|
print view
INTRODUCTION Medication is probably the most readily available treatment for mental health problems. Indeed, prescriptions of medication for mental health problems have increased greatly in recent years in the UK. For example, antidepressant prescriptions almost doubled between 1975 and 1998. This is sometimes criticised by patients and others as ìjust medicating the problemî, and certainly the manufacturers of these drugs have prospered. Against that background, however, there has during the same period been a tremendous change in psychiatric practice, with patients being resettled (largely successfully, whatever the press may say) from old hospitals into the community. Modern psychiatric practice largely takes place in the community, with only a few inpatient beds required. In my opinion, the increase in the use of psychotropic medication has probably played some part in this success story.
MECHANISMS OF ACTION Medication works partly through a specific effect, and partly through a placebo effect. Consider a group of patients on antidepressant medications; if they are randomly divided into one half getting the medication, the others getting a dummy pill, then about 50% of patients on antidepressants might get better over six weeks, and about 30% of those on the dummy pill ( see for example).
These results would be fairly typical. They show a substantial non-specific response, plus a further effect, of roughly similar extent, specifically from the drug itself.
PRESCRIBING WITH CONFIDENCE It follows that practitioners must make full use of both aspects of the effectiveness of the drugs they prescribe. If the medication is given with hope and confidence, plus an explanation of the probability of help from it, coupled with realistic advice about side-effects, then the likelihood of the medication helping the patient is greatly increased.
REAL-LIFE EFFECTS OF MEDICATION However, the effect of medication tends to be partial, rather than a complete cure, and often depends on continuing with the medication and some time (for example months). Premature stopping of the medication tends to be followed by return of symptoms in many cases.
Substantial overall progress often depends on combining the medication with other sorts of treatment such as psychotherapy and general rehabilitation.
I now consider the various categories of medication, commonly used in psychiatry.
ANTIDEPRESSANTS are the most commonly prescribed psychiatric medication. They are possibly misnamed, as they work to some extent in various conditions:
- depressive illness
- anxiety disorders, including PTSD
- chronic pain
This probably reflects overlap between the conditions indicated, as well as multiple pharmacological actions at the biochemical level.
There are three main groups of antidepressants:
- SSRIs (selective serotonin reuptake inhibitors, e.g. Prozac)
- MAOIs (monoamine oxidase inhibitors)
-
tricyclics (this refers to their three ring chemical structure, e.g. amitriptyline)
-
plus other drugs which do not fit into the above categories.
SSRIs These are the most widely prescribed type. They have been on the market for about 10-15 years. They include:
- fluoxetine (trade name Prozac)
- paroxetine (Seroxat)
- sertraline (Lustral)
They are very popular in general practice, where they are often associated with improvement in the common milder, situational reactions.
SSRIs are indicated for depression and for some types of anxiety, such as social phobia.
SIDE EFFECTS OF SSRIS can be troublesome, including anxiety and agitation in the first few days; some authorities advise that this initial period be "covered" by the simultaneous prescription of an anti-anxiety drug such as a benzodiazepine.
Gastrointestinal disturbances and insomnia can also be prominent.
Disturbance of sexual function, including loss of libido and anorgasmia, has fairly recently been recognised as a special problem with these drugs.
MAOIs (MONOAMINE OXIDASE INHIBITORS) are now- unfortunately- mainly of historical significance. They are potent antidepressants, but have an unusual dietary restriction. Because of the "cheese reaction", patients will experience a potentially dangerous rise in blood pressure if they eat cheese, Marmite or broad bean pods- or drink Chianti: all of these contain tyramine.
Although they are safe if the patient sticks to the diet, the potential risks are difficult hard to convince patients of, especially as few psychiatrists use the MAOIs often enough to have the confidence which comes with daily use.
They are therefore probably underused. They should certainly be considered if the patient has a depressive illness which fails to respond to standard medications.
TRICYCLIC ANTIDEPRESSANTS can be thought of as the "Land Rovers" of antidepressant medication. The design is a bit ancient (up to 50 years old, in fact) and the ride may not be especially smooth in terms of side effects. However, when the going gets tough, they don't give up and may be more likely to get you through than some of the newer "lite" medications.
Commonly prescribed tricyclics include:
- amitriptyline
- imipramine
- trimipramine (Surmontil)
TRICYCLIC SIDE EFFECTS include dry mouth and constipation. These can be troublesome, but are at least predictable and dose-related (unlike the less-predictable adverse effects of SSRIs).
Some of the "side effects" are useful in some circumstances, for example:
- drowsiness: can help insomnia if given at night
- sedation: can help anxiety if given during the day
USES OF TRICYCLICS As indicated, in small doses they can be useful symptomatic remedies for anxiety and insomnia, where they are one of the alternatives to the benzodiazepines, now that the latter drugs have become less used because of their addictive potential.
Their main use is for depressive illnesses, especially in secondary care, when the patient will often have been tried unsuccessfully on SSRIs before referral.
GENERAL PRINCIPLES OF ANTIDEPRESSANT MEDICATION USE. Antidepressants usually help somewhat, though are seldom curative. They are often stopped too soon.
If it is a mild condition, short term treatment with a mild medication such as an SSRI, or low doses of a tricyclic, may be associated with a satisfactory outcome.
In more severe conditions, longer term treatment with full doses of a tricyclic or similar agent may be required.
Frequent changes of medication should be avoided. The antidepressants have much more in common with each other than they have differences, and the likelihood of a change in medication from drug A to drug B causing a dramatic improvement in therefore low.
Prevailing wisdom is to increase the dose of the first drug to the maximum, and then to consider adding in a second drug, for example, a benzodiazepine, or a mood stabiliser, if the response is not adequate.
ANXIOLYTICS (MINOR TRANQILLISERS) This refers mainly to the benzodiazepines, such as Valium (diazepam).
They are effective remedies for anxiety symptoms in the short term; they were very widely prescribed forms the 1960s onwards. They replaced the barbiturates, which had been widely prescribed for the same reason in the preceding decades, but fell out of favour because they were addictive and fatal in overdose to respiratory depression.
The benzodiazepines certainly represented in advance, in that they were non-fatal in overdose. Unfortunately, they proved to be just as addictive as their predecessors. Patients need gradually to increase the dose in order to achieve the same effect (habituation) and suffer withdrawal symptoms if the substance is stopped suddenly.
Accordingly, these drugs are now regarded as suitable only for short-term treatment, and many doctors are nervous about them, and reluctant to prescribe them at all.
This is something of a pity; the pendulum has swung too far against them in my opinion. They are an effective remedy for anxiety in the short-term, and if the patient can be relied upon not to increase the dose, and not to use the medication regularly, they can be a very useful treatment for certain forms of anxiety. For example, a patient with phobic anxiety may experience relief from taking a tiny, sometimes an almost homeopathic, dose just before entering the feared situation. Some patients even find relief from knowing that they have got a bottle of pills on them, touching the bottle even thinking about it can have an almost talismanic effect.
USES OF BENZODIAZEPINES They are effective in various anxiety state in the short-term, and possibly also in mild, mixed anxiety/depressive states, as commonly seen in general practice.
They can be very helpful in the short term, for example, following a bereavement, but are usually unhelpful in long term use.
They are sometimes used as an add-ons (so-called adjuvants), for example, when a patient has responded partially to an antidepressant, but there are still residual depressive symptoms.
There remains an important role for benzodiazepines emergency management of agitation and disturbed behaviour in inpatient psychiatric care, when lorazepam, 1-2 mg, can usefully propitiate the effect of antipsychotic medication and calm the patient.
ANTIPSYCHOTICS (MAJOR TRANQUILLISERS)
Commonly prescribed drugs of this type would include:
- chlorpromazine
- haloperidol
- olanzepine
The main use of these drugs is in schizophrenia and other psychotic disorders, including mania, depressive psychosis and schizoaffective disorder.
These conditions are not usually the result of injury, and so may not fall frequently to the lot of the personal injury lawyer. However, they are matters which frequently come up in the criminal courts, where questions such as fitness to plead, state of mind at time of the offence and advice as to disposal are commonly raised.
These drugs are also powerful sedatives, and may therefore be used to control education or disturbed behaviour in psychiatric inpatients settings.
Small doses can be helpful tranquilisers in commonly encountered states of agitation, anxiety, etc. in outpatient practice; I find olanzepine 2.5 mg - 5mg as required to be a satisfactory treatment for agitation in my outpatient practice.
SIDE-EFFECTS OF ANTIPSYCHOTICS The majority of patients will experience some side-effects from this type of medication.
The older drugs such as haloperidol and chlorpromazine (typical antipsychotics) typically cause
- dry mouth
- restlessness of the limbs (akathisia)
- stiffness and shakiness of the muscles (so-called extra pyramidal side-effects, EPSE, the "pyramids" referred to being part of the spinal cord involved with the control of muscular movement brackets).
EPSE respond to specific drugs which can be prescribed against them, such as procyclidine. In long-term use, they can cause grimacing and involuntary movements, tardive dyskinesia. Newer drugs such as olanzepine (atypical antipsychotics) are claimed to have fewer side effects overall, and this is probably true; however, this probably comes at the price of lower potency as an antipsychotic.
Olanzepine in particular is associated with weight gain, which is probably linked to the useful sedative properties of this drug. Particular care needs to be taken with the use of antipsychotics in elderly patients, especially with the atypicals, as there is concern about a possible increased risk of stroke.
MOOD STABILISERS These drugs are mainly used to even out the fluctuations in mood seen in bipolar affective disorder. In other words, they are preventative (prophylactic) medications.
They have to be taken long-term in order to work. If they are, the severity of relapse, whether depression or mania, is reduced, and the episodes of relapse are shorter and less severe. However, the effect is a partial one, not a cure.
Mood stabilisers in common use include
- lithium (a simple ion: we have no idea how it can work- but it seems to)
- carbamazepine
- sodium valproate
Lithium requires careful monitoring with blood tests, as high levels of lithium in the system are toxic. Kidney function also needs to be monitored as long-term kidney damage can occur.
Carbamazepine and valproate were introduced as anticonvulsants (that is, drugs against epilepsy). Their use was then extended into psychiatry. Lamotrigine and other anticonvulsants have also been tried and have their adherents.
Mood stabilisers are also used as adjuvant treatments in psychosis/ mania/ depression: although their effect alone would be weak and slow, they can have a useful "booster" effect on top of other treatment
FURTHER INFORMATION
|
