug Metabolism and Pharmacokinetics. 11 (3): 205–10. doi:10.1007/bf03189848. PMID 3816876. S2CID 8493668.
  6. ^ a b Molz KH, Gielsdorf W, Rasper J, Jaeger H, Hausleiter HJ, Achtert G, Philipp P (1985). "Comparison of the pharmacokinetic profile of metaclazepam in old and young volunteers". European Journal of Clinical Pharmacology. 29 (2): 247–9. doi:10.1007/bf00547431. PMID 4076323. S2CID 8017809.
  7. ^ Bilone F, Roncari R (1988). "A double-blind comparison of the anxiolytic activity of two benzodiazepines, metaclazepam and bromazepam, in anxiety neurosis". Current Medical Research and Opinion. 11 (1): 45–7. doi:10.1185/03007998809111130. PMID 2898321.
  8. ^ Laakmann G, Blaschke D, Hippius H, Schewe S (May 1989). "Double-blind study of metaclazepam versus diazepam treatment of outpatients with anxiety syndrome". Pharmacopsychiatry. 22 (3): 120–5. doi:10.1055/s-2007-1014593. PMID 2568645.
  9. ^ Marano P, Patti F, Nicoletti F (1988). "Controlled study on the anxiolytic activity of a newly-developed benzodiazepine, metaclazepam". Current Medical Research and Opinion. 11 (1): 41–4. doi:10.1185/03007998809111129. PMID 2898320.
  10. ^ Schmidt V (1983). "[Experimental studies on the interaction of alcohol and metaclazepam]". Beiträge zur Gerichtlichen Medizin. 41: 413–7. PMID 6639614.
  11. ^ Laakmann G, Blaschke D, Hippius H, Schewe S (May 1988). "Double-blind randomized trial of the benzodiazepine derivative metaclazepam as compared with placebo treatment of outpatients with anxiety syndromes". Pharmacopsychiatry. 21 (3): 136–43. doi:10.1055/s-2007-1014665. PMID 2900514.
  12. ^ Schotter A, Müller R, Günther C, Hausleiter HJ, Achtert G (November 1989). "Transfer of metaclazepam and its metabolites into breast milk". Arzneimittel-Forschung. 39 (11): 1468–70. PMID 2575907.