Antipsychotics

Adherence to antipsychotic therapy is reported to be relatively poor, especially for schizophrenia¹; this can result in high relapse rates and florid illness which may increase the risk of events such as suicide. Non-adherence to antipsychotic therapy should be clearly distinguished from ‘treatment failure’ or ’treatment resistance’, which are also common in schizophrenia.

Factors which increase risk

The extent of a patient’s ‘insight’² into psychotic illness is thought to influence adherence to antipsychotic treatment; poor insight is frequently associated with non-adherence. Other important risk factors include history of non-adherence, concomitant use of alcohol and recreational drugs, and high level of patient-reported adverse effects, especially cognitive adverse effects and weight gain.

Risk-reduction measures

Frank discussion of diagnosis and treatment decisions with patients and, where applicable, with caregivers and family can help promote adherence or concordance³ with treatment. Using the lowest possible antipsychotic dose that achieves the required therapeutic response can help minimise adverse effects.

The medicine regimen should be simplified as much as possible by reducing both the number of capsules or tablets to be taken and the frequency at which they need to be taken.

Treatment

Open dialogue with patients, carers and family can help identify non-adherence and the reasons for it. Dialogue also serves to correct misconceptions about treatment or treatable adverse effects. Alternative antipsychotic formulations such as sublingual tablets or liquids may help with adherence. If non-adherence persists, use of a prolonged-release (‘depot’) antipsychotic injection can be considered.

Assaying antipsychotic in blood is generally not useful for monitoring adherence, but can be important for detecting toxicity (especially of clozapine).