Imipramine: Uses, Dosage, Side Effects & Precautions

At a Glance

What is Imipramine?

Imipramine is the original tricyclic antidepressant (TCA). It is used mainly to relieve symptoms of depression and, in children aged 6 years and older, as a temporary add-on treatment for bedwetting. Some doctors also use it off-label for panic disorder or anxiety. It must be taken under a doctor’s supervision because of risks to mood, the heart and the nervous system.

How Imipramine Works

Imipramine is thought to block the reuptake of norepinephrine and serotonin, two neurotransmitters that help regulate mood. This raises their levels at nerve endings, which over days to weeks can improve mood and depressive symptoms. The exact mechanism of action is not definitely known. In bedwetting, its effect is thought to be separate from its antidepressant action.

When Imipramine Is Used

• Depression: The US label covers relief of symptoms of depression in adults. Endogenous depression is more likely to be relieved than other depressive states. It is not approved for pediatric patients for depression.

• Childhood bedwetting (enuresis): The US label covers its use as temporary adjunctive therapy to reduce bedwetting in children aged 6 years and older, after possible organic causes have been excluded by appropriate tests. The effectiveness of treatment may decrease with continued use, and safety and effectiveness in children under 6 years have not been established.

• Anxiety and panic attacks (off-label): Doctors may prescribe imipramine off-label for certain anxiety disorders or panic disorder. This should be decided and monitored by a doctor.

Dosage and How to Take It

The dose depends on the condition, your age, how you respond and your tolerance. The examples below come from US prescribing information for imipramine tablets and are general information only. Dosing must be individualized and determined by your doctor, starting low and increasing gradually.

• Depression, adult outpatients: Treatment usually starts at 75 mg a day, which may be increased to 150 mg a day. Doses above 200 mg a day are not recommended for outpatients. The usual maintenance dose is 50 to 150 mg a day.

• Depression, hospitalized adults (closely supervised): Treatment usually starts at 100 mg a day in divided doses, gradually increased to 200 mg a day as required. If there is no response after two weeks, the label allows an increase to 250 to 300 mg a day in these supervised patients. Higher doses are not routine and are used only under close medical supervision.

• Adolescents and older adults: The label lists lower starting doses, usually 30 to 40 mg a day, and says it is generally not necessary to exceed 100 mg a day. The same label also states that imipramine is not approved for use in pediatric patients for depression, so use of imipramine for depression in people under 18 is a specialist decision.

• Childhood bedwetting (ages 6 and older): Treatment starts at 25 mg a day, given one hour before bedtime. If there is no satisfactory response within a week, the dose may be increased to 50 mg nightly in children under 12 years, or up to 75 mg nightly in older children. A daily dose above 75 mg does not improve effectiveness and tends to increase side effects. The daily dose should not exceed 2.5 mg/kg. This is temporary adjunctive therapy, so doctors review the need for treatment, and after an adequate trial with a good response they may consider a drug-free period. Any treatment break or dose reduction must be directed by the child’s doctor, and the dose should be tapered gradually rather than stopped abruptly.

• Taking it: Take it exactly as prescribed, at the same times each day. Do not stop suddenly. Your doctor will reduce the dose gradually.

Take this medicine only as advised by your doctor. Do not change the dose on your own.

Side Effects

Common effects may include:

• Dry mouth, constipation and blurred vision

• Dizziness, drowsiness and lightheadedness on standing (orthostatic)

• Urinary difficulty

• Fast heartbeat or palpitations

• Sweating

• Weight changes

• Sexual side effects

Serious effects need prompt medical attention:

• Important mood or behavior changes: worsening depression, suicidal thoughts or behavior, agitation, irritability or unusual changes in behavior, especially in children, teenagers and young adults and especially in the first few months or when the dose changes. Contact your doctor right away, and call emergency services or a crisis helpline if you or someone you know is in danger.

• Heart rhythm or conduction problems: fainting, a very fast, slow or irregular heartbeat, or chest pain

• Seizures

• Angle-closure glaucoma: eye pain or sudden vision changes

• Severe urinary retention: being unable to pass urine

• Mania or psychosis: unusually elevated mood, overactivity or confusion

• Serotonin syndrome (mainly when combined with other serotonergic medicines): agitation, fever, sweating, tremor or muscle stiffness

• Blood and liver problems: fever, sore throat, unusual bruising, or yellowing of the skin or eyes

• Low blood sodium (hyponatremia): confusion, headache or weakness, especially in older people

• Overdose: Overdose of tricyclic antidepressants can be medically serious. Seek emergency care right away.

Precautions and Monitoring

• Contraindications: Imipramine is contraindicated with monoamine oxidase inhibitors (MAOIs). When switching, a minimum of 14 days should elapse between stopping an MAOI and starting imipramine, and between stopping imipramine and starting an MAOI. It is also contraindicated during the acute recovery period after a heart attack and in people with known hypersensitivity to it (cross-sensitivity to related dibenzazepine compounds is possible).

• Tell your doctor before use if you have heart disease or rhythm problems, seizures, glaucoma, an enlarged prostate or trouble passing urine, thyroid problems, liver disease, bipolar disorder or a history of mania. These conditions call for caution, and your doctor decides whether imipramine is suitable.

• Mood monitoring: All patients starting an antidepressant should be watched for worsening depression, suicidal thoughts and unusual changes in behavior. Families and caregivers should be alerted to report such changes to the prescriber, especially in people 24 years of age and younger.

• Heart monitoring: Because imipramine can affect heart rhythm and blood pressure, doctors may arrange an ECG and check blood pressure, particularly in older people, in people with heart disease or risk factors, or at higher doses. Not everyone needs an ECG, and your doctor decides.

• Safe medicine use: Take only the prescribed amount, store medicines securely and keep them away from children, because overdose can be serious. Seek emergency care for any suspected overdose. Doctors may prescribe the smallest quantity consistent with good care.

• Alcohol, driving and machinery: Alcohol can add to drowsiness and other effects, and imipramine can cause drowsiness or dizziness, so take care driving or operating machinery.

• Do not stop suddenly. Abruptly stopping after prolonged treatment may cause discontinuation symptoms such as nausea, headache and malaise. This is not a sign of addiction. Follow your doctor’s plan for lowering the dose gradually.

Drug Interactions

Interactions can be serious, so always check with your doctor or pharmacist. Not every combination is prohibited, and your doctor will decide what is appropriate and how closely to monitor you.

• MAOIs: The combination is contraindicated and can cause serious or fatal reactions. Allow at least 14 days between stopping one and starting the other.

• Other antidepressants and serotonergic medicines: can increase the risk of serotonin syndrome. Some medicines, such as certain SSRIs (for example fluoxetine and paroxetine), can also raise imipramine blood levels.

• Medicines that affect heart rhythm (such as some antiarrhythmics, and thyroid medicines): may increase the risk of rhythm and conduction problems.

• Medicines that increase imipramine levels (such as methylphenidate and cimetidine): may increase imipramine’s effects and side effects, so doses may need adjusting.

• Sympathomimetic medicines (such as epinephrine, ephedrine or phenylephrine, including some cold and nasal products): may raise blood pressure or heart rate.

• Alcohol, sedatives and other CNS depressants: may increase drowsiness. Imipramine may enhance the central nervous system depressant effects of alcohol.

• Other anticholinergic medicines: may add to dry mouth, constipation, urinary retention and blurred vision.

Tell your doctor and pharmacist about all prescription medicines, over-the-counter medicines and supplements you take. This list is not complete.

Pregnancy and Breastfeeding

Pregnancy: Treatment during pregnancy needs an individual assessment by your doctor of the benefits and possible risks, and labeling varies by country (some labels advise avoiding it, particularly in the first trimester). Information from a teratology information service suggests imipramine is not expected to increase the chance of birth defects above the background risk, but newborns exposed during pregnancy can have temporary symptoms soon after birth, so tell your doctor if you are pregnant or planning pregnancy. Untreated depression can also affect you and your baby. Do not stop imipramine on your own.

Breastfeeding: Imipramine passes into breast milk in small amounts. Some product labels advise avoiding use during breastfeeding, while other sources report that side effects have not been reported in nursing infants. The decision should be individualized with your doctor. Do not stop breastfeeding or the medicine on your own.

Brands, Strengths and Approximate Price in India

Examples of imipramine brands marketed in India include Depsonil (Abbott) and Depsol (Intas), based on pharmacy listings. This is not an exhaustive list, and availability can change. Listings show 25 mg tablets.

These are listing-based prices, not guaranteed current MRPs, and the same product showed different values in different listings. Prices vary by brand, strength, pack size, pharmacy, location, availability and date.

How HealthPil Can Help

Medicines should be started, adjusted, or stopped only under the guidance of a qualified healthcare professional. If you have questions about imipramine, depression, anxiety or bedwetting, you can consult a doctor through HealthPil, including psychiatrists and mental health specialists who can guide treatment and monitoring.