Imipramine

Key takeaways

Imipramine belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Imipramine to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Imipramine from memory before moving on to harder problems.

Reference excerpt

Imipramine, sold under the brand name Tofranil, among others, is a tricyclic antidepressant (TCA) mainly used in the treatment of depression. It is also effective in treating anxiety and panic disorder. Imipramine is taken by mouth. Common side effects of imipramine include dry mouth, drowsiness, dizziness, low blood pressure, rapid heart rate, urinary retention, and electrocardiogram changes. Overdose of the medication can result in death. Imipramine appears to work by increasing levels of serotonin and norepinephrine and by blocking certain serotonin, adrenergic, histamine, and cholinergic receptors. Imipramine was discovered in 1951 and was introduced for medical use in 1957. It was the first TCA to be marketed. Imipramine and TCAs other than amitriptyline (which, at least in the U.K., is prescribed comparatively as frequently as SSRIs) have decreased in prescription frequency with the rise of SSRIs, which generally have more tolerable side effect and are far safer in overdose. Regardless of such caveats, imipramine retains importance in psychopharmacology and pediatrics (e.g., with childhood enuresis).

Medical uses Imipramine is primarily used for the treatment of depression and certain anxiety disorders, including acute post-traumatic stress reactions. A significant amount of research regarding its efficacy on acute post-traumatic stress in children and adolescents has focused on trauma resulting from burn-injuries. Although evidence for its efficacy in the treatment of chronic post-traumatic stress disorder appears to be less robust, it remains a viable treatment. Here, it may share a similar efficacy with the monoamine oxidase inhibitor phenelzine. Caution is needed in prescribing imipramine (and its commercially available metabolite, desipramine) in children and youth/adolescents (whether they suffer with, e.g., bed-wetting, recurrent panic attacks, acute trauma or, in the case of desipramine, ADHD), owing to possibility of accidental overdose, which may be of particular concern in children. In the treatment of depression, it has demonstrated similar efficacy to the MAOI moclobemide. It has also been used to treat nocturnal enuresis because of its ability to shorten the time of delta wave stage sleep, where wetting occurs. In veterinary medicine, imipramine is used with xylazine to induce pharmacologic ejaculation in stallions. It is also used for separation anxiety in dogs and cats. Blood levels between 150 and 250 ng/mL of imipramine plus its metabolite desipramine generally correspond to antidepressant efficacy.

Contraindications Combining it with alcohol consumption may cause more drowsiness, necessitating greater caution when drinking. It may be unsafe during pregnancy. Many MAOIs are known to have serious interactions with imipramine. It is often contraindicated during their use or in the two weeks following their discontinuation. This category includes medications such as isocarboxazid, linezolid, methylene blue, phenelzine, selegiline, moclobemide, procarbazine, rasagiline, safinamide, and tranylcypromine.

Side effects These side effects can be attributed to the multiple receptors that imipramine targets such as serotonin, norepinephrine, dopamine, acetylcholine, epinephrine, histamine. Those listed in italics below denote common side effects, separated by the organ systems that are affected. Some side effects may be beneficial in some cases, e.g. reduction of hyperactive gag reflex; reduced random or physical strain-linked urinary leakage.

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

Like other tricyclic antidepressants, imipramine has many medication interactions. Many MAOIs have serious interactions with this medication. Other categories of medications that may interact with imipramine include blood thinners, antihistamines, muscle relaxants, sleeping pills, thyroid medications, and tranquilizers. Some medications used for various conditions such as high blood pressure, mental illness, nausea, Parkinson's disease, asthma, colds, or allergies. Certain medications increase the risk of serotonin syndrome, including selective serotonin reuptake inhibitors (SSRIs), St. John's Wort, and drugs such as ecstasy. Other prescription drugs decrease the body's ability to eliminate imipramine. These include barbiturates, some antiarrhythmic medications, some antiepileptic drugs, and certain HIV drugs (protease inhibitors). Others may cause changes in the heart rhythm, such as QT prolongation. Alcohol and tobacco may interact with imipramine. Tobacco may decrease the medication's effectiveness.

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 imipramine's actions include, but are not limited to, effects on:

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Imipramine

Start with the simplest possible case. Write down what Imipramine claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Imipramine before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Imipramine ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Imipramine

In research: Imipramine appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Imipramine in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Imipramine is common in secondary-school and first-year university syllabi. It links to neighbouring topics Alpha-1 blockers, CYP2D6 inhibitors, D2 antagonists, so understanding it makes those chapters shorter.
In everyday life: Look for Imipramine outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Imipramine in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Imipramine means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Imipramine out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Imipramine in simple terms?

Imipramine, sold under the brand name Tofranil, among others, is a tricyclic antidepressant (TCA) mainly used in the treatment of depression. It is also effective in treating anxiety and panic disorder.

Why does Imipramine matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Imipramine?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Imipramine.