9 - Diabetes and Drugs Flashcards
What causes the secretion of insulin and what is it inhibited by?
- Protein secreted by B cells which is why it has to be injected not orally
- Stimulated by: increased glucse, glucagon, incretins (GLP-1 and GIP), parasympathetic activity (M3)
- Inhibited by: lowered glucose, cortisol, sympathetic activity (a2)
What are the different functions of insulin in the body?
- Stimulates uptake of glucose into liver, muscle and adipose tissue
- Inhibits gluconeogenesis
- Inhibits glycogenolysis
- Promotes fat uptake
What are some drugs that can be a risk factor for the development of type 2 diabetes? (drug induced diabetes)
What are some symptoms of type 1 diabetes?
- Hyperglycaemia
- Polyuria
- Polydipsia
- Weight loss
- Fatigue/lethargy
Raised plasma glucose without symptoms not sufficient for diagnosis
How is insulin absorbed and administered?
- Absorbed into the blood stream by subcut injection e.g upper arms, buttocks
- Given 15-30 mns before eating as plasma concentration highest 2-3 hours after giving and short half life
- Given IV if emergency
- Has to be straight to blood stream as it is a protein so would be broken down enterally
What substances can be given with insulin to modify its absorption?
- Protamine: makes insulin short acting, broken down quicker
- Zinc: makes insulin long acting, longer time to absorb
What are some side effects of injecting insulin?
- Hypoglycaemia
- Lipodystrophy if using same sites constantly
- Allergies
- Painful injections
- Lipoatrophy
Fill in the following table regarding different formulations of insulin.
Provide an example of the following and when they need to be administered:
- Rapid acting insulin
- Short acting insulin
- Intermediate acting insulin
- Long/very long acting insulin
- Insulin aspart (Novorapid): inject just before eating
- Soluble Insulin (Actrapid or Humulin S): inject at least 15-30 minutes before eating several times daily to cover meals
- Isophane Insulin (NPH)
- Insulin degludec or insulin glargine
What are some contraindications for the use of insulin?
- Increase dose of insulin if patient using steroids
- Be careful with other hypoglycaemic drugs
What are the key challenges for patients with Type 2 diabetes in terms of patient adherence and quality of life?
- Weight gain (or fear of weight gain)
- Risk of hypoglycaemia (or perceived risk)
What is basal bolus dosing?
- Injection at each meal, attempts to roughly mimic how a non-diabetic person’s body delivers insulin and then a basal dose constantly
- Mimics insulin levels in healthy patient
When should you suspect a DKA and how would you treat it?
- First give fluids as diuresis from glucose
- Then give IV insulin
- Give glucose and K as can turn hypokalemic from insulin even though appear hyperkalemic
What are three different regimens that can be used for insulin injections?
- Basal: inject a long acting insulin so you have the same basal level of insulin at all times
- Basal-Bolus: use a long acting insulin but before eating you inject a fast/short acting insulin so insulin levels increase when eating
- Intermediate: 2 injections a day of combined intermediate and short acting
Can get a insulin pump but very expensive
What is the pathophysiology of type 2 diabetes and how can it be treated in general terms?
- Decrease in sensitivity of insulin receptors initially overcome by increased pancreatic insulin secretion
- Glucotoxicity from fatty acids and ROS lead to B cell dysfunction
- Treat: change lifestyle, hypoglycaemic agents and eventually insulin
What are the NICE guidlines for type II diabetics needing glucose lowering therapy?
- HbA1c >6.5% use metformin, if can’t tolerate use DPP-4i or SGLT2i OR a modified release metformin
- HbA1c>7.5% consider dual therapy and if not responding then triple therapy and if still not responding think about insulin therapy
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What is the mechanism of action of metformin? (biguanide)
FIRST LINE THERAPY
- Decrease hepatic glucose output by decreasing gluconeogenesis and glycogenolysis
- Increases glucose utilisation in skeletal muscle by decreasing insulin resistance
- Suppresses appetite so limits weight gain
- Decrease insulin resistance
What are some side effects of metformin?
- GI symptoms (nausea, loose stools, diarrhoea)
- Vitamin B12 deficiency (uncommon)
- Lactic acidosis (rare
USE MODIFIED RELEASE TO LIMIT SIDE EFFECTS