Generic Name: Imipramine Hydrochloride, Imipramine Pamoate
Brand Names: Tofranil, Tofranil PM
Drug Class: TCA
Similar Class Drugs: Amoxipine, Maprotiline
Available Dosage Forms: Oral tablet and capsule
What is Imipramine?
Imipramine is an old-generation tricyclic antidepressant approved by the FDA for the second-line treatment of depression and as an adjunct to improve nocturnal enuresis in children aged 6 years or older.1 However, it is necessary to rule out other organic causes if the child has a pronounced frequency of daytime enuresis. Clinicians prefer safer alternatives over Imipramine due to its broad toxicity profile and narrow therapeutic index.1
Imipramine blocks the uptake of monoamines from the neuronal synapses, specifically serotonin. It affects the action of norepinephrine and acts as an antagonist to muscarinic, histamine (H1), and dopamine (D2) receptors.
Depression ignites a cascade of neuroinflammatory mechanisms, stimulates the production of proinflammatory molecules and white blood cells. In a study conducted by Ramirez and Sheridan, the animal subjects exhibited worsening social avoidance disorder and depression in response to a behavioral test called repeated social defeat.2 At an endogenous level, the mental stress-induced a surge in inflammatory biomarkers and enlargement of the spleen. Imipramine administration in animals reversed the inflammation-driven rise in corticosterone and IL6. It also revoked the accumulation of white blood cells in the brain and effectively reduced symptoms of depression.2
Imipramine is non-FDA approved for the management of:
– Neuropathic pain
– Panic disorder
How to use Imipramine?
– Dosage is prescribed based on your condition, age, and health factors
– In children with early night bedwetting, dosages are given in the afternoon and 1 hour before bedtime
– Do not restart imipramine dosages by yourself if you see a relapse and consult your doctor immediately
– It takes 1-3 weeks for Imipramine to exhibit therapeutic effects
What are the side effects of Imipramine?
– Antihistaminic effects
- Sedation, dizziness, delirium, seizures, increased appetite
– Anticholinergic effects
- Worsening of angle-closure glaucoma, urinary retention, paralytic ileus, prostatic hypertrophy, cardiac arrhythmias
– Serotonin syndrome, if used in combination with serotonergic drugs
– Mixed episodes in those with a history of bipolar disorder
– Suicidal behavior in children and young adults less than 24 years
Who should not use Imipramine?
– Those taking MAOIs
– Those with known hypersensitivity to Imipramine and similar drugs
– Patients in the recovery phase of myocardial infarction
References
- Fayez R, Gupta V. Imipramine. [Updated 2021 May 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557656/
- Ramirez K, Sheridan JF. Antidepressant Imipramine diminishes stress-induced inflammation in the periphery and central nervous system and related anxiety- and depressive-like behaviors. Brain Behav Immun. 2016 Oct;57:293-303. doi: 10.1016/j.bbi.2016.05.008. Epub 2016 May 17. PMID: 27223094; PMCID: PMC5010955.
