Diabetes in Pets
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Insulin hex di mon

Insulin hexamers (as produced by the body or injected) must break down into dimers and monomers to be absorbed[1].

Apidra is a brand name for insulin glulisine, a fast-acting human analog[2] manufactured by Aventis. It is a soluble insulin and can be used intravenously for diabetic emergencies such as DKA. Apidra has been found to be equipotent (equally potent) to R/neutral R-DNA/GE/GM insulin when administered intravenously.

Given subcutaneously in normal injection form, Apidra has a more rapid onset and shorter duration than R human insulin[3].

Technical details[]

The alterations to the human insulin molecule that produces insulin Glulisine are all to the B insulin chain; position B-#3, which is normally amino acid asparagine is replaced with lysine and the lysine amino acid which is normally found at position B-#29 is replaced by glutamic acid[4]. Making substitutions at these positions on the B insulin chain, inhibits hexamer formation[5].

Since insulin in hexamer form must break down into dimers and monomers to become active, inhibiting the molecule's natural tendency to form hexamers by self-association, means better, faster absorption, more rapid onset, peak and shorter duration. Apidra[6] may be diluted for all uses except in insulin pumps. It may be mixed in the same syringe with NPH/isophane insulin only.

http://products.sanofi-aventis.us/apidra/images/apidra_chem.gif
Alterations to human insulin producing insulin glulisine (Apidra).

There is no clinical data regarding same syringe mixing of Apidra and any other insulin preparations in humans, but testing conducted in dogs indicates a slower onset when mixed with NPH/isophane insulin. Used on its own, Apidra displayed an earlier onset with them[7]. Antibody formation in the dog was noted.

Dr. Nelson of University of California-Davis said in his lecture at the Ohio State Endocrinology Symposium in 2006 that if the short-acting analog insulins have any role in feline and canine diabetes, it is not yet determined[8].

Insulin amino acid sequences[]


Amino Acid Sequence of Insulin Preparations[9]
Amino Acid Substitutions

 

  A-Chain Position  

B-Chain Position

Source
Species
A-8 A-10 A-21 B-28 B-29 B-30 B-31
B-32
Beef Ala Val Asn Pro Lys Ala N/A
Pork Thr Ilc Asn Pro Lys Ala N/A
Human Thr Ilc Asn Pro Lys Thr N/A
Aspart Thr Ilc Asn Aspartic Acid Lys Thr N/A
Lispro Thr Ilc Asn Lys Pro Thr N/A
Glulisine Thr Ilc Asn Pro Glu Thr N/A
Lantus (glargine) Thr Ilc Gly Pro Lys Thr Arg
Levemir(detemir) Thr Ilc Asn Pro Lys N/A Myristic Acid
Ala=Alanine Val=Valine Asn=Asparagine Pro-Proline Lys=Lysine Thr=Threonine Ilc=Isoleucine Glu-Glutamine Gly=Glycine



Insulin pharmacokinetics[]

Pharmacokinetics of Insulin Preparations[10]
Insulin Preparations
Onset (hr)
Peak (hr)
Duration (hr)
Rapid-Acting
R/Neutral
0.5 to 1
2.5 to 5
8 to 12
Lispro
0.25 to 0.5
0.5 to 1.5
2 to 5
Aspart
0.17 to 0.33
1 to 3
3 to 5
Glulisine
0.17 to 0.33
1 to 3
3 to 5
Intermediate-Acting
NPH
Isophane
1 to 1.5
6 to 14
16 to 24
Lente[11]
1 to 3
6 to 14
20+
70/30-30/70
0.5 to 1
2 to 12
24
50/50
0.5 to 1
2 to 12
24
Novolog 70/30 Mix
0.25
1 to 3
24
Humalog 75/25 Mix
0.25
0.5 to 1.5
24
Long-Acting
Ultralente[12]
6
14 to 18
18 to 24
PZI[13]
4 to 6
14 to 18
24 to 36
Glargine
1.1
N/A
24
Detemir
0.8 to 2
N/A

up to 24

These are human activity profiles.

References[]

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