Adverse drug reactions and medical and negligence
Adverse drug reactions and medical and negligence
Dr. Albert T Day, MB, FRCGP, LLM: The Medical Protection Society, Leeds LS11 5PY
DRUGS INEVITABLY PRODUCE UNWANTED EFFECTS. IF LEGAL CONSEQUENCES OF ADVERSE REACTIONS ARE TO BE AVOIDED, CONSISTENT CARE IS NEEDED AT EVERY STATE FROM DRUG MANUFACTURE TO ADMINISTRATION. DRUGS THAT ARE LICENSED SHOULD BE PRODUCED TO THE HIGHEST STANDARDS OF CURRENT KNOWLEDGE. PRESCRIBERS SHOULD BE KNOWLEDGEABLE ABOUT THE DRUGS THEY PRESCRIBE, HAVING SELECTED THEM OBJECTIVELY FROM OTHER MEANS OF MANAGING THE CLINICAL SITUATION, SHOULD PROVIDE THE PATIENT WITH INFORMATION WHICH IS SUFFICIENT TO ENABLE AN INFORMED DECISION TO BE MADE ON WHETHER TO ACCEPT THE DRUG OR NOT, AND SHOULD SEEK ADVICE IF A PRESCRIPTION DOES NOT CONFORM WITH LOCAL LAWS, AND THEY CARRY THE SAME BURDEN OF RESPONSIBILITY AS A PRESCRIBER TO WARN ABOUT ADVERSE EFFECTS OF DRUGS THAT ARE SOLD DIRECT WITHOUT PRESCRIPTION. THOSE ADMINISTERING DRUGS MUST BE TRAINED PROPERLY TO CHECK THE DRUG AND ITS DOSE, AND SHOULD ENSURE THAT THE CORRECT ROUTE OF ADMINISTRATION IS BEING USED AND THAT INJECTIONS AVOID ANY VITAL STRUCTURE.
The tort [means a wrongful but not criminal activity ] of medical negligence is a breach of duty owed to a patient, with resulting harm. What is the 'duty of care' and who owes it? In legal terms we all owe a duty of care to our neighbour; in the medical field, for 'our neighbour' substitute 'our patient' and possibly the patient's dependants also, because harm to a patient may have repercussions on his dependants. In therapeutics the prescriber has a duty of care, but the chain of care stretches both backwards to the manufacturer and forwards to the pharmacist who dispenses and the nurse who administers the drug. Harm, then, may be caused at every stage of the therapeutic process from the development of the drug through to its clinical use. Where a direct connection between the drug and harm can be demonstrated on the balance of probabilities, the patient/plaintiff may be able to obtain compensation. The question of causation is sometimes difficult to resolve, and it is often helpful t o apply the test: " if the drug had not been used in this particular way, would the harm have occurred?" This article considers medico legal aspects of therapeutics, particularly with regard to adverse drug reactions.
The duties of the manufacturer
Before a drug can be licensed for use in patients, it must be tested. Date about adverse effects in humans may be relatively sparse at this stage; thus research using human subjects should be conducted according to a protocol that has been approved by an independent ethics committee, in accordance with the Declaration of Helsinki.1 Tests using human volunteers may not be covered by laws regulating medicines; for example, in the United Kingdom (UK) the Medicines Act 19682 does not deal with studies in healthy volunteers. However, they must be told of the risks they run in sufficient detail to enable them to give properly informed consent, particularly bearing in mind that there is no direct benefit, in health terms, to the subject (Case 1).
A Canadian student volunteered to take part in a medical experiment that he was assured was perfectly safe and would involve having a tube inserted into a vein in the arm. He was not told that the tube would then be advanced into the heart. During the procedure his heart stopped and he was resuscitated by open cardiac massage. A judge decided that he had been entitled to a reasonably clear explanation of the proposed test and of the nature and expected results from it. He was awarded damages.
The healthy volunteer who suffers harm despite the approval protocol having been followed may be compensated through a 'no fault' compensation scheme operated by the manufacturers, 3 for it may well be difficult to demonstrate negligence. Patients who take part in drug trials have rather more protection. Firstly, in the European Community4 there is a duty to provide a drug that is of 'that degree of safety which patients generally are entitled to expect'. This 'strict product liability' is borne principally by the manufacturer, who may plead a defence of the level of knowledge at the time, the so-called 'state-of-the-art' defence. Secondly, there is a duty to be legal, decent, honest, and truthful in advertising the drug (Case 2).
A pharmaceutical company was convicted of issuing a false and misleading advertisement in the medical press, and their medical officer was convicted of consenting to and conniving with the issue of the advertisement.
Thirdly, there is the manufacturer's duty to warn of risk, 5,6 which may be achieved by the use of a patient information leaflet and/or a data sheet provided for prescribers, in which the manufacturer states what may be expected to be done with the product by a 'learned intermediary' (the prescriber), thus transferring a degree of responsibility to the prescriber.
The duties of the licensing authority
A licensing authority has the responsibility to ensure that testing procedures for a product have been satisfactorily devised, implemented, and completed, the result reaching an acceptable standard before a product Licence is issued. A manufacturer who markets a product in accordance with a licensing standard may defend a claim if the standard set was wrong (Case 3).
In an industrial case, an oil company was found not be the liable for injury allegedly caused by lead in petrol, because it had faithfully followed standards of production laid down by the United Kingdom's Ministry of Transport. However, this defence does not always absolve a manufacturer from all blame (Case 4).
The Irish Supreme Court decided recently that it had not been enough for vaccine manufacturers merely to comply with mandatory of minimum requirements, and that they had been negligent in releasing a batch of diphtheria, tetanus, and pertussis vaccine which by their own tests was of too high a potency and which had led to brain damage in infants.
An authority, which requires reporting of adverse effects, has a duty to act on the information contained in such reports, perhaps revoking the product licence.
The duties of the prescriber
The potential prescriber should consider carefully whether a drug is needed for a particular patient. Is the benefit likely to outweigh the risk of possible adverse effects? Are there safer ways of achieving the same benefit? Are there reasons why this particular patient is more likely to suffer harm from adverse reactions of interactions? (Case 5)
A woman who was taking a monoamine oxidase inhibitor, prescribed for her by a general practitioner on the advice of a psychiatrist, developed a cold and blocked nose for which she requested treatment. The doctor prescribed decongestant capsules for the symptoms without realising that the preparation contained isopropamide, phenylpropanolamine hydrochloride, and diphenylpyraline hydrochloride. The information on the product given in MIMS, a commonly used drug information publication in the UK, included among the contraindications for its use 'patients under treatment with monoamine oxidase inhibitors'. The patient took one capsule, became extremely ill, and was admitted to hospital where she died. Her husband successfully claimed damages.
Patients attend their doctor in good faith and with the expectation that their physician will be properly trained and will follow a standard of practice with which 'a responsible body of medical opinion' would agree; this is a test of reasonableness of a doctor's actions at the time of the incident, not at the time of the judicial inquiry.7-9 In practice, wise prescribers will for most purposes use only a small number of familiar drugs, studying and reading the data sheet or a standard work of reference before prescribing any addition to the range (Case 6).
A 73-year-old woman who had complained of a painful right knee for which numerous anti-inflammatory and analgesic drugs had previously been used without success consulted a general practitioner. He decided to use a relatively new anti-inflammatory drug and prescribed two tablets four times daily. He learned subsequently that this dose was four times the dose recommended by the manufacturer. The patient was later admitted to hospital with heart failure and anaemia and the drug was considered to have been at least partly responsible for her new illness. Compensation was paid to the patient.
The categories of practitioners who can prescribe drugs have been enlarged in the UK and elsewhere to include some registered nurses, midwives, and health visitors. They are, however, limited to prescribing only certain drugs for well demarcated indications. They are under the same general duty of care as other prescribers10. The Prescriber must warn about the possibility of relevant and significant adverse reactions in order to put the patient in a position to decide whether and how to be treated (Case 7).
A chest physician was sued on the grounds that he had failed to warn a patient who was taking Ethambutol that if his vision changed he should stop the drug and consult the physician immediately. The physician claimed that he had given this warning when the drug was first prescribed and at each subsequent visit of the patient. Unfortunately, the doctor had made no entry in his notes concerning the warning. He was found by the judge to have been negligent, and substantial damages were awarded to the patient.
The scope and method of the explanation if for the doctor to decide, subject to a duty to answer truthfully and frankly any direct questions put by the patient and bearing in mind the words of a judge: ' every human being of adult years and sound mind has a right to determine what shall be done with his own body'. Another judge stated that 'an individual patient must, in my view, always retain the right to decline treatment, however irresponsible or foolish this may appear in the eyes of his medical advisers'. Doctors may need to include in their advice to patients a warning that certain foods are to be avoided, that driving could be hazardous because of drowsiness (Case 8), or that should be avoided because of potential harm to the fetus.
A general practitioner was alleged to have prescribed a tranquillizer without warning the patient of possible side effects. The patient had taken two tablets and soon afterwards had driven a car and been involved in a road accident. The manufacturer's drug data sheet contained a warning against driving while under treatment with the drug. 'The patient was paid damages.
It may be necessary to obtain the agreement of the patient for routine monitoring of blood samples (Case 9).
A man was treated in hospital with gentamicin for a ruptured bladder and septicaemia. The patient's blood urea concentration was raised, but no measurements of blood gentamicin levels were made while the patient was in hospital or subsequently. He was discharged from hospital still taking gentamicin and later he developed deafness that thought to have been caused by gentamicin. A successful claim form damages was made by the patient.
Clearly, the doctor ought to carry out relevant baseline investigation (for example, a blood urea measurement or a test) before starting treatment, and should provide a clear set of instructions telling the patient what to do if an adverse event occurs. The right of young people who are sufficiently mature to understand issues in their medical management to take their own decisions has been increased progressively in the past fifteen years in the UK.11-13 Prescriptions must be legible. Any harm that occurs because of a misinterpretation of the writing on a prescription is the responsibility of the doctor and the nurse or pharmacist14 (Case 10).
A child died of Theophylline poisoning following gross overdosage. because the doctor's handwriting on the prescription sheet was so difficult to read that two excessive intravenous doses of 500 mg were given by the nurses instead of the correct does of 50 mg.
The duties of the pharmacist
As a professional, the pharmacist has a duty of care to the patient both to supervise the sale of 'over-the-counter' (OTC) drugs which are available only in pharmacies and to dispense safely and correctly drugs which have been prescribed by a doctor. OTC drugs may be unsuitable for an individual patient for a number of reasons. If approached for advice, the same duty lies on the pharmacist to counsel, warn, and act reasonably as it does on any prescriber. In addition, there is a duty to contact the prescriber if any question about a prescription arises. (Case 11)
A Doctor prescribed an antibiotic for a patient, but the pharmacist misread the very badly written prescription and wrongly dispensed an antidiabetic drug. The patient suffered severe hypoglycaemia and brain damage. The doctor's legal representative claimed that the pharmacist should have contacted the doctor and queried the does of 3 tablets 3 times daily (which would have been most unusual for the antidiabetic drug), but it was finally agreed that both the doctor and the pharmacist had been negligent.
Duties in administering drugs
Just as care is needed in prescribing drugs, so is care needed in their administration. Knowledge of where to place an injection to order to avoid a nerve or other structure is expected of a practitioner, so that an error speaks for itself as a negligent act (Case 12).
A patient was given a corticosteroid preparation by injection into the upper arm, although the manufacture's instructions stated clearly that the drug should only be given by deep intramuscular injection into the buttock, because of the danger of fat atrophy. The patient developed skin changes and loss of subcutaneous tissue, for which she successfully claimed compensation.
Errors in giving a drug by the wrong route can be catastrophic
Two junior doctors administered cytotoxic drugs to a young man with leukaemia. It was intended to give him intravenous Vincristine and intrathecal Methotrexate, but the Vincristine was given intrathecally and the patient died. The doctors were found guilty of involuntary manslaughter, though their convictions were quashed on appeal.
The potential for disaster is ever present with drugs, so basic procedures for checking are always important (Case 14), particularly with injectables and especially when a doctor is provided with a syringe filled by someone else (Case 15).
A patient with Burkitt's lymhoma was treated with a regimen that included administration of intrathecal Methotrexate. The drug is available in solutions of 1 mg per ml and 50 mg per ml. He was erroneously given the stronger solution and became extremely ill.
During a heart operation on a six month-old baby, the wrong drug was administered. A junior hospital doctor had been given instructions by the anaesthetist about the drugs to be used during the operation; one of these was Protamine Sulphate. The junior doctor drew up the drugs into syringes and labelled them. The contents of a syringe labelled "Prot A" were administered towards the end of the operation; the baby suffered a cardiac arrest and all efforts at resuscitation failed. Investigation revealed that the syringe had contained not Protamine Sulphate but potassium chloride. It was later discovered that the containers and ampoules of the two drugs were identical in shape, colour, and size. The junior doctor admitted that he failed to read the label on the ampoule before drawing up its contents. Damages were paid to the parents.
IMPORTANCE OF REPORTING ADVERSE DRUG REACTIONS
Adverse drug reactions very often produce symptoms of signs that may be difficult or impossible to distinguish from those of naturally occurring disorders. Consequently, doctors should never dismiss suspicions that a drug might have been responsible for a patient's illness merely because they think the evidence is flimsy. Instead, they should report their suspicions, however tenuous, to their national drug safety organization. They have a duty to make their observations known for they may be the first of their kind and may alert other doctors to the possibility of previously unrecognized adverse effects of treatment, and so protect patients against harm. The following are examples of reactions that should always be reported: anaphylaxis, blood dyscrasias, congenital abnormalities, endocrine disturbances, severe CNS effects, haemorrhage, jaundice, ophthalmic signs and symptoms, severe skin reactions.
In the United Kingdom, The Committee on the Safety of Medicines wishes to be informed of reactions of these kinds, and doctors will find the pre-paid yellow reporting forms most convenient for the purpose. [Readers are aware that the system of monitoring ADR is almost non-existent in India.]
Reproduced from Adverse Drug Reaction Bulletin (UK): No. 172, pp651-654, June 1995
We are thankful to the publishers, M/S Chapman & Hall (UK) for the permission and also for waving the royalty on this account.