Chronic Diabetes Case B

Presented by: Owen Naidoo

Abdullah OsmanChristine Tanzil

Ayse Togac

Ms SP, aged 34 years, has schizophrenia. She is

currently being treated with Olanzapine (last 6

months) & is doing well.

However she has put on 7kg in weight since commencing the Olanzapine & her doctor

is concerned that she is developing diabetes.

What is Olanzapine? An atypical antipsychotic, that is

indicated in schizophrenia, related psychoses and acute mania.

ADR’s: somnolence, weight gain, raised glucose, exacerbation of diabetes.

C/I’s: CNS acting drugs, alcohol, smoking, drugs that increase the QTc interval.

TYPE 1 Diabetes

Primarily immune mediated destruction of beta cells.

Requires lifelong insulin:>15% of cases.

Onset usually in earlier years Px is lean, ketonuria, later

ketoacidosis.

TYPE 2 Diabetes Caused by either:

abnormal insulin secretion failure to suppress hepatic glucose

production insulin resistance in target tissue

Strongly genetically determined in >80% of cases.

Later onset Px is usually overweight

Describe the current guidelines for the diagnosis of diabetes

as defined in Australia.

PART I

SUMMARY OF DIAGNOSIS (Therapeutic Guidelines Online

2003)

Explain whether atypical antipsychotics such as Olanzapine can cause

weight gain, hyperglycaemia or

diabetes.

PART II

10 patients with

Olanzapine-induced

hyperglycaemia

8 patients Hyperglycaem

ia resolved

2 patients need oral

hypoglycaemics

Hyperglycaemia again

Olanzapine discontinue

dIn 2

patients Olanzapine rechalleng

ed

Is the data consistent for Clozapine? What is the strength of this evidence?

7 patients with

clozapine-induced

hyperglycaemia

4 patients hyperglycaem

ia resolved

3 patients need

insulin

Hyperglycaemia again

Clozapine discontinue

d

Reintroduction of Clozapine

82 patients treated

with Clozapine over a 5 yr period

43 patients had 1 episode of increased BGL’s

19 patients had 2 episodes of increased BGL’s

30 patients were diagnosed with Diabetes Mellitus

What precautionary clinical chemistry tests should be performed & why?

Full blood count Olanzapine may cause neutropenia as

a rare adverse effect. Liver function tests

Olanzapine may cause an elevation of liver transaminases as an infrequent adverse effect.

Patients with hepatic dysfunction require a smaller dosage of Olanzapine.

(cont)

Blood glucose Patients may have hyperglycaemia as

a common adverse effect of Olanzapine usage.

Renal Function tests Patients with renal dysfunction

require a smaller dosage of Olanzapine.

Ms SP is a chain smoker.

What impact does smoking have on Olanzapine?

PART III

Effect of smoking????? Olanzapine is metabolised by CYP1A2.

Smoking induces the CYP1A2 metabolism of Olanzapine.

In smokers the clearance of Olanzapine is higher, on average, than the clearance in non-smokers.

Therefore there may need to be an increase in the Olanzapine dose in a smoker.

The clearance of Olanzapine is 33% lower and the terminal elimination half-life is 21% longer in non-smokers compared to smokers.

The techniques used in monitoring glucose in

urine.

PART IV

What does urine glucose testing measure?

A urine glucose test determines whether or not glucose is present in the urine.

Glucose will overflow into the urine only when the blood glucose level is high, that is above 10mmol/L

How is glucose in urine monitored? A small amount of urine is collected

into a clean, dry container The dipstick analysis is performed as

soon as possible after the collection (ideally within 30minutes).

The reagent strip is dipped into the urine where it measures glucose levels using the glucose oxidase

(cont)

The Glucose Oxidase method, is a sequential enzymatic reaction where glucose interacts with glucose oxidase to produce hydrogen peroxide, which oxidizes the indicator chemical to produce a colour change. The colour change s related to the amount of glucose present in the urine sample.

“The diagram on the disc…”

Problems associated with interpreting these results:

a) It does not reflect your blood glucose level at the time of testing, instead, it gives an indication of your BGL over the past several hours

b) It does not give any information about low blood glucose levels, as glucose is only found in the urine when the BGL is above 10mmol/L.

(cont)

c) The results of a urine glucose test are influenced by the volume and concentration of urine that you pass

d) Difficulty in interpreting colour changes

e) If not read at specific time, results prone to error.