A bitter pill to swallow: expert evidence assisted in finding of no breach or causation in antibiotic allergy claim against doctor

The issues in dispute revolved around:

1. Dr Swenson’s alleged lack of reasonable care taken to identify the hospital attended and the drug taken by Mrs Filmalter in South Africa in 2007;
2. whether Dr Swenson should not have prescribed Mrs Filmalter Norfloxacin without accessing these records, and whether Dr Swenson should have waited until the entirety of Mrs Filmalter’s pathology test results returned before prescribing Norfloxacin;
3. whether Mrs Filmalter was diagnosed with photosensitivity and whether the 2014 ingestion of Norfloxacin caused her to develop the illness; and
4. whether the 2014 ingestion of Norfloxacin caused Mrs Filmalter to be diagnosed with cerebral vasculitis and suffer a stroke in 2017.

The parties made submissions relating to section 22 of the CLA, which discusses the standard of care for professionals, and sections 60 and 61 of the ACL pertaining to the supply of a service with due care and skill and the guarantee that the service is fit for purpose.

The court examined whether Dr Swenson's diagnosis and prescription were appropriate given Mrs Filmalter's medical history and whether Dr Swenson had informed Mrs Filmalter of the risks and alternatives adequately. Dr Swenson argued she was not negligent in her treatment and advice of Mrs Filmalter, had not breached ss 60 and 61 of the ACL, and that Mrs Filmalter had not suffered from an allergic reaction nor been rendered photosensitive. Dr Swenson also argued that the stroke that Mrs Filmalter suffered in 2017 was not related to the ingestion of two tablets of Norfloxacin on 8 February 2014.

Evidence from various consultations and medical records was considered, including the credibility of the testimonies. Extensive medical history of Mrs Filmalter was presented, which was considered in the context of evidence put forth by Dr Swenson, Mrs Filmalter, and her husband. Dr Swenson’s evidence largely lined up with the clinical notes and was considered credible, while there was significant doubt as to the credibility of both Mr and Mrs Filmalter due to inconsistencies and exaggerations in their evidence. The Court found that Mrs Filmalter exaggerated her symptoms and diagnosis recorded during a 2007 visit to a South Africa hospital when compared to the actual clinical notes. Further, the Filmalters gave evidence that Mr Filmalter was at a GP consultation Mrs Filmalter had with Dr Swenson – when Dr Swenson’s evidence and the clinic notes indicate that he was not present.

Dr Swenson was aware of Mrs Filmalter’s allergy to penicillin, sulphur and another ‘unknown antibiotic’. When it was discovered that Mrs Filmalter had a urinary tract infection from the return of the first tranche of pathology test results, and required antibiotics, Dr Swenson looked up the therapeutic guidelines for a class of antibiotics which were not related to penicillin or sulphur. The guidelines suggested that the best choice in those circumstances was the Fluoroquinolone class, being either Ciprofloxacin or Norfloxacin. Dr Swenson explained that she made the choice of Norfloxacin because Ciprofloxacin is more widely used (and therefore more likely to be the ‘unknown antibiotic’ that Mrs Filmalter supposedly reacted to in 2007). Because Norfloxacin was not widely used, Dr Swenson looked at the product information and considered the potential side effects. After determining that Norfloxacin was the best drug to use, Dr Swenson then needed an authority approval because the drug was not often used and kept for serious cases. Dr Swenson got authority from a pharmacist out of the Pharmaceutical Benefits Scheme only after she had first discussed the prescription of that medication with Mrs Filmalter. The Court accepted that Dr Swenson explained the side effects of the drugs, including photosensitivity, and talked through the possibility of an allergic reaction with Mrs Filmalter. 

The Court further found that in light of Mrs Filmalter’s medical history, the first tranche of test results received by Dr Swenson and the symptoms described by Mrs Filmalter, it was proper practice for Dr Swenson to strongly advocate for the option presented to Mrs Filmalter of taking the antibiotic. The second tranche of test results were returned later, and while they were unremarkable and indicated Mrs Filmalter may not have had a urinary tract infection, the Court accepted that the discussion Dr Swenson made to prescribe the antibiotic was the clinically correct one.

In terms of the complaints of photosensitivity, the first recorded complaint to a medical practitioner by Mrs Filmalter of suffering from any type of photosensitive reaction was not until 26 February 2014 – 15 days after the ingestion of the Norfloxacin on 9 February 2014. The symptoms complained of were also found to be far less severe than described by the Filmalters in their evidence. Mrs Filmalter presented at a number of hospitals and consulted a number of dermatologists, but no medical record of skin rashes, blistering or lesions were documented. There were no objective findings documented to support her claim of photosensitivity.

There was also found to be no possible link between the ingestion of Norfloxacin in 2014 to the presentation and then diagnosis of cerebral vasculitis and an eventual stroke in 2017.

The Court found that there was an insufficient causational link between Mrs Filmalter’s ingestion of Norfloxacin and the development of symptoms that were not confidently concluded to be photosensitivity. The Court found instead she may have suffered from a minor allergic reaction, but the Norfloxacin did not cause any type of long-term photosensitive illness or cerebral vasculitis due to its half-life of around three hours. Further, the stroke suffered in 2017 was likely an embolic stroke, where Mrs Filmalter had a background of several risk factors and, as expert Professor Katelaris put it to the court, ‘common things happen commonly’.

To assist with determining causation, the Court considered the weight of both experts engaged by the parties at [214]:

‘…Dr Lynch burst out laughing and could not contain his laughter, such that court was adjourned to enable Dr Lynch to compose himself. The laughing was most inappropriate. It was, in my view, a very personal attack upon Dr Swenson which was most unwarranted. That is not the hallmark of an independent witness.’

‘As discussed above, it seems to me that Dr Dickinson's opinions ought to be accepted over Dr Lynch's opinions, essentially because Dr Dickinson's opinions are logical and reasoned and based upon the correct assumptions. Dr Lynch's opinions are not based upon the correct assumptions, are not well-reasoned and as demonstrated above, Dr Lynch has used hindsight bias and circular reasoning. Dr Dickinson gave his evidence in a careful, logical and properly reasoned manner. He made multiple concessions, gave every appearance of being a completely independent and unbiased expert. I accept his opinions.’

The Court discussed the New South Wales decision of Dean v Pope and what is ‘peer professional opinion’ of ‘competent professional practice’ at [226] and [227]:

‘…the evidence does not need to identify a specific practice as such, but rather whether there is a way of professional practice which can be identified as being a widely accepted (as competent professional practice at the relevant time) manner of acting (and that seems practical), per Ward P in Dean v Pope at 233. As set out by Ward P at [235] and [236] and Brereton JA at [317] in Dean v Pope, accepting the reasoning of Basten JA and Simpson AJ in Sparkes, it was emphasised that the defendant need not bring evidence of a particular specific or established practice, but rather a consideration made by reference to how an assessment of the circumstances would be undertaken by a knowledgeable and experienced practitioner.

In Grinham J Forrest J at [190] accepted an ‘expert’ general practitioners reliance on attendance at a large number of professional conferences, accreditation processes and surveys as evidentiary basis for a competent wide spread medical practice.’

In determining the plaintiff’s arguments under sections 60 and 61 of the ACL, the court concluded at [256]:

‘… when the culture pathology was received on 12 February 2014, the appropriate conclusion was that Mrs Filmalter was not likely to be suffering from an infection, and therefore the prescription of any antibiotics was wrong. That is, with the benefit of the wisdom of hindsight, Dr Swenson was wrong in her prescription of any antibiotic. It seems to me, however, that the time at which judgement ought to be made, at least in a medical negligence case, as to whether the services rendered by a medical practitioner were reasonably fit for the purpose for which they were provided, ought to be at the time when the medical service was provided. As discussed above, as at 8 February 2014 Mrs Filmalter had a probable urinary tract infection which may have progressed with fatal consequences. Prescription therefore of a class of antibiotic differing from those to which Mrs Filmalter had previously suffered from allergic reaction was, in my view, a service which was reasonably fit for the purpose for which it was provided and was a service rendered with due care and skill.’

                                                                                                 (emphasis added)

The court therefore determined that Dr Swenson had not breached her duty of care to Mrs Filmalter or the ACL. The judgment was for the defendant, as it was concluded that Dr Swenson's treatment and advice were in line with competent professional practice.