11 - Restarting psychotropic medications after a p

Restarting psychotropic medications after a period of non-compliance

Prescribing psychotropics CHAPTER 14 Restarting psychotropic medications after a period of non-­compliance When a patient is admitted to hospital it is often because they have been non-­compliant with their medications for some time before admission. The clinical question of whether to restart the medication and at which dose is a complex one. The risk of withdrawal symptoms and relapse must be balanced against the risk of adverse drug reactions when medications are reintroduced too quickly. There is little published evidence on this area, with most guidance (often of undeclared provenance) coming from manufacturers. The guidance below should be followed with caution. Summaries of product characteristics (SPCs) and other formal, regulatory documents tend not to deal with the issue of restarting medication. Official patient information leaflets sometimes give detailed advice. These leaflets are unanimous in advising that on no account should a double dose be given to make up for a missed dose. However, the vast majority of leaflets advise only on what to do if a single dose has been missed. Some leaflets advise taking the missed dose later (providing it is not too close to the next dose), whereas others recommend skipping the missed dose altogether and starting again with the next dose. In the event that more than one dose has been missed, the first question to ask is whether or not this is the appropriate drug for a patient to be taking. Poor compliance often indicates some dissatisfaction on the part of the patient. If it is a drug with a short half-­life or one that requires lengthy re-­titration, it may not be appropriate to restart prescribing for a patient who is frequently non-­compliant. Similarly, if a patient is intoxicated with alcohol or drugs, it may not be sensible to restart medication at that time. Efforts should be made to find out if there are any particular reasons for non-­ compliance. Where poor adherence is a result of factors other than tolerability, consider the use of a long-­acting injection (although these are only used, officially at least, in schizophrenia and schizoaffective disorder). When considering whether to restart the drug at the same dose as before or to re-­titrate from a lower dose, the time since the last dose is vitally important. If more than a week or two has passed, then all drugs will probably need to be restarted as if it is new treatment (although for many drugs that do not require titration this might mean starting back on the same dose as before). Exceptions include long-­acting depot formulations and oral drugs with long half-­lives such as aripiprazole, cariprazine and penfluridol. With these, there is a need to reload if the gap in treatment is very long, although shorter gaps (<2 weeks) might be managed by giving the usual dose and then reverting to the original dosing schedule. Lamotrigine must be considered separately from all other psychotropics because it has been associated with life-­threatening cutaneous reactions, especially with high initial doses. The manufacturer’s product information advises that if five half-­lives have elapsed since the last lamotrigine dose was given, lamotrigine should be titrated as if for the first time. The half-­life in healthy subjects on no other medication is around 33 hours. This is affected by other medications and is approximately 14 hours when given with glucuronidation-­inducing drugs such as carbamazepine or phenytoin. The half-­life is increased to approximately 70 hours when given with valproate. This means that the time before complete re-­titration is necessary varies between 3 and 7 days, depending on other drugs co-­prescribed.1 Table 14.4 summarises some very general recommendations. The drugs in the first column have specific safety issues that mean they require re-­titration after the specified