3 Clinical psychopharmacology3.3 Pharmacodynamics
3.3.2.4 Medicines for anxiety disorders
2 min read
Written by Resident Doctor Committee · Published
New in the 2027 syllabus
The College added this topic for exams from January 2027.
Choosing a treatment
The choice of drug depends on which anxiety disorder the person has and how severe it is. It also depends on how they responded to treatment before, any other illness they have, and whether they would prefer medication or a psychological treatment.
Selective serotonin reuptake inhibitors (SSRIs) are commonly used for persistent anxiety disorders. They help over weeks, not after a single dose.
When people first start an SSRI, they can feel more anxious or agitated, or sleep badly. This is called initial activation. Start cautiously and review how well the person is tolerating the drug. This makes it more likely they will keep taking it.
Drug class | How it acts | Main drawbacks |
|---|---|---|
SSRIs | Block the reuptake of serotonin | Gut side effects, sexual dysfunction, activation and withdrawal symptoms |
Serotonin-noradrenaline reuptake inhibitors (SNRIs) | Block the reuptake transporters for both serotonin and noradrenaline | Side effects similar to SSRIs; some SNRIs raise blood pressure |
Pregabalin | Binds the alpha-2-delta subunit of voltage-gated calcium channels | Dizziness, sedation, misuse and dependence |
Benzodiazepines | Increase the effect of gamma-aminobutyric acid (GABA) at GABA-A receptors | Sedation, poor coordination, tolerance and dependence |
Buspirone | Partial agonist at serotonin 5-HT1A receptors | Benefit is delayed, so it is not an immediate rescue treatment |
Generalised anxiety disorder
If the person chooses medication, an SSRI is one option.
If the first SSRI does not work or is not tolerated, try a different SSRI or an SNRI.
Pregabalin is an option when the person cannot tolerate these antidepressants. Before prescribing it, assess their risk of dependence, check renal function and consider reproductive safety.
Keep benzodiazepines for brief crisis management. They are not a routine long-term treatment.
Panic and physical symptoms
Panic disorder can respond to a suitably chosen antidepressant, given alongside cognitive behavioural therapy (CBT). Starting at a low dose can reduce early activation.
NICE guidance says benzodiazepines should not be prescribed to treat panic disorder.
Propranolol can reduce physical symptoms such as tremor or palpitations. It does not treat persistent worry, avoidance or panic disorder in general.
Reviewing treatment
Judging response: look at day-to-day function, avoidance and distress, not just the number of symptoms. If treatment seems to have failed, check the dose, how long it has been taken, and whether the person is actually taking it.
Withdrawal: missed doses or a quick dose reduction can cause withdrawal symptoms that look like the anxiety coming back. This is more likely with shorter-acting medicines.
Alcohol and opioids: these add to the sedation and breathing risks of benzodiazepines and other sedating drugs.
Stopping: when stopping an established antidepressant or a medicine that can cause dependence, taper it gradually to reduce the risk of withdrawal.