Selegiline: L-deprenyl; C13H17N
Brand names: Movergan, Antiparkin, Xilopar and as a generic drug
1. Mechanisms of action of Selegiline¶
Selegiline is an MAO inhibitor that is primarily used for Parkinson’s disease. In low doses, it is a selective MAO-B inhibitor.
Selegiline irreversibly inhibits MAO-B, which reduces the breakdown of dopamine. Selegiline itself is metabolized to amphetamines or methamphetamines.
At higher doses (over 20 mg/day), selegiline also inhibits MAO-A, which increases serotonin and noradrenaline levels in the brain.
Selegiline also acts as a dopamine reuptake inhibitor.
2. Selegiline for ADHD¶
A study comparing 20 mg and 60 mg selegiline against placebo found no improvement in ADHD symptoms in the subjects’ self-report. Another study of 24 children with ADHD and comorbid Tourette’s found only slight improvements in ADHD symptoms with a high dropout rate among participants
An older study found a good improvement in ADHD symptoms with selegiline in children with ADHD and comorbid tic disorder over a test period of more than 6 months. Only 2 of the 29 subjects reported an exacerbation of tics. The side effects were minor.
Three smaller studies found no differences in effect between selegiline and methylphenidate in the parent report of 15 families, in the parent and teacher report of 28 children, and in the parent and teacher report of 40 children.
In another small placebo-controlled study, selegiline only improved inattention, but not hyperactivity/impulsivity. In animal studies, a significant reduction in impulsivity was found in SHR (animal model for ADHD-C) at 0.25 mg/kg
Selegiline sometimes appears to be used off-label for ADHD.
3. Side effects of Selegiline¶
- Dizziness
- Nausea
- Vomiting
- Dry mouth
- Movement disorders
- Psychoses
- Drop in blood pressure
- moderate increase in liver enzymes
The side effects of
- Loss of appetite
- Sleep problems
- Headache
were somewhat rarer with selegiline than with methylphenidate, with an otherwise comparable number of side effects.
4. Contraindications of Selegiline¶
- Extrapyramidal syndromes that are not due to dopamine deficiency
- Impaired kidney or liver function
- Stomach or intestinal ulcers
- Pregnancy and breastfeeding
Selegiline must not be combined with:
-
SSRI
-
SNRI
- tricyclic antidepressants
- Sympathomimetics
- Pethidine
- Opioids
- Serotonin agonists
- Bupropion
A study on the comedication of stimulants and MAO inhibitors in depression found no problems. Another study reported successful comedication of selegiline and lisdexamfetamine (Elvanse) in ADHD and comorbid depression
Thus, a combination medication of selegiline with stimulants can also be considered for ADHD.
