Rationale for Antidepressant Prescribing in Severe Depression
I will outline some of the thoughts I have in relation to antidepressant drug prescribing for young people wit severe depression.
A depression care pathway is enclosed to help show the path a young person might take through a child and adolescent mental health service.
Severe depression only with clearly established documented >5/9 clinical features with impairment. Ideally medication to be given with CBT/other therapy at the same time. NICE Guidance allows for initial prescribing of Fluoxetine. In younger teenagers under the age of 16 years would go for Fluoxetine 20 mg on alternate days for a week then Fluoxetine 20 mg od. Alternatively start on Fluoxetine 10 mg od (syrup) or half tablet of orodispersible Olena for two weeks then Fluoxetine 20 mg od. Usually this does will do and if not effective after 8 weeks then consider increase to Fluoxetine 40 mg or switch to Sertraline. Can go to 60 mg especially with co-morbid Bulimia nervosa. Fluoxetine works quite well in cases without comorbid PTSD/OCD where there are ruminations and high levels of anxiety. I have had good results with Fluoxetine in teenage girls who have been very depressed after Vitamin D deficiency, Hypothyroidism and Iron Deficiency Anaemia and girls prescribed Roaccutane for Acne.
Sertraline 25 mg for one week then Sertraline 50 mg od and the increasing to 100 mg , 150 mg then 200 mg od as maximum dose. I actually prefer this to Fluoxetine and start most on it as there is usually comorbid anxiety, PTSD, OCD. I tend to prescribe more in ASD cases with comorbid depression and anxiety disorders with a view to getting to 150 mg asap say over 4-8 weeks. Over the years I have not gone for 75 mg , 125 mg or 175 mg dosing. However stepwise dosing and regular monitoring of increase and decrease is good practice and good to do in Learning Disabilities cases with comorbid depression and trauma etc.
Lower doses of antidepressant need to be considered in children with epilepsy presenting with depression in most instances. If a child is on Phenytoin or other inducers one would expect to prescribe higher dose as Phenytoin is a potent inducer of hepatic metabolism. I have never prescribed an antidepressant for a child on Phenytoin. Nowadays other anti-epileptic drugs are preferred and if a child is on Lamotrigine, then an increase in this dose to 100 mg od if on a lower dose can be negotiated with Paediatrician to minimise polypharmacy.
How the medication is prescribed after and engaging interview and psychoeducation is important in ensuring compliance and treatment adherence.
Switchovers from Fluoxetine to Sertraline and vice versa can be considered. Escitalopram rather than Citalopram would be a preferred third agent. I would go for Escitalopram 2.5 mg to start with if needed in the washout phase of the first drug and then aim to gradually build up over several weeks in steps of 2.5 mg. Usually 5-12.5 mg is a good enough dose. Only once heard of a case of an boy with ASD and depression benefitting from Escitalopram 20 mg od.
Have prescribed SSRI alongside Stimulant in ADHD plus comorbid depression which is quite common, but oddly we do not see a lot this in CAMHS as ADHD is managed by Paediatrics. We should have a joint clinic with them but I think it’s all a bit political etc.
Mirtazapine 15 mg nocte increasing to Mirtazapine 30 mg if needed with need to check to QTc interval. I have only done this about 10 times in 15 years and consider it less effective. I know GP will combine tis agent with SSRI. The ECG QTc still has to be monitored on increasing doses of Citalopram, Escitalopram and Sertraline, with some knowledge of the child’s cardiac history.
Prior to the age of 18 years I would consider the use of Venlafaxine with a view to getting to the dose of 225 mg after 2-3 months. This is usually a last resort. I have not prescribed Duloxetine but would consider as it works in a similar way at higher doses.
I would not prescribe Amitriptylline and would usually stop this and Propranolol if GP has initiated in low dose and then referred to CAMHS.
Lamotrigine Monotherapy in Bipolar IV but not exceeding a dose of 100 mg as not supported in the literature.
Have prescribed Carbamazepine twice in Bipolar IV with some benefit.
A predominantly depressive presentation after treatment with Lithium in Bipolar Disorder is tricky as non-compliance is likely. If the young person can establish compliance with a Lithium and low dose of SSRI can be considered with weekly monitoring at least. In adults Fluvoxamine can be considered here but I have not prescribed this drug in young people.
Augmentation of SSRI with Aripiprazole or Quetiapine or Risperidone or Olanzapine. Maybe Aripiprazole is preferred but I think still 40% will have an increased rate of weight gain. Risperidone good if comorbid challenging behaviour in ASD/LD in initial dose of 0.25 mg titrated upwards. Dose of Risperidone not to exceed 4 mg in a day. Olanzapine better for augmentation in presence of severe agitation and psychotic features, when I would prefer to use the 5 mg velotab to get a quicker response. I think in ASD cases with comorbid depression and anxiety Aripiprazole is preferred and the start dose can be as low as 1 mg with upwards titration after review. After 7.5 mg there may be greater likelihood of accelerated weight gain and acute dystonic reaction which happened in a 13 year with ASD/depression/severe agitation in 2013. I usually keep the dose of Quetiapine under 150 mg as I have had cases of marked weight gain on 100 mg, 200 mg and exceeding 300 mg ( given in an inpatient unit in Bristol by locum).
Usually titrating up gradually but not too gradually as pharmacokinetics are usually non-linear.
A good therapeutic relationship goes a very long way.
Would need GP to prescribe as they can do mass electronic prescribing in the blink of an eye.