Imipramine Hydrochloride

Warning

H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]

P264, P270, P301+P317, P330, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 92 reports by companies from 4 notifications to the ECHA C&L Inventory.；Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

IMAP assessments - 5H-Dibenz[b,f]azepine-5-propanamine, 10,11-dihydro-N,N-dimethyl-, monohydrochloride: Human health tier I assessment；IMAP assessments - 5H-Dibenz[b,f]azepine-5-propanamine, 10,11-dihydro-N,N-dimethyl-, monohydrochloride: Environment tier I assessment

Obtain an ECG and immediately initiate cardiac monitoring. Protect the patient's airway, establish an intravenous line and initiate gastric decontamination. A minimum of 6 hours of observation with cardiac monitoring and observation for signs of CNS or respiratory depression, hypotension, cardiac dysrhythmias and/or conduction blocks, and seizures is necessary. If signs of toxicity occur at anytime during this period, extended monitoring is required. (L1712)

Imipramine works by inhibiting the neuronal reuptake of the neurotransmitters norepinephrine and serotonin. It binds the sodium-dependent serotonin transporter and sodium-dependent norepinephrine transporter preventing or reducing the reuptake of norepinephrine and serotonin by nerve cells. Depression has been linked to a lack of stimulation of the post-synaptic neuron by norepinephrine and serotonin. Slowing the reuptake of these neurotransmitters increases their concentration in the synaptic cleft, which is thought to contribute to relieving symptoms of depression. In addition to acutely inhibiting neurotransmitter re-uptake, imipramine causes down-regulation of cerebral cortical beta-adrenergic receptors and sensitization of post-synaptic serotonergic receptors with chronic use. This leads to enhanced serotonergic transmission.

Antagonism of the histamine H₁ and α₁ receptors can lead to sedation and hypotension. Antimuscarinic and anticholinergic side effects such as blurred vision, dry mouth, constipation and urine retention may occur. Cardiotoxicity may occur with high doses of imipramine. Cardiovascular side effects in postural hypotension, tachycardia, hypertension, ECG changes and congestive heart failure. Psychotoxic effects include impaired memory and delirium. Induction of hypomanic or manic episodes may occur in patients with a history of bipolar disorder. Withdrawal symptoms include GI disturbances (e.g. nausea, vomiting, abdominal pain, diarrhea), anxiety, insomnia, nervousness, headache and malaise.

Drug Induced Liver Injury Rank (DILIrank 2.0)

Imipramine hydrochloride

vLess-DILI-concern

3

Adverse reactions

DOI:10.1016/j.drudis.2016.02.015

◉ Summary of Use during Lactation；Milk levels of imipramine and its metabolite are low and have not been detected in the serum of breastfed infants. Immediate side effects have not been reported and a limited amount of follow-up has found no adverse effects on infant growth and development. Imipramine use during breastfeeding would usually not be expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months. A safety scoring system finds imipramine use to be possible during breastfeeding. Some experts consider imipramine one of the antidepressants of choice for nursing mothers. However, other agents may be preferred when large doses are required or while nursing a newborn or preterm infant.；◉ Effects in Breastfed Infants；No behavioral or physical changes were noted in a 6-week-old breastfed infant whose mother had been taking imipramine 200 mg daily at bedtime for 15 days.；Follow-up for 1 to 3 years in 14 breastfed infants whose mothers were taking imipramine in an average dosage of 161 mg daily (range 125 to 225 mg daily) found no adverse effects on growth and development.；Four infants were breastfed for 7 to 18 weeks during maternal use of imipramine 75 to 150 mg daily starting at 2 weeks (3 infants) and 8 weeks (1 infant) postpartum. Formal testing indicated no adverse effects on infant development up to 30 months of age. The mother of 1 infant was taking haloperidol along with imipramine 150 mg daily.；In another study, 25 infants whose mothers took a tricyclic antidepressant during pregnancy and lactation were tested formally between 15 to 71 months and found to have normal growth and development. Some of the mothers were taking imipramine.；Six postpartum mothers diagnosed with panic disorder were successfully treated with imipramine 25 to 35 mg (mean 28 mg) daily starting at a mean of 5.9 weeks postpartum. Mothers were treated for a mean of 9.3 weeks. All mothers reported that no adverse effects occurred in their infants.；◉ Effects on Lactation and Breastmilk；Imipramine has caused increased prolactin levels and gynecomastia in nonpregnant, nonnursing patients. Galactorrhea has been reported rarely. The clinical relevance of these findings in nursing mothers is not known. The prolactin level in a mother with established lactation may not affect her ability to breastfeed.；An observational study looked at outcomes of 2859 women who took an antidepressant during the 2 years prior to pregnancy. Compared to women who did not take an antidepressant during pregnancy, mothers who took an antidepressant during all 3 trimesters of pregnancy were 37% less likely to be breastfeeding upon hospital discharge. Mothers who took an antidepressant only during the third trimester were 75% less likely to be breastfeeding at discharge. Those who took an antidepressant only during the first and second trimesters did not have a reduced likelihood of breastfeeding at discharge. The antidepressants used by the mothers were not specified.；A retrospective cohort study of hospital electronic medical records from 2001 to 2008 compared women who had been dispensed an antidepressant during late gestation (n = 575) to those who had a psychiatric illness but did not receive an antidepressant (n = 1552) and mothers who did not have a psychiatric diagnosis (n = 30,535). Women who received an antidepressant were 37% less likely to be breastfeeding at discharge than women without a psychiatric diagnosis, but no less likely to be breastfeeding than untreated mothers with a psychiatric diagnosis. None of the mothers were taking imipramine.；In a study of 80,882 Norwegian mother-infant pairs from 1999 to 2008, new postpartum antidepressant use was reported by 392 women and 201 reported that they continued antidepressants from pregnancy. Compared with the unexposed comparison group, late pregnancy antidepressant use was associated with a 7% reduced likelihood of breastfeeding initiation, but with no effect on breastfeeding duration or exclusivity. Compared with the unexposed comparison group, new or restarted antidepressant use was associated with a 63% reduced likelihood of predominant, and a 51% reduced likelihood of any breastfeeding at 6 months, as well as a 2.6-fold increased risk of abrupt breastfeeding discontinuation. Specific antidepressants were not mentioned.

Exclusively metabolized by the liver. Imipramine is converted in the liver by various CYP isoenzymes (e.g. CYP1A2, CYP2D6, CYP3A4, CYP2C9) to active metabolites desipramine and 2-hydroxydesipramine. Route of Elimination: Approximately 40% of an orally administered dose is eliminated in urine within 24 hours, 70% in 72 hours. Small amounts are eliminated in feces via the biliary elimination. Half Life: Imipramine - 8-20 hours; Desipramine (active metabolite) - up to 125 hours

IMIPRAMINE HYDROCHLORIDE

Tricyclic Antidepressant [EPC]

Substances that contain a fused three-ring moiety and are used in the treatment of depression. These drugs block the uptake of norepinephrine and serotonin into axon terminals and may block some subtypes of serotonin, adrenergic, and histamine receptors. However, the mechanism of their antidepressant effects is not clear because the therapeutic effects usually take weeks to develop and may reflect compensatory changes in the central nervous system.

Drugs that block the transport of adrenergic transmitters into axon terminals or into storage vesicles within terminals. The tricyclic antidepressants (ANTIDEPRESSIVE AGENTS, TRICYCLIC) and amphetamines are among the therapeutically important drugs that may act via inhibition of adrenergic transport. Many of these drugs also block transport of serotonin.

For the relief of symptoms of depression and as temporary adjunctive therapy in reducing enuresis in children aged 6 years and older. May also be used to manage panic disorders, with or without agoraphobia, as a second line agent in ADHD, management of eating disorders, for short-term management of acute depressive episodes in bipolar disorder and schizophrenia, and for symptomatic treatment of postherpetic neuralgia.