Exam 4: Diabetes Pharmacology Flashcards
Two reasons for hyperglycemia in DMII:
Lack of insulin production once β cells fail
Cells resistant to insulin action
Insulin produced by:
β cells in islets of Langerhans
β cells secrete insulin in response to:
↑ circulating glucose
Insulin released as:
Proinsulin (precursor)
Structure of insulin:
Small protein chain of 21 amino acids linked by two disulfide bridges to a β chain of 30 amino acids
Effects of insulin:
Glucose into cells Glycogen creation Uptake of amino acids, Phos, K, Mg Protein synthesis/inhibited proteolysis Fatty acid/TG synthesis ↓ lipolysis DNA/gene regulation
Portal circulation receives basal insulin rate of:
1U/hr
With meals, insulin secretion increases:
5-10x
Average daily requirement of insulin:
40U
ANS influence on insulin secretion:
α stimulation ↓ insulin
β and PSNS stimulation ↑ insulin
History of making insulin:
Stage 1: insulin extracted from pigs/cows
Stage 2: replaced one ‘wrong’ amino acid to make it identical to human
Stage 3: Make yeast or e.coli produce it instead
Rapid-acting forms of insulin:
Lispro (Humalog)
Aspart (Novalog)
Glulisine (Apidra)
Short-acting form of insulin:
Regular (Humulin R/Novolin R)
Intermediate-acting form of insulin:
NPH (Humulin N/Novolin N)
Long-acting forms of insulin:
Glargine (Lantus)
Detemir (Levemir)
Ultralente
Delivery forms for insulin:
SQ
IV
Inhaled
Insulin mixtures available:
R/NPH
Rapid/NPH
Long-acting insulin used to mimic:
Basal insulin rate
Insulin mixture incompatibilities:
Do not mix glargine with others
PK of IV regular insulin:
E1/2t of IV bolus: 5-10 min
Duration: 30-60 minutes
Metabolized in liver/kidneys by proteolytic enzyme
Insulin’s relatively long duration is due to:
Tightly binding to receptors
Formulation to use IV:
U-100 (100 units/ml)
Onset/peak/duration of rapid-acting insulin (lispro):
Onset: 10-15 min
Peak: 30-60 min
Duration: 3-5 hrs
Onset/peak/duration of short-acting insulin (regular):
Onset: 30-60 min
Peak: 1-5 hrs
Duration: 5-8 hrs
Onset/peak/duration of intermediate-acting insulin (NPH):
Onset: 1-2 hrs
Peak: 6-10 hrs
Duration: 16-20 hrs
Onset/peak/duration of long-acting insulin (glargine):
Onset: 2-6 hrs
Peak: none
Duration: 24 hrs
Delivery methods for insulin:
Syringe
Pens
Jet injectors
Insulin pumps
A/E of insulin injection:
Site rxns Lipodystrophy at site Protamine allergy Weight gain Hypoglycemia!!
S/s of hypoglycemia:
Diaphoresis Tachycardia HTN CNS agitation Seizures Coma
Drugs that oppose the hypoglycemic effects of insulin:
ACTH
Glugacon
Estrogens
Drug that decreases insulin release/mobilizes glucose:
Epinephrine
Drugs that prolong insulin duration:
Tetracycline
Chloramphenicol
Salicylates
Drugs that increase hypoglycemic effects of insulin:
MAOIs
In a type I diabetic 1 U will ↓ BG by:
40-50 mg/dL