Side effects
Those listed in italics below denote common side effects. Central nervous system: dizziness, drowsiness, confusion, seizures, headache, anxiety, tremors, stimulation, weakness, insomnia, nightmares, extrapyramidal symptoms in geriatric patients, increased psychiatric symptoms, paresthesia
Cardiovascular: orthostatic hypotension, ECG changes, tachycardia, hypertension, palpitations, dysrhythmias
Eyes, ears, nose and throat: blurred vision, tinnitus, mydriasis
Gastrointestinal: dry mouth, nausea, vomiting, paralytic ileus, increased appetite, cramps, epigastric distress, jaundice, hepatitis, stomatitis, constipation, taste change
Genitourinary: urinary retention
Hematological: agranulocytosis, thrombocytopenia, eosinophilia, leukopenia
Skin: rash, urticaria, diaphoresis, pruritus, photosensitivity

Overdose
Interactions
Pharmacology
Pharmacodynamics
Imipramine affects numerous neurotransmitter systems known to be involved in the etiology of depression, anxiety, attention-deficit hyperactivity disorder (ADHD), enuresis and numerous other mental and physical conditions. Imipramine is similar in structure to some muscle relaxants, and has a significant analgesic effect and, thus, is very useful in some pain conditions. The mechanisms of imipramines actions include, but are not limited to, effects on:

Serotonin: very strong reuptake inhibition. Norepinephrine: strong reuptake inhibition. Desipramine has more affinity to norepinephrine transporter than imipramine. Dopamine: imipramine blocks D2 receptors. Imipramine, and its metabolite desipramine, have no appreciable affinity for the dopamine transporter (Ki = 8,500 and >10,000 nM, respectively). Acetylcholine: imipramine is an anticholinergic, specifically an antagonist of the muscarinic acetylcholine receptors. Thus, it is prescribed with caution to the elderly and with extreme caution to those with psychosis, as the general brain activity enhancement in combination with the "dementing" effects of anticholinergics increases the potential of imipramine to cause hallucinations, confusion and delirium in this population. Epinephrine: imipramine antagonizes adrenergic receptors, thus sometimes causing orthostatic hypotension.
Sigma receptor: activity on sigma receptors is present, but it is very weak (Ki = 520 nM) and it is about half that of amitriptyline (Ki = 300 nM). Histamine: imipramine is an antagonist of the histamine H1 receptors. BDNF: BDNF is implicated in neurogenesis in the hippocampus, and studies suggest that depressed patients have decreased levels of BDNF and reduced hippocampal neurogenesis. It is not clear how neurogenesis restores mood, as ablation of hippocampal neurogenesis in murine models do not show anxiety related or depression related behaviours. Chronic imipramine administration results in increased histone acetylation (which is associated with transcriptional activation and decondensed chromatin) at the hippocampal BDNF promoter, and also reduced expression of hippocampal HDAC5. Pharmacokinetics
Within the body, imipramine is converted into desipramine (desmethylimipramine) as a metabolite. Chemistry
Imipramine is a tricyclic compound, specifically a dibenzazepine, and possesses three rings fused together with a side chain attached in its chemical structure. Other dibenzazepine TCAs include desipramine (N-desmethylimipramine), clomipramine (3-chloroimipramine), trimipramine (2′-methylimipramine or β-methylimipramine), and lofepramine (N-(4-chlorobenzoylmethyl)desipramine). Imipramine is a tertiary amine TCA, with its side chain-demethylated metabolite desipramine being a secondary amine. Other tertiary amine TCAs include amitriptyline, clomipramine, dosulepin (dothiepin), doxepin, and trimipramine. The chemical name of imipramine is 3-(10,11-dihydro-5H-dibenzo[b,f]azepin-5-yl)-N,N-dimethylpropan-1-amine and its free base form has a chemical formula of C19H24N2 with a molecular weight of 280.407 g/mol. The drug is used commercially mostly as the hydrochloride salt; the embonate (pamoate) salt is used for intramuscular administration and the free base form is not used.