Page 53 - Demo

CONTINUING PROFESSIONAL DEVELOPMENT
MEDICATION MYSTERIES
Medical history
Assessment
Anna appears to be suffering from a form of delirium. There are a number of potential causes for her current symptoms.1,2
Urinary tract infection – Anna is not displaying any other symptoms of a urinary tract infection and has no frequency of urination. Her urine output is good and clear.
Constipation – Anna states that her bowel movements are normal.
Pneumonia – Anna does not display any respiratory signs or symptoms. During her recent complete health check, she underwent a spirometry assessment and her GP was pleased with her lung capacity.
Dehydration – Electrolyte disturbances associated with dehydration are a common cause of delirium. Anna and her husband state that she drinks plenty of water each day. She has also been drinking an oral rehydration solution several times a day, as she has been feeling quite nauseous of late.
Thyroid issues can contribute to reversible delirium. Anna has had recent pathology performed by her GP and her thyroid tests were normal. Anna has no previous history of thyroid problems.
Concussion, stroke, or myocardial infarction –
Anna has not hit her head recently nor has she
had a stroke or heart attack. Her recent complete health check showed she was in good health with no abnormalities detected on her ECG. Her blood pressure was normal and no abnormal heart sounds were detected.
Medicines – Certain medicines (e.g. anticholinergics, serotonergic agents), illicit drugs, and alcohol can cause symptoms of delirium. Anna’s symptoms seem consistent with a delirium associated with serotonin syndrome (see Table 1).4
What medicines do you take for the pain?
Anna took anti-inflammatory medicines for several years to relieve the pain of arthritis. However, the general practitioner (GP) was concerned about their effect on her stomach and changed Anna to Panadol Osteo. Anna has recently had a fall that has exacerbated her arthritis pain. The GP changed the paracetamol SR to a combination product – paracetamol and codeine – but this did not control the pain effectively. The GP changed Anna back
to paracetamol SR, added oxycodone 5 mg when needed and also added tramadol 50 mg, to be taken when the pain did not improve.
To gain a better idea of what is occurring, you ask Anna the following questions in a general discussion format:
Are you taking any other medicines for pain relief? Are you taking any complementary medicines?
Anna has tried fish oil capsules at a dose of 1 g fish oil daily for pain relief, but this did not help. She has not tried heat or exercises in a heated pool, nor has she attended a pain clinic for assessment and treatment of her arthritis. Anna does not find any particular foods make her pain worse. One of her friends has suggested turmeric capsules, but she is reluctant to try these until she speaks with her GP.
Has the GP conducted any blood tests recently and do you know the results?
Anna has regular blood tests as she has a history of low iron due to heavy menstrual bleeding. The GP did not comment that there were any issues when she saw him for a full review a month previously.
Why are you taking the citalopram?
How long ago did you start citalopram 40 mg?
Anna has been taking citalopram 40 mg daily for about 12 months, to treat anxiety and depression related to her pain. She has not seen any other doctors or specialists and has had the same GP for over 20 years. Anna is no longer driving a car as she feels disorientated, cannot settle and does not feel herself. She does not feel unwell, but she feels very confused. She mentions that when walking, she has a peculiar gait. Anna describes her sleep as being disturbed and she is having graphic nightmares, which are unusual for her.
“The GP changed Anna back to paracetamol SR, added oxycodone 5 mg when needed and also added tramadol 50 mg, to be taken when the pain did not improve.”
Table 1. Drugs that may contribute to serotonin toxicity when combined with tramadol
Class
Drugs
Antidepressants
MAOIs (including moclobemide)
SNRIs (duloxetine, venlafaxine, desvenlafaxine)
SSRIs (citalopram, sertraline, fluoxetine, paroxetine, escitalopram, fluvoxamine)
Mirtazapine, St John’s wort
Opioids
Dextromethorphan, fentanyl, pethidine, tramadol, tapentadol
Stimulants
Amphetamines, phentermine
Others
Illicit drugs (e.g. ‘ecstasy’, LSD, cocaine), rasagiline, selegiline, linezolid, lithium, methylene blue, tryptophan
References: Takeshita5;Sansone6;NSW Therapeutic Advisory Group7
Australian Pharmacist January 2017 I ©Pharmaceutical Society of Australia Ltd. 51