2017

An anti-obesity drug should be considered only for those with a body mass index (BMI, individual’s body-weight divided by the square of the individual’s height) of 30 kg/m2 or greater in whom at least 3 months of managed care involving supervised diet, exercise and behaviour modification fails to achieve a realistic reduction in weight. In the presence of risk factors (such as diabetes, coronary heart disease, hypertension, and obstructive sleep apnoea), it may be appropriate to prescribe a drug to individuals with a BMI of 27 kg/m2 or greater, provided that such use is permitted by the drug’s marketing authorisation.

Tricyclic and related antidepressants block the re-uptake of both serotonin and noradrenaline, although to different extents. Tricyclic and related antidepressants also show varying degrees of antimuscarinic side-effects and cardiotoxicity in overdosage, which may be important in individual patients. Evidence of the efficacy of tricyclic antidepressants for depression in children has not been established.

Drugs are used in mania to control acute attacks and to prevent their recurrence.

Antidepressant drugs are effective for treating moderate to severe depression associated with psychomotor and physiological changes such as loss of appetite and sleep disturbance; improvement in sleep is usually the first benefit of therapy.

Long-acting depot injections are used for maintenance therapy especially when compliance with oral treatment is unreliable. However, depot injections of conventional antipsychotics may give rise to […]

The 'atypical antipsychotics' may be better tolerated than other antipsychotics; extrapyramidal symptoms may be less frequent than with older antipsychotics. the atypical antipsychotics should be considered when choosing first-line treatment of newly diagnosed schizophrenia. an atypical antipsychotic is considered the treatment option of choice for managing an acute schizophrenic episode when discussion with the individual is not possible. an atypical antipsychotic should be considered for an individual who is suffering unacceptable side-effects from a conventional antipsychotic. an atypical antipsychotic should be considered for an individual in relapse whose symptoms were previously inadequately controlled. changing to an atypical antipsychotic is not necessary if a conventional antipsychotic controls symptoms adequately and the individual does not suffer unacceptable side-effects.

When prescribing an antipsychotic for administration on an emergency basis, the intramuscular dose should be lower than the corresponding oral dose (owing to absence of first-pass effect), particularly if the patient is very active (increased blood flow to muscle considerably increases the rate of absorption). The prescription should specify the dose for each route and should not imply that the same dose can be given by mouth or by intramuscular injection. The dose of antipsychotic for emergency use should be reviewed at least daily.

Most anxiolytics (sedatives) will induce sleep when given at night and most hypnotics will sedate when given during the day. Prescribing of these drugs is widespread but dependence (both physical and psychological) and tolerance occurs. This may lead to difficulty in withdrawing the drug after the patient has been taking it regularly for more than a few weeks. Hypnotics and anxiolytics should, therefore, be reserved for short courses to alleviate acute conditions after causal factors have been established. Benzodiazepines are the most commonly used anxiolytics and hypnotics; they act at benzodiazepine receptors which are associated with gamma-aminobutyric acid (GABA) receptors. Older drugs such as meprobamate and barbiturates are not recommended—they have more side-effects and interactions than benzodiazepines and are much more dangerous in overdosage.