31st January 2024

Sedatives

Background

This class of substances includes benzodiazepines and other substances such as Z-hypnotics and barbiturates. They are typically prescribed for short-term treatment of anxiety or insomnia and can also be used as a form of sedation for medical procedures. However, the feelings of elation they induce make them a commonly abused class of medications., and many people can remain on them for several years. It is recognised that they have a harmful side effect profile, and where able, efforts should be made to encourage cessation. They act on GABA receptors, increasing the effect of this inhibitory neurotransmitter.

Presentation 

Sedative use can cause sedation, speech impairment, inattention, reduced anxiety, euphoria, ataxic gait, mydriasis, respiratory depression and coma (in overdose). Withdrawal can cause seizures, tremor and hallucinations.

Diagnosis

As previously discussed, a careful history and examination will be required if a person presents with signs and/or symptoms of sedative overdose or withdrawal. Where required, a neurological examination and delirium screen may be needed, depending on presentation, as well as a workup for any other suspected cause of symptoms. Short-acting benzodiazepines can be detected in urine for 1-3 days, whereas long-acting benzodiazepines can be detected for up to 6 weeks post-ingestion.

Differential diagnosis

The gait imbalance and hyporeflexia that can occur could mimic a stroke event, and seizures or hallucinations could also have an organic component that would need to be ruled out via appropriate investigation, such as CT head. Withdrawal could also mimic alcohol withdrawal, especially if seizures occur.

Management

The dependence-inducing properties are related to the dose and duration of sedative use, and long-term prescribing of these drugs is not considered to be beneficial. To prevent withdrawal, clinicians should continue a current prescription but gradually taper the dose down, until the medication has been stopped. Benzodiazepines specifically can be tapered down by ⅛ of the daily dose every 2 weeks; however, this should be guided by the patient’s symptoms and may take several months to achieve.

Benzodiazepine overdose specifically can be treated with flumazenil, which acts as a benzodiazepine antagonist; however, it can provoke seizures and is quite short-acting. Withdrawal can produce sudden and severe symptoms, hence the need for gradual tapering and cessation. In emergency presentations, such as where an airway is compromised, an A to E approach should be followed in the first instance, and senior help sought.

If methadone is being taken concurrently with sedatives, this dose should be kept stable whilst sedative dosing is altered, if needed, to avoid dual detoxification. Physical and mental health issues that may have prompted sedative use initially should also be addressed as part of wider management and to support abstinence, e.g., psychosocial therapies, counselling and support groups.

References

• Weaver MF. Prescription Sedative Misuse and Abuse. Yale J Biol Med. 2015;88(3):247-256.
• Clinical Guidelines on Drug Misuse and Dependence Update 2017 Independent Expert Working Group. Drug misuse and dependence: UK guidelines on clinical management. UK: Department of Health; 2017.
• Stringer S, Church L, Keynejad R, Hurn J. Psychiatry P.R.N.: Principles, reality, next steps. Oxford: Oxford University Press; 2020.