HOE 140

Absorption

The absolute bioavailability of icatibant following a 30 mg subcutaneous dose is approximately 97%. Maximum plasma concentrations (Cmax) of 974 ± 280 ng/mL was reached when a single subcutaneous dose of 30 mg was administered. The AUC was 2165 ± 568 ng?hr/mL. Icatibant did not accumulate following multiple doses.

Description

Hoe 140 (D-Arg-[Hyp3, Thi5, D-Tic7, Oic8]-bradykinin), on bradykinin- and platelet-activating factor (PAF)-induced bronchoconstriction and airway microvascular leakage in anesthetized guinea pigs. Hoe 140 is highly potent and long-acting in inhibiting BK-induced hypotensive responses in the rat. Four hours after s.c. administration of 20nmol kg-1, inhibition still amounted to 60% whereas the effect of 200nmol kg-1 of d-Arg-[Hyp2, Thi5,8, d-Phe7]BK was not significant[1-2].

The Uses of HOE 140

Antagonist (bradykinin).

Indications

Approved for use in acute attacks of hereditary angioedema (HAE). Investigated for use/treatment in angioedema, liver disease, and burns and burn infections.

Background

Icatibant (Firazyr) is a synthetic peptidomimetic drug consisting of ten amino acids, and acts as an effective and specific antagonist of bradykinin B2 receptors. It has been approved in the EU for use in hereditary angioedema, and is under investigation for a number of other conditions in which bradykinin is thought to play a significant role. Icatibant currently has orphan drug status in the United States and FDA approved on August 25, 2011.

Definition

ChEBI: A ten-membered synthetic oligopeptide consisting of D-Arg, Arg, Pro, Hyp, Gly, Thi, Ser, D-Tic, Oic, and Arg residues joined in sequrence. A bradykinin receptor antagonist used as its acetate salt for the treatment of acut attacks of hereditary angioedema in adult patients.

brand name

Metastat (CollaGenex).

Pharmacokinetics

Icatibant is a potent, specific, competitive, and selective peptidomimetic bradykinin beta2-receptor antagonist (pA2 = 9.04). It has a modified peptide structure, and is the first bradykinin receptor antagonist to act on the guinea-pig trachea without demonstrating agonist effects. It also inhibits aminopeptidase N (Ki = 9.1 μM). If an IV dose of 0.4 and 0.8 mg/kg was infused over 4 hours, one may observe an inhibited response to bradykinin challenge for 6 - 8 hours following completion of infusion.

Metabolism

Icatibant is metabolized by proteolytic enzymes into inactive metabolites. The cytochrome P450 enzyme system is not involved with the metabolism of icatibant.

storage

Store at -20°C

References

[1] K. Wirth. “Hoe 140 a new potent and long acting bradykinin-antagonist: in vivo studies.” British Journal of Pharmacology 102 3 (1991): 774–777.
[2] T Sakamoto. “Effect of Hoe 140, a new bradykinin receptor antagonist, on bradykinin- and platelet-activating factor-induced bronchoconstriction and airway microvascular leakage in guinea pig.” European journal of pharmacology 213 3 (1992): 367–73.